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Pelage of Columbian black tail deer odocoileus hemionus columbianus (Richardson) a study Raddi, Arvind Govind 1967

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THE PELAGE OP COLUMBIAN BLACK TAIL DEER ODOCOILEUS HEMIONMS COLUMBIANUS  (Richardson)  — a Study  by  ARVTND GOVIND RADDI 1957  B.Sc.  U n i v e r s i t y of Poona  M.Sc.  U n i v e r s i t y o f Bombay 1 9 5 9  A.I.F.C.  Indian F o r e s t C o l l e g e , Dehra Dun 1962  A T h e s i s s u b m i t t e d . i n p a r t i a l f u l f i l l m e n t of the requirements f o r the degree of Doctor o f P h i l o s o p h y i n the Department of  Zoology  We a c c e p t t h i s t h e s i s as conforming to the r e q u i r e d standard  U n i v e r s i t y of B r i t i s h November 1 9 6 7  Columbia  In  presenting  for  an  that  advanced  the  I  thesis  for  Department  shall  further  agree  the  make  freely  representatives.  h.Us  of  this  of  thesis  may  for  permission.  Zoology  1 4 t h December  Columbia  19^7»  be  of  for  granted  It  is  financial  of  British  available  permission  or  by  fulfilment  University  it  that  The U n i v e r s i t y o f B r i t i s h V a n c o u v e r 8, C a n a d a Date  partial  purposes  my w r i t t e n  Department  at  in  scholarly  publication  without  thesis  degree  Library  Study.  or  this  for  the  Columbia,  I  reference  and  extensive  by  the  requirements  copying  Head  understood  gain  shall  of  this  my  that  not  of  agree  be  copying  allowed  i  ABSTRACT  The h a i r s and the f o l l i c l e s the mammalian p i l a r y system.  i n which they a r i s e c o n s t i t u t e  I t i s a dynamic b i o l o g i c a l  system  i n which the h a i r f o l l i c l e s undergo c y c l i c a l l y p a r t i a l r e g r e s s i o n and redevelopment, producing  simultaneously new h a i r s t o r e p l a c e  the o l d which a r e due t o be shed. The pelage  i s important  i n m a i n t a i n i n g the animals  thermal  e q u i l i b r i u m , p r o t e c t i o n from a b r a s i o n and i n d i s p l a y e t c . Nonetheless, limited.  knowledge o f c e r v i d p i l a r y system i s extremely  The p r e s e n t study covers i t s development, morphology,  moult and the annual h a i r c y c l e .  E f f e c t s on the c e r v i d pelage o f  e x p e r i m e n t a l l y induced adverse n u t r i t i o n , as w e l l as v a r y i n g habitat, are a l s o studied. Morphogenesis o f f o l l i c l e s and development stages o f the h a i r f o l l o w the g e n e r a l mammalian p a t t e r n .  The d e t a i l s of  anatomy and development have been r e c o r d e d .  Large guard  hair  f o l l i c l e s , which d u r i n g development grow f a s t e r and a t t a i n dimensions,  larger  have been recorded f o r the f i r s t time i n u n g u l a t e s .  They a r e r e l a t e d t o " T y l o t r i c h s " r e f e r r e d t o by S t r a i l e  ( i 9 6 0 )  and produce l o n g e r h a i r . Both primary and secondary  f o l l i c l e s are present.  The  f i r s t formed secondaries a r e l a r g e r and like„the p r i m a r i e s possess a sweat gland, sebaceous gland and a r r e c t o r p i l i i L i k e p r i m a r i e s they too produce medullated  hairs.  secondaries form non medullated woolly u n d e r h a i r s . branched f o l l i c l e s have been r e c o r d e d amidst  muscle.  The l a t e r P a i r e d and  secondaries.  11 The p r i m a r i e s g i v e r i s e t o the overcoat and the secondaries to the  undercoat. The percentage  o f non medullated h a i r s i n the b i r t h coat of  the fawn i s l e s s than i n other c o a t s .  The h a i r f o l l i c l e s i n  which they a r i s e continue t o form p o s t n a t a l l y and become f u l l y f u n c t i o n a l i n fawn w i n t e r c o a t .  A d u l t w i n t e r coat d i f f e r s from  a d u l t summer coat i n c o l o u r a t i o n , l e n g t h and diameter, i s a g r e a t e r development o f medulla, undercoat  i s present.  summer c o a t .  and a w e l l developed  there  woolly  The l a t t e r i s f u n c t i o n a l l y l a c k i n g i n a d u l t  The autumn moult  spreads cephalad and caudad. The  here  ( a d u l t ) begins on the f l a n k s and I n the summer coat moult i s caudad.  fawn b i r t h coat moult i s caudad.  T h e i r d e t a i l s have been  documented. The w i n t e r coat i s g r e y i s h i n c o l o u r w h i l e the summer coat i s reddish yellow.  The w i n t e r c o l o u r a t i o n i s a product mostly o f  the c o l o u r zone i n the top 10 mm o f h a i r l e n g t h .  The w i n t e r  guard h a i r s stand more e r e c t , because o f the padding the w o o l l y undercoat.  clat  p r o v i d e d by  The a d u l t summer coat has more s l o p i n g  h a i r s and I t s c o l o u r a t i o n i s the product o f the top 20 mm o f the t o t a l hair length.  The c h a r a c t e r i s t i c s o f h a i r s c a l e a r e r e c o r d -  ed f o r r e p r e s e n t a t i v e h a i r  types.  A morphometric study o f h a i r samples from i d e n t i c a l r e g i o n s i n the c o a t s c o f t b l a c k t a i l deer has been attempted and the features recorded.  The h a i r i n c r e a s e s i n coarseness and diameter  from fawn b i r t h coat up t o a d u l t winter c o a t . i n c r e a s e s up to a d u l t summer coat but decreases coat.  The h a i r l e n g t h i n a d u l t winter  The w i n t e r coat e x h i b i t e d a c o n s i s t e n t l e n g t h t o diameter  r e l a t i o n s h i p but t h i s was l a c k i n g i n summer c o a t .  The h a i r s i n  iii w h i t e - s p o t s of the fawn b i r t h coat d i f f e r e d o n l y i n r e s p e c t o f c o l o u r from the a d j o i n i n g non-spotted a r e a and not i n any other external morphological respect. F o r t n i g h t l y s k i n biopsy samples were taken by means of a t r e p h i n e ; t h e i r h i s t o l o g i c a l study p r o v i d e d d a t a on the annual hair cycle.  The overcoat h a i r s moult twice w h i l e the undercoat  h a i r s a r e shed o n l y once. r a t e of f o l l i c l e  The statement by Lyne ( 1 9 6 6 ) t h a t "the  development I s i n v e r s e l y p r o p o r t i o n a l t o the  s i z e o f the mature f o l l i c l e " I s t r u e f o r guard h a i r s .  First  formed secondaries , however, r e a c h r e s t i n g stages e a r l i e r do the l a t e r formed s e c o n d a r i e s . larger f o l l i c l e s ,  than  Rate of growth i s greater,Jin  which though not much advanced developmentally,  reach l a r g e r size-. E f f e c t s of adverse n u t r i t i o n on pelage have been s t u d i e d e x p e r i m e n t a l l y , oh normally growing artificially  h a i r s as w e l l as those  by p l u c k i n g r e s t i n g h a i r s .  induced  H a i r l e n g t h and diameter  were reduced i n underfed animals and i n i t i a t i o n of new h a i r growth was d e l a y e d .  Reduction i n width of medulla appeared t o  be r e s p o n s i b l e f o r most of the r e d u c t i o n i n h a i r diameter.  The  medulla i s an important i n s u l a t o r , as can be seen from i t s g r e a t e r extent i n Alaskan forms compared with those from C a l i f o r n i a l i v i n g i n d r y hot h a b i t a t s .  Southern  Regression a n a l y s i s  I n d i c a t e d that i n underfed animals, though a c t u a l h a i r  diameter  was l e s s , r e l a t i v e i n c r e a s e i n diameter f o r a u n i t i n c r e a s e of l e n g t h was g r e a t e r than t h a t i n w e l l f e d a n i m a l s . n u t r i e n t s a r e l i m i t e d , growth i n h a i r diameter  Thus when  ( i n t u r n dependent  on s i z e of medulla) enjoys a p r i o r i t y over growth i n l e n g t h .  Finally i t i s felt  t h a t to comprehend  p r o p e r l y the  phenomenon of h a i r growth i n c e r v i d s f u t u r e i n v e s t i g a t i o n s could f r u i t f u l l y concentrate  on the b i o l o g y of c e l l s i n the f o l l i c l e  base and the dermal p a p i l l a .  The r o l e of dermal p a p i l l a i n h a i r  growth and the p r o c e s s of d i f f e r e n t i a t i o n of d i f f e r e n t f o l l i c l e l a y e r s a r e of g r e a t  s i g n i f i c a n c e but need to be w e l l understood.  v  I  ACKNOWLEDGEMENT I t i s a p l e a s u r e t o express my s i n c e r e g r a t i t u d e , t o my S u p e r v i s o r Dr. I McTaggart  Cowan, Dean, F a c u l t y of Graduate  s t u d i e s , U n i v e r s i t y of B r i t i s h Columbia f o r h i s guidance, encouragement and above a l l f o r the most understanding a t t i t u d e which he maintained throughout the course of my stay a t U.B.C. and t o Dr. J.K. L i n g f o r i n i t i a t i n g me i n t o the study of pelage and f o r h i s h e l p and guidance d u r i n g h i s tenure as a post d o c t o r a l f e l l o w a t the Dept. of Zoology.  S i n c e r e thanks a r e a l s o  due t o Dr. H.D. F i s h e r and Dr. C. Finnegan f o r p e r m i t t i n g the use of  their laboratory  facilities.  I a l s o thank Dr. P.J. Bandy and Mr. Don Blood of the B.C. F i s h and Game Dept. f o r t h e i r h e l p i n c o l l e c t i o n o f deer s k i n s , Dr. H.C. Nordan f o r h i s h e l p i n s e t t i n g up the n u t r i t i o n experiment, and Dr. P. Ford f o r h i s a d v i c e i n h i s t o l o g i c a l work. I a l s o thank Dr. Longhurst and Dr. K l i n e f o r s u p p l y i n g us w i t h h i d e s of Southern C a l i f o r n i a n and Alaskan b l a c k t a i l  deer.  I am a l s o t h a n k f u l t o my f r i e n d and c o l l e a g u e Dr. J a g d l s h C. N a u t i y a l of the I n d i a n F o r e s t S e r v i c e , then I n the F a c u l t y of F o r e s t r y , UBC, f o r h i s h e l p i n work i n v o l v i n g use of a computer. Mrs. H. Froese and Miss J . Osborne of the F a c u l t y of F o r e s t r y were a l s o most h e l p f u l i n t h i s  respect.  Many of my c o l l e a g u e s i n the D e p t ready t o h e l p .  i  of Zoology were always  I n p a r t i c u l a r I must thank Mr. Ray Addison who  helped time and time a g a i n d u r i n g s k i n b i o p s y sampling. I a l s o thank Mrs Jephson, who d i d the t y p i n g , f o r h e r p a t i e n c e w i t h the t h e s i s manuscript, and Miss R. B r o i l who t r a n s l a t e d some s c i e n t i f i c papers f o r me.  I am a l s o g r a t e f u l t o the E x t e r n a l A i d O f f i c e of the Government of Canada, f o r f i n a n c i a l support p r o v i d e d by award of a Canadian Commonwealth S c h o l a r s h i p , and to the Government of I n d i a and Government of Maharashtra f o r g r a n t i n g me study leave to u t i l i z e  the same.  I thank a l l the members of my a d v i s o r y committee f o r t h e i r h e l p f u l c r i t i c i s m , i n p a r t i c u l a r Dr. D. C h i t t y ; l i s t e n i n g t o h i s views on matters  s c i e n t i f i c or otherwise was an e n r i c h i n g  experience. F i n a l l y s p e c i a l thanks a r e due t o my wife Neelima f o r the very c h e e r f u l support and h e l p which she c o n s i s t e n t l y extended throughout  the course of t h i s  undertaking.  vii TABEL OF CONTENTS Chapter  Page Abstract  i  Acknowledgement  v  Table o f contents Table s  x  Illustrations I  II III  vii  x i i  General i n t r o d u c t i o n Introduction Humans Domestic animals o f economic Importance a) Sheep b) C a t t l e Animals with e c o n o m i c a l l y v a l u a b l e p e l t s  1 1 2 2 2 2 3  The c e r v i d pelage....  5  P r e n a t a l development of the p i l a r y system In deer Introduction. M a t e r i a l s and methods Observations F o l l i c l e and h a i r development Large guard h a i r f o l l i c l e s The i n t e r m e d i a t e guard h a i r f o l l i c l e s C e n t r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s . . . . L a t e r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s . . . . Woolly under h a i r f o l l i c l e s . . . . F o l l i c l e anatomy. The connective t i s s u e sheath The g l a s s y membrane E x t e r n a l r o o t sheath The i n n e r r o o t sheath Henle s layer Huxley's l a y e r Inner r o o t sheath c u t i c l e . The f i b r e anatomy The h a i r c u t i c l e The c o r t e x . . . . . . . . . . . . . . . ° The medulla The f o l l i c l e b u l b and dermal p a p i l l a Melanocytes Sweat g l a n d Sebaceous g l a n d A r r e c t o r p i l i l muscle Ental swelling The h a i r c a n a l Paired f o l l i c l e s 1  11 11 11 13 1 8 23 33 35 38 39 4 0 4 ? 4 ? 4 7 4 8 51 51 51 52 52 52 53 53 55 55 58 61 6l 62 62  viii Chapter III  Page 63 63 •> 64 64 64 67  Branched f o l l i c l e s F o l l i c l e density Integumentary l a y e r s The epidermis Periderm The dermis  70  Summary IV  74 74 7^ 76 76 76 76 79 79 79 79 82 85  Pelage morphology and moult p a t t e r n s Introduction M a t e r i a l and methods Observations Hair c h a r a c t e r i s t i c s Hair types.. Large guard h a i r s Intermediate guard h a i r s Woolly under h a i r s Beard type White t i p p e d h a i r s Cortex, medulla and s c u t e l l a t i o n Colouration Coat d e s c r i p t i o n . a n d p a t t e r n o f moult Fawn b i r t h coat Moult i n the fawn b i r t h coat Fawn winter coat Moult from fawn winter coat t o a d u l t summer coat Adult summer coat Moult from a d u l t summer t o a d u l t winter c o a t . A d u l t winter coat Moult from a d u l t winter coat t o a d u l t summer coat Summary V  The h a i r c y c l e of the b l a c k t a l l deer Introduction M a t e r i a l and methods Observations Summary  VI  The morphometry o f b l a c k t a i l deer Introduction M a t e r i a l and methods Observations Length Diameter C o l o u r a t i o n * ^ . . xsaa B l a c k coloured zone  87 87 89 93 93 9^ 95 99 99 103  105 105 105 ... 108 115 117 117 117 118 118 123 128 128  Yellcw c o l o u r e d zone Grey or r e d d i s h - y e l l o w c o l o u r e d zone. White c o l o u r e d zone Summary E f f e c t of adverse n u t r i t i o n and v a r i a t i o n of h a b i t a t on c e r v i d pelage Introduction. M a t e r i a l and methods Observations a) Normally grown w i n t e r pelage on c o n t r o l and experimental animals b) The a r t i f i c i a l l y induced h a i r c y c l e s . . . c) H i s t o l o g i c a l changes d u r i n g the a r t i f i c a l hair cycle Summary  «•  General d i s c u s s i o n . . . . . F o l l i c l e development and anatomy Epidermis and dermis H a i r types and morphology Adaptive v a l u e Moult E f f e c t o f adverse n u t r i t i o n Bibliography Appendices I II Ill IV  Weekly weight d a t a Feed i n t a k e i n c a l o r i e s average)  (weekly  H i s t o l o g i c a l treatment Key t o a b b r e v i a t i o n s used i n illustrations  LIST OP TABLES Number  -Page  1  B a s i c d a t a on f o e t u s e s sampled  12  2  F o l l i c l e types and  34  3  Annual c y c l e of the b l a c k t a i l deer  116  4-  Nested a n a l y s i s of v a r i a n c e h a i r l e n g t h  119  5  Lengths of h a i r samples i n mm  121  6  Duncan's m u l t i p l e range t e s t f o r h a i r l e n g t h s . a) W i t h i n coats b) Regions w i t h i n coats c) H a i r types w i t h i n r e g i o n s  122  7  Nested a n a l y s i s of v a r i a n c e h a i r diameter  123  8  Diameter of hair samples i n microns  126  9  Duncan*s m u l t i p l e range t e s t f o r h a i r i n microns a) W i t h i n coats b) Regions w i t h i n coats c) H a i r types w i t h i n r e g i o n s  t h e i r development s t a g e s . . .  diameter  10  B l a c k c o l o u r e d zone ( r a t i o of b l a c k c o l o u r e d zone to t o t a l h a i r l e n g t h  11  Nested a n a l y s i s of v a r i a n c e . ZOne  127  130  Black coloured 131  -r-r  12  Duncan's m u l t i p l e range t e s t f o r b l a c k c o l o u r e d zone a) W i t h i n coats b) Regions w i t h i n coats c) H a i r types w i t h i n r e g i o n s  13  Nested a n a l y s i s of v a r i a n c e . Yellow zone  coloured  14-  Yellow c o l o u r e d zone extent ( r a t i o of yellow c o l o u r e d zone to t o t a l h a i r l e n g t h  15  Duncan's m u l t i p l e range t e s t f o r yellow c o l o u r e d zone a) W i t h i n coats b) Regions w i t h i n coats c) H a i r types w i t h i n r e g i o n s  132  133 13^135  xi  LIST OF TABLES  (cont'd)  Number  Page  16  Nested a n a l y s i s of v a r i a n c e of g r e y / r e d d i s h y e l l o w zone  1 3 6  17  Grey or r e d d i s h - y e l l o w zone extent  1 3 7  18  Duncan's m u l t i p l e range t e s t f o r grey or r e d d i s h yellow zone a) W i t h i n coats b) Region w i t h i n coats c) H a i r types w i t h i n r e g i o n  19  White c o l o u r e d zone  20  Nested a n a l y s i s of v a r i a n c e . White c o l o u r e d zone  21  Duncan's m u l t i p l e range t e s t f o r white c o l o u r e d zone > a) W i t h i n coats b) Regions w i t h i n coats c) H a i r types w i t h i n r e g i o n  22  Composition  23  N u t r i e n t composition  24  D i g e s t i b l e energy content of the a d u l t r a t i o n . 1 5 6  25  Breaking  s t r e n g t h l a r g e guard h a i r s  26  Breaking  s t r e n g t h of i n t e r m e d i a t e guard h a i r s . 1 6 0  27  Intermediate  1 3 8  140  of a d u l t r a t i o n of r a t i o n  guard h a i r s  ( f i b r e weight)  •  1^-1 142  1 5 ^ 1 5 5  1 6 0  161  xii ILLUSTRATIONS Figures 1  Page Stages 1 t o 1 0 In the development of mammalian h a i r f o l l i c l e as shown i n c a t t l e . A f t e r Lyne and Heideman ( 1 9 5 9 )  2 3A 3B 4  1^  Grouping of primary and secondary f o l l i c l e s i n a d u l t deer. Transverse s e c t i o n  20  Deer primary f o l l i c l e s g e n e r a l view. Longitudinal section  20  Deer secondary f o l l i c l e . General view Longitudinal section..  20  Developing s k i n and h a i r 1 1 2 mm stage  20  follicles.  4.1  Longitudinal  section  20  5  Developing s k i n and h a i r 2 0 2 mm stage  5.1  Longitudinal  5.2  Transverse s e c t i o n  6  Developing s k i n and f o l l i c l e s . 2 3 5 Eim stage  6.1  Longitudinal  6 i 2".  Transverse s e c t i o n . . . .  7  Developing s k i n and f o l l i c l e s . 2 6 9 mm  7.1  Longitudinal  7.2  Transverse s e c t i o n  8  Developing s k i n and h a i r  follicles.  section  25 25  section  25 25  section.  stage 27 27  follicles.  2 8 7 nun stage 8.1  Longitudinal  section  8.2 9  Transverse s e c t i o n Developing s k i n and h a i r 3 2 1 mm stage  9.1  Longitudinal  9.2  Transverse s e c t i o n  section  27 27 follicles. 29 29  xiii ILLUSTRATIONS (cont»d) Figure  Page  10  Developing s k i n and h a i r 44-8 mm stage  10.1  Longitudinal  10.2  Transverse s e c t i o n  29  11  Large guard h a i r f o l l i c l e  31  11.1  L o n g i t u d i n a l s e c t i o n . 287  11.2  Transverse s e c t i o n with a d j o i n i n g 269 mm stage  11.3  Longitudinal 287  mm  follicles. 29  section  mm  31  stage follicles  31  s e c t i o n showing d i l a t e d  part 31  stage  11.4  Close  12 12.1  C e n t r a l i n t e r m e d i a t e guard h a i r Longitudinal section  12.2  Transverse s e c t i o n . . . . . . . .  13  White t i p p e d h a i r f o l l i c l e s (fawn b i r t h coat) and l a t e r a l intermediate guard h a i r f o l l i c l e s  13.1  Longitudinal cle  13.2  Transverse s e c t i o n . .  14  Secondary  14.1  Developing secondary f o l l i c l e s . section  14.2  P a i r e d secondary f o l l i c l e longitudinal section  14-.3  Branching secondary f o l l i c l e s . section  14.4  14-.5  of the f o l l i c l e bulb. 287  mm  stage  31  follicles.... 37 37  s e c t i o n white t i p p e d h a i r  folli-  37 37  follicles. Longitudinal  developing,  4-2 4-2  Longitudinal 4-2  F i r s t formed secondary f o l l i c l e s and l a t e r formed secondary f o l l i c l e s . L o n g i t u d i n a l section  4-2  P a i r e d secondary f o l l i c l e s . Adult Longitudinal section .'.  44  material.  xiv .ILLUSTRATIONS (cont»d) 'igures 14.6  Page Secondary f o l l i c l e . " A d u l t  material. 44  Longitudinal section 15  D e t a i l s of f o l l i c l e anatomy, (sheep)  15.1  Longitudinal  15.2  D e t a i l s of the b u l b . L o n g i t u d i n a l  15.3  D e t a i l s of medulla (sheep)  16  Deer primary f o l l i c l e  16.1  Close up of the f o l l i c l e  16.2  C e l l layers i n f o l l i c l e bulb  17  Medulla  17.1  Medulla i n primary h a i r f o l l i c l e  50  17.2  Medulla i n white t i p p e d h a i r of fawn b i r t h coat. Sweat gland  5 0  18  s e c t i o n of primary f o l l i c l e section  (sheep) 46 "  46 46  bulb 50  bulb  5 0  formation  18.1  Sweat gland forming. 2 0 2 mm longitudinal section  18.2  Sweat gland a t 2 3 6 mm Longitudinal section  stage.  18.3  Sweat gland a t 2 6 9 mm section  stage.  18.4  Sweat gland  19  Sebaceous gland  19.1  Sebaceous gland rudiment. L o n g i t u d i n a l 235 stage  19.2  Sebaceous gland a t 2 6 9 mm section  19*3  Sebaceous gland section  19.^  Sebaceous gland and f o l l i c u l a r f o l d i n a d u l t . Longitudinal section  i n adult  stage,  5 7 57  Longitudinal  . Longitudinal  stage.  opening i n a d u l t .  section...  section.  Longitudinal Longitudinal  5 7 57  6 0 6 0 6 0 6 0  XV  ILEUS TRATIONS  (cont'd)  Figures  Page  20  Arrectoris p i l l i  21  Melanin i n growing h a i r f o l l i c l e  22  Dermis  22.1  Dermis a t e a r l y stage. 202 mm stage  66  22.2  Dermis i n a d u l t  66  23  Epidermis  23.1  Developing  epidermis and dermis. 4-6.2 mm stage  .-23;2  Developing  e p i d e r m i s . Two l a y e r e d stratum  spinosum.  112 mm stage  i n adult material.......  66 66  69  69  23.3  Three l a y e r e d stratum  23.4 24  A d u l t epidermis and p o r t i o n s of dermis S k i n s u r f a c e view. 269 mm stage. Large guard h a i r s emerging  25  S k i n s u r f a c e view. 287 mm stage. guard h a i r s a l s o emerging  26  Fawn b i r t h coat h a i r a r r a y  78  27  Fawn winter coat h a i r a r r a y  78  28  A d u l t summer c o a t . .  28.1  Summer coat h a i r a r r a y  81  28.2  .Close up o f summer coat  81  29  A d u l t w i n t e r coat  29.1  Winter coat h a i r a r r a y  81  29.2  Close up o f winter coat  81  30  Antro p o s t e r i o r d i s t a n c e between s c a l e margins.  spinosum. 181.5 mm stage  Intermediate  A f t e r Spence (1963)  31  H a i r s c a l e arrangement.  32  Deer body r e g i o n s  A f t e r Spence ( I 9 6 3 ) . .  69 69 78 78  83 83  xvi ILLUSTRATIONS  (cont'd)  Figures  Page  32.1  D i f f e r e n t body r e g i o n s of the b l a c k t a i l Side view....  32.2  Head f r o n t view  88  32.3  P o s t e r i o r view of the a n i m a l . . . . . . . . . . . .  88  33  Moult  33.1  Fawn i n b i r t h coat  33.2  Fawn moult stage 1  33.3  Fawn moult stage 2  "  "  "  "  92  33.4  Fawn moult stage 3  •  "  "  "  92  34  Fawn i n w i n t e r coat  92  35  A d u l t i n summer coat  97  36  Moult from a d u l t summer coat t o a d u l t w i n t e r coat.  36.1  Stage 1  97  36.2  Stage 2  97  36.3  Stage  37  A d u l t i n w i n t e r coat  38  Moult from a d u l t w i n t e r coat t o a d u l t coat  38.1  Stage 1  101  38.2  Stage 2  101  38.3  Stage  3  101  39  Photograph  deer.  88  stage  3  92 ( b i r t h t o winter c o a t ) . . . . .  "•'  92  97 101 summer  of t r e p h i n e used f o r b i o p s y 107  sampling 40  F o r t n i g h t l y sampling  41  Deer f o l l i c l e s  4-1.1  Primary f o l l i c l e s  schedule  i n Anagen  107 I l l  (Intermediate guard h a i r s ) . . I l l  xyii  ILLUSTRATIONS (cont»a.) Figures  Page  4-1.2  Secondary f o l l i c l e s  4-2  Intermediate  43  Primary  43.1  Base o f f o l l i c l e  43.2  Close up of the b u l b i n Telogen  4-3.3  Dermal p a p i l l a i n Telogen  43.4  Close up o f s p a t u l a t e dermal p a p i l l a  43.5  New h a i r growing i n r e s t i n g Longitudinal section  I l l  guard h a i r f o l l i c l e  i n catagen.... I l l  f o l l i c l e i n Telogen i n Telogen  I l l I l l 114  follicle.  3114 114  43.6  New h a i r growing i n o l d r e s t i n g Transverse s e c t i o n  4-4  Diagramatic  45  Guard h a i r l e n g t h r e l a t i o n s h i p i n d i f f e r e n t coats of the b l a c k t a i l deer w i t h t h e i r major h a i r c o l o u r zones.....  120  Guard h a i r diameter r e l a t i o n s h i p i n d i f f e r e n t coats of the b l a c k t a i l deer  125  Percentage o f d i f f e r e n t c o l o u r zones i n coat types i n r e l a t i o n t o t o t a l h a i r l e n g t h  129  4-6 4?  follicle.  r e p r e s e n t a t i o n of annual h a i r c y c l e  114 ll6a  48  Percentage o f d i f f e r e n t c o l o u r e d zones I n v i s i b l e p o r t i o n of pelage h a i r , (assumed t o be 10 mm i n winter coat and 20 mm i n summer c o a t ) . 14-4  4-9  Diagram r e p r e s e n t i n g p o s i t i o n of guard h a i r s i n summer coat and w i n t e r coat 14-5  50  Regression l i n e comparing l e n g t h and diameter relationship i n : a) Fawn spotted r e g i o n a g a i n s t fawn non spotted r e g i o n . b) A d u l t winter coat  51 52  14?  H a i r l e n g t h and diameter r e l a t i o n s h i p i n fawn b i r t h coat, i n area other than white spots  148  H a i r l e n g t h and diameter r e l a t i o n s h i p i n fawn b i r t h coat white s p o t t e d r e g i o n  149  xviii  ILLUSTRATIONS  (cont'd)  igures 53  Page H a i r l e n g t h and diameter r e l a t i o n s h i p i n a d u l t w i n t e r coat  150  H a i r l e n g t h and diameter r e l a t i o n s h i p i n a d u l t summer coat  151  55  VJinter coat h a i r l e n g t h and diameter s h i p i n changing h a b i t a t s  I63  56  Artificially  56.1  Plucked f o l l i c l e s regrowing i n underfed a n i m a l . F i r s t week. Ul6 , 166  56.2  P l u c k e d f o l l i c l e s regrowing i n w e l l f e d a n i m a l . F i r s t week. w 4 . . 166  57  W4- i . e . w e l l f e d a n i m a l . H a i r s emerging i n f o u r weeks  5^  58  induced h a i r  relation-  cycle  166  Underfed a n i m a l . Two months a f t e r p l u c k i n g h a i r growth i s a c t i v e  166  59  W e l l f e d animal i n w i n t e r pelage  169  60  Underfed animal i n w i n t e r pelage  169  61 62  H a i r s grow f a s t e r a t s i t e s of sampling i n deer. 169 Winter coat guard h a i r l e n g t h and diameter r e l a t i o n s h i p i n w e l l f e d animal 170  63  Winter coat guard h a i r l e n g t h and diameter r e l a t i o n s h i p i n underfed animal  171  64  R e g r e s s i o n l i n e comparing l e n g t h and diameter r e l a t i o n s h i p between w e l l f e d and underfed w i n t e r coat guard h a i r samples  172  Chapter I GENERAL INTRODUCTION Introduction H a i r s a r e an important mammalian c h a r a c t e r i s t i c . mammals possess them i n v a r y i n g degrees.  All  They are produced i n  the h a i r f o l l i c l e by c e l l s of epidermal o r i g i n . The most important f u n c t i o n performed by pelage appears t o be a s s i s t i n g the animal t o m a i n t a i n a thermal e q u i l i b r i u m and to overcome r i g o u r s of c l i m a t i c f l u c t u a t i o n s Hart  1 9 5 6 ) .  (Scholander et a l 1 9 5 0 ,  The h a i r type c o n s t i t u t i n g the pelage, h e l p t o t r a p  a c u s h i o n of a i r and b u i l d up a thermal g r a d i e n t from s k i n to the outer environment (Ling  I 9 6 5 K  Mammals i n h a b i t a t i n g c o l d e r  r e g i o n s possess c h a r a c t e r i s t i c a l l y t h i c k pelage as opposed t o those o c c u r r i n g i n warmer r e g i o n s .  The t h i c k pelage so advanta-  geous i n w i n t e r i s a disadvantage d u r i n g warm seasons, even i n colder regions.  To o b v i a t e t h i s d i f f i c u l t y mammals moult and the  pelage d i f f e r s between c o l d and hot The  seasons.  i n d i v i d u a l h a i r c o n s t i t u t i n g the pelage may  d i f f e r e n t l y a l o n g t h e i r l e n g t h and t o g e t h e r l e n d c o l o u r a t i o n t o the p e l a g e .  be c o l o u r e d  characteristic  G e n e r a l l y the c o l o u r a t i o n i s darker  i n w i n t e r and l i g h t e r i n summer. The pelage i s a l s o made use of i n the animals behaviour problem and d i s p l a y s ; e.g. Cowan and G e i s t  ( 1 9 6 1 ) ,  and  Geist  ( 1 9 6 6 ) .  I n a d d i t i o n pelage i s r e s p o n s i b l e f o r p r o t e c t i n g the animal from a b r a s i o n and e x t e r n a l damage. as an e f f e c t i v e water p r o o f i n g agent  I n many s p e c i e s i t a l s o a c t s (Flesch  1 9 5 ^ ) •  2  These a t t r i b u t e s i n themselves a r e s u f f i c i e n t t o j u s t i f y i n v e s t i g a t i o n s of pelage from p h y s i o l o g i c a l , a n a t o m i c a l , and e t h o l o g i c a l p o i n t of view.  U n f o r t u n a t e l y to t h i s date r e l a t i v e l y  few mammalian s p e c i e s have been i n v e s t i g a t e d .  B a s i c a l l y the  f o l l o w i n g have been the o b j e c t s of r e s e a r c h , and the t o p i c s  inves-  t i g a t e d range from f o l l i c l e development, morphology, t o annual h a i r c y c l e s and m o u l t i n g . 1 . Humans M e d i c a l determatology has covered the f i e l d  of human h a i r  growth and r e l a t e d phenomena w e l l , c o r r o b o r a t i v e o b s e r v a t i o n a l and experimental evidence has been o b t a i n e d through work on l a b o r a t o r y animals l i k e mice, r a t s and r a b b i t s , e.g. Montagna ( 1 9 5 D ,  Praser 2.  Chase ( 1 9 5 * 0 . ( 1 9 5 ^ ,  1 9 5 5 ) ,  Collins Dry  Dawson  ( 1 9 1 8 ) ,  ( 1 9 2 6 ) ,  ( 1 9 5 6 ) ,  ( 1 9 3 0 ) ,  Butcher  Hay and  etc.  Domestic animals of economic Importance a) Sheep Since t h e i r wool i s of commercial s i g n i f i c a n c e , the phenome-  non of wool p r o d u c t i o n has been looked a t i n some d e t a i l , e.g. F r a s e r and Short Hardy and Lyne 1 9 2 9 ) ,  ( 1 9 3 2 ,  ( I 9 6 0 ) ,  ( 1 9 5 6 ) ,  Auber  Carter  Duerden and W h i t n a l l 1 9 5 7 ) ,  ( 1 9 5 2 ) ,  ( 1 9 3 9 ,  ( 1 9 3 0 ) ,  C a r t e r and C l a r k e  1 9 ^ 3 .  Ryder  1 9 5 5 ) ,  ( 1 9 5 7 ,  ( 1 9 5 7 ) ,  Duerden 1 9 5 8 ) ,  ( 1 9 2 7 ,  Wildman  etc.  b) C a t t l e The s k i n and pelage of c a t t l e have been i n v e s t i g a t e d t o some extent, p a r t i c u l a r l y because of i t s importance i n determining s u i t a b i l i t y f o r I n t r o d u c t i o n of temperate zone c a t t l e i n t o areas  3  of hot c l i m a t e , and a l s o t o a r r i v e a t h y b r i d s  more s u i t e d t o new  environments,  e.g. C a r t e r and Dowllng ( 1 9 5 * 0 *  Dowling  1 9 5 8 ,  ( 1 9 5 ^ ,  ( 1 9 5 5 ,  1 9 5 5 ) ,  ( I 9 6 0 ) ,  and 3«  1 9 5 9 ) .  Dowling  ( I 9 6 0 ) ,  Nay and Hayman  burner  ( i 9 6 0 ) .  Bonsma  ( 1 9 6 3 ) .  tance.  Hayman and Nay  Yeates, N.T.M.  Schleger  ( 1 9 6 l ) ,  Most o f the work has been done i n A u s t r a l i a . pelts  p e l t s of these mammalian types a r e of commercial impor-  The phenomenon of h a i r growth has been i n v e s t i g a t e d t o  some extent i n the f o l l o w i n g s p e c i e s , c h i l l a , Dolnick Ling  ( 1 9 2 0 ) ,  Dowllng and Nay  ( 1 9 5 6 ) ,  Animals w i t h economically v a l u a b l e The  195*0,  (19**3.  Hayman  Camek  ( 1 9 6 5 )  ( 1 9 5 6 )  e.g. Lyne  on mink, S c h e f f e r  ( 1 9 5 6 )  ( 1 9 6 l ) ,  Rand  on c h i n ( 1 9 5 6 ) ,  on s e a l .  As r e g a r d s the r e s t of mammals v e r y l i t t l e  I s known.  From  what l i t e r a t u r e i s a v a i l a b l e the f o l l o w i n g a r e I n t e r e s t i n g , De M e i j e r The has  ( 1 9 5 7 ) .  Carter  ( 1 9 6 5 ) .  knowledge gained on the b i o l o g y of s k i n and h a i r growth,  been the s u b j e c t  Hamilton and  (189*0, Lyne  (1951).  Champion  of s e v e r a l reviews i n books, n o t a b l y  Montagna  ( 1 9 6 2 ) ,  ( 1 9 5 6 ) ,  Montagna and E l l i s  Lyne and Short  ( 1 9 6 5 ) ,  Rothman  those o f  ( 1 9 5 8 ) ,  Rook  (195*0.  Admittedly many of the c o n t r i b u t o r s t o the above l e a n h e a v i l y on d a t a from m e d i c a l dermatology — none the l e s s they a r e of relevance  i n understanding s k i n and h a i r growth of mammals i n  general. Studies  on morphology of h a i r s a r e a l s o Important.  Hairs  themselves present c h a r a c t e r i s t i c s of s c u t e l a t i o n , i n t e r n a l s t r u c t u r e and pigmentation t h a t permit the I d e n t i f i c a t i o n of many mammalian h i g h e r taxa by t h i s means a l o n e . t i o n s i n t h i s respect  a r e from Wildman  Important  (195*1-).  contribu-  Appleyard  ( i 9 6 0 ) ,  Spence (1963). Mayer (19^9), S t a i n s (1958), and Day  (1965).  Apart from such s t u d i e s of the h a i r f i b r e i t s e l f l i t t l e i s known about the c h a r a c t e r i s t i c s of the s k i n , pelage, and  pelage  c y c l e of w i l d s p e c i e s . The present study i s an attempt  t o p r o v i d e i n f o r m a t i o n on  these a s p e c t s of the b i o l o g y of a s i n g l e s p e c i e s of the l a r g e d i v e r s e and w i d e l y d i s t r i b u t e d f a m i l y of ungulates — the cervidae, f o r which no d e t a i l e d i n f o r m a t i o n i s a v a i l a b l e .  5 Chapter  II  THE CERVID PELAGE E x i s t i n g d e s c r i p t i o n s of c e r v l d pelage are g e n e r a l and are more of use i n i d e n t i f i c a t i o n and d e s c r i p t i o n of the a n i m a l . Consequently many important f a c e t s have been overlooked.  We  have  v e r y l i m i t e d i n f o r m a t i o n on the types of h a i r s c o n s t i t u t i n g the c e r v i d pelage, t h e i r i n d i v i d u a l growth c y c l e s , the p a t t e r n s of moult, and the f o l l i c l e s i n which these h a i r s a r i s e .  We  also  have l i t t l e i n f o r m a t i o n on the p h y l o g e n e t i c , a d a p t i v e and behavi o u r a l s i g n i f a n c e of the p e l a g e .  We  do not know a n y t h i n g  d e f i n i t e about the e f f e c t of environmental f a c t o r s of the c e r v i d pelage. Caton  (I877) appears t o be the f i r s t author t o d e s c r i b e a t  some l e n g t h the pelage c h a r a c t e r i s t i c s and t r e n d s of moult i n North American c e r v l d s . Lydekker  (I898) d e a l t w i t h the c e r v i d genera of the world  I n c l u d i n g a g e n e r a l d e s c r i p t i o n of the pelage.  In introductory  pages however t h e r e i s an i n t e r e s t i n g d i s c u s s i o n of i t s a d a p t i v e and b e h a v i o u r a l l y s i g n i f i c a n t f e a t u r e s . P e t e r s o n (1955) i  n  Murie  (1951) and  t h e i r works on e l k and moose r e s p e c t i v e l y  touch upon some pelage c h a r a c t e r i s t i c s and a s p e c t s of moult. L l n s d a l e and Tomich (1953) a l s o r e f e r t o the coat and moult chara c t e r s of the mule deer.  They mention c o l o u r a t i o n and moult  trends. Severinghaus  and Chaetum i n T a y l o r (1956), d i s c u s s a d u l t  coat and moult i n the white t a i l e d deer — and quote  i n d e t a i l from Caton  (I877).  Odocolleus v l r g l n l a n u s  In the same volume mate-  r i a l r e l a t i n g to the Columbian b l a c k t a i l deer Odocolleus hemlonus  6 columblanus  (Richardson),  i s c o n t r i b u t e d by Cowan (1956); who  o f f e r s a s u c c i n c t summary o f pelage f e a t u r e s and moult. Apart  from Lydekker  (I898) the only other a u t h o r i t a t i v e  c o n t r i b u t i o n d e a l i n g w i t h c e r v i d forms over the world i s by Plerov  (i960).  Here the emphasis i s more on the p a l a e a r c t i c  forms; the m a t e r i a l on North American forms being The  s a l i e n t f e a t u r e s of c e r v i d pelage as they emerge from  the above c o n t r i b u t i o n s can be b r i e f l y The  scanty.  summarized as f o l l o w s :  h a i r s on the body vary i n l e n g t h .  s i d e a r e normally  longer  Those on the d o r s a l  than those on the v e n t r a l s i d e .  Simi-  l a r l y there i s an i n c r e a s e i n l e n g t h from a n t e r i o r t o p o s t e r i o r . Some r e g i o n s o f the body bear s p e c i a l i z e d h a i r s .  In general h a i r s  i n the a x i l l a , lnguinum, rump and t a l l a r e l o n g e r whereas those on f a c e , e a r s , and e x t r e m i t i e s o f l e g s a r e s h o r t e r .  A l s o h a i r s on  the under p a r t a r e s o f t e r and p a l e r than those on the exposed body s u r f a c e . The coat.  pelage g e n e r a l l y c o n s i s t s of an overcoat  The overcoat  i s made of h a i r s which a r e longer and t h i c k e r  than those o f the undercoat.  They have c h a r a c t e r i s t i c  a t i o n — a n d t h e i r d i s t a l extremity  The guard h a i r s c o n s t i t u t e  and the bulk o f the pelage.  l i k e Dama Elaphorus,  colour-  i s mostly r e s p o n s i b l e f o r  g i v i n g the animal i t s c o l o u r a t i o n . the outercoat  and an under-  I n c e r t a i n c e r v i d forms  Capreolus ( F l e r o v i 9 6 0 ) , a s p e c i a l type of  guard h a i r — o c c u r r i n g u n i f o r m l y  s c a t t e r e d over the body about  2.5 cms. a p a r t — and having almost double the l e n g t h of normal guard h a i r s — h a s been r e c o r d e d . The  These may be t a c t i l e i n f u n c t i o n *  undercoat c o n s i s t s of woolly  h a i r s , which a r e wavy,  s m a l l e r I n diameter r e a c h i n g on m a t u r i t y about three f o u r t h s of  7 the l e n g t h o f guard h a i r s .  These a r e not v i s i b l e e x t e r n a l l y and  are present i n b u l k o n l y i n c e r v i d w i n t e r c o a t . Busa and sub-genus Przewalskium winter coat  (Flerov i 9 6 0 ) .  However i n genus  these h a i r s a r e absent i n the  The s i g n i f i c a n c e of t h i s i s d i s c u s s e d  subsequently. In the course of the year the c e r v i d pelage has two phases. The  summer phase i s of l i g h t e r c o l o u r and marked by s c a r c i t y of  w o o l l y under h a i r s .  The w i n t e r phase i s darker c o l o u r e d and has  an abundance o f w o o l l y under h a i r s . The  change over from one phase Into the other i s brought  about by a process o f m o u l t i n g , i n v o l v i n g shedding o f o l d h a i r s accompanied by growth of new h a i r s .  F l e r o v (i960) d i s c u s s e s  a s p e c t s of t h i s process i n some d e t a i l . The  two main f e a t u r e s i n the e v o l u t i o n of c e r v i d  pelage  t h a t a t t r a c t immediate a t t e n t i o n a r e : 1)  P r i m i t i v e forms w i t h s p o t t e d pelage t h a t i n the advanced forms occurs o n l y i n the newborn or not a t a l l .  2)  E v o l u t i o n o f a w i n t e r coat s p e c i f i c a l l y adapted r i g o u r s o f c o l d environment.  t o meet  These w i l l be c o n s i d e r e d i n t h e i r r e s p e c t i v e o r d e r . The value.  s p o t t e d nature o f the coat i s s a i d t o be of p r o t e c t i v e  By h e l p i n g t o break up the body o u t l i n e i t merges the  animal w i t h the p a t t e r n s o f l i g h t as they e x i s t i n f o r e s t s , and e f f e c t i v e l y conceals i t . The  s p o t t e d coat i s present throughout  the l i f e of c e r t a i n  c e r v i d forms e.g. A x i s a x i s , or i t may be present o n l y i n the fawn b i r t h coat and a d u l t summer c o a t — being v e r y weak or absent i n the a d u l t w i n t e r c o a t . e.g. Cervus nlppon the Japanese S i k a deer.  I n the r e l a t i v e l y r e c e n t forms l i k e Odoooileus  the spots  8 a r e r e t a i n e d o n l y i n b i r t h c o a t , Caton (I878) however r e f e r s t o f a i n t spots e x h i b i t e d i n summer c o a t of some Odooolleus nus forms.  Virginia:-  Cowan (1965) s t a t e s t h a t o n l y the fawn " b l a c k t a i l " O  are s p o t t e d and t h a t these spots disappear w i t h l o s s o f the fawns h i d i n g i n s t i n c t i n the f i e l d .  A l s o r e c e n t forms l i k e Cervus  canadensis and A l e e a l c e s have fawns and a d u l t s devoid of any spots on the p e l a g e .  There i s thus a d e f i n i t e e v o l u t i o n a r y t r e n d  towards l o s s o f spots, the r e a s o n f o r which i s not c l e a r . The It  e v o l u t i o n of a t h i c k w i n t e r coat i s a l s o  i s g e n e r a l l y assumed t h a t deer f i r s t  f o r e s t s and possessed a brownish c e r v i d summer c o a t .  evolved i n warm t r o p i c a l  coat e q u i v a l e n t of present day  T h i s coat, i n a d d i t i o n , was s p o t t e d a l o n g  the f l a n k s , Lydekker (I898). r e m i n i s c e n t of i t .  interesting.  The present day summer coat i s  With the g r a d u a l spread of c e r v i d forms t o  areas o f c o l d e r c l i m a t e t h e need f o r a w i n t e r coat arose and f a c t o r s l e a d i n g towards i t appear t o have been s e l e c t e d f o r , these c o n s i s t of development of w o o l l y undercoat and t h i c k e r hairs.  Such a heavy coat however i s a l i a b i l i t y  guard  i n summer and  thus the process o f moulting twice a year has been s e l e c t e d f o r by which a p p r o p r i a t e c o a t s (summer and w i n t e r ) a r e assumed d u r i n g 0  the course of the year I n consonance w i t h the season. The  sub genus Przewalsklum  a c e r v i n e form o c c u r r i n g i n c o l d  Tibetan highlands i s i n t e r e s t i n g i n t h i s respect.  Though i t  possesses a w i n t e r and summer c o a t , i t s w i n t e r coat i s devoid of w o o l l y u n d e r h a i r F l e r o v (i960).  Instead i t s w i n t e r c o a t i s con-  s t i t u t e d of h a i r s which a r e l o n g and twice as t h i c k as the summer hairs. to  There a r e thus a t l e a s t two d i f f e r e n t e v o l u t i o n a r y r o u t e s  development o f w i n t e r adapted  pelage.  9 When only one type o f coat was present presumably the moult ing  took p l a c e o n l y once a year r e p l a c i n g a coat a f f e c t e d by  normal wear and t e a r d u r i n g the y e a r . two moults a year were n e c e s s a r y .  With two types of coat  —  Males g e n e r a l l y a r e f i r s t t o  moult and fawns and unbred females f o l l o w . g e n e r a l l y moult a month or so l a t e r .  Females w i t h fawn  Sufficiently detailed  matlon on c e r v i d p a t t e r n s of moult i s n o t a v a i l a b l e —  infor  nor the  sequence i n which v a r i o u s h a i r types a r e shed. F l e r o v (I960) a l s o r e f e r s t o the occurrence of whorls i n pelage o f many c e r v i d form e.g. Przewalsklum, E l a p h o r u s , Dama, Mazama, e t c . The s e l e c t i o n value o f these s t r u c t u r a l o d d i t i e s i s n o t clear.  Parnell  ( 1 9 5 1 ) d i s c u s s e s the b a s i s f o r these whorls i n  two main t y p e s . a) " f a c t o r s i n f l u e n c i n g growth of embryo such as t e n s i o n and p r e s s u r e of t h i n s u r f a c e , i t s t h i c k n e s s and pressure or absence o f the s t r u c t u r e beneath i t " . b) " i n t r i n s i c f a c t o r s i n growing h a i r germ such as a p h y s i o l o g i c a l g r a d i e n t or i n the g e n e t i c a l make up of the i n d i v i d u a l " . B e h a v i o u r a l l y c e r v i d pelage p r e s e n t s i n t e r e s t i n g  features.  The i n c r e a s e d growth o f h a i r on the neck l e a d i n g , t o the format i o n o f a mane, p a r t i c u l a r l y i n b r e e d i n g season, i s b e l i e v e d t o be o f p r o t e c t i v e and d i s p l a y v a l u e , as a t t h i s time combats a r e frequent. The u n d e r s i d e of the t a i l , as w e l l as the p o s t e r i o r margin of  t h i g h s i s g e n e r a l l y white (Odocolleus, A x i s ) .  When e x c i t e d  as when f l e e i n g , such forms r a i s e t h e i r t a i l s , and i t s white underside i n c o n j u n c t i o n w i t h white p o s t e r i o r margins of t h i g h forms a v e r y n o t i c e a b l e white a r e a — e n a b l i n g animals t o f o l l o w  10  each o t h e r . are  erectile.  I n A x i s and Odocolleus the white h a i r s of t h i s r e g i o n I n forms l i k e Capreolus and Cervus, a white rump  patch i s formed; In  f o r Capreolus t h i s i s o n l y i n the w i n t e r c o a t .  s p e c i e s h a v i n g a rump p a t c h the t a i l i s reduced and i s not  r a i s e d when the animals a r e e x c i t e d or f l e e i n g . The h a i r s surrounding the t a r s a l and m e t a t a r s a l glands a r e much c o a r s e r than the a d j o i n i n g h a i r s and a r e capable of e r e c t i o n . Though n o t a p a r t o f the pelage the ' v e l v e t * c o v e r i n g the a n t l e r s o f deer i s a l s o o f g r e a t i n t e r e s t .  I t bears s h o r t and  s o f t h a i r s a r i s i n g i n f o l l i c l e s which l a c k the sweat g l a n d and the A. p l l i i muscle.  When the a n t l e r s mature the v e l v e t becomes  n e c r o t i c and i s shed; o n l y t o be formed a g a i n »de novo' t o cover a new s e t of growing a n t l e r s , the f o l l o w i n g y e a r .  T h i s i s the  only case of h a i r f o l l i c l e neogenesis i n a d u l t mammals supported by i r r e f u t a b l e evidence, B l l l i n g h a m ( 1 9 5 8 ) .  11 Chapter I I I PRENATAL DEVELOPMENT OF THE PILARY SYSTEM IN DEER  INTRODUCTION Though i n t e r e s t i n the g e n e r a l phenomenon of h a i r growth i s i n c r e a s i n g , o b s e r v a t i o n s on p r e n a t a l development of h a i r are of  r e l a t e d s t r u c t u r e s c o n t i n u e s t o be l i m i t e d .  follicles  Known examples  s i g n i f i c a n t work done i n the f i e l d are guinea p i g , ( S e a g a l l  1 9 1 8 ) ; mouse,(Hardy, 1 9 ^ 9 ) ; bandicoot (Lyne, 1 9 5 7 ) ; mink ( D o l n i c k 1959); c a t t l e  (Lyne and Heideman, 1959.  and Hardy and Lyne, 1 9 5 6 ) ; goat seal  (Ling, 1965).  I960);  sheep (Wildman, 1932  (Margolena, 1 9 5 9 ) ; and elephant  I n g e n e r a l these workers have t r a c e d the  development of h a i r f o l l i c l e s and suggested boundaries and of a u s e f u l approach  criteria  t o s t a n d a r d i z e stages, In the continuous  process. No study of f o l l i c l e development appears t o have been made i n wild ungulates.  The p r e s e n t work r e p o r t s the course of d e v e l -  opment of the p i l a r y system i n the b l a c k t a i l deer Odocolleus hemionus columbianus  (Richardson), a North American  cervid,  thus p r o v i d e s f o r the f i r s t time a b a s i s f o r comparison two of the major f a m i l i e s of the a r t i o d a c t y l a —  and  between  the c e r v i d a e and  the bovidae.  MATERIALS AND  METHODS  T h i s study i s based upon a s e r i e s of f o e t u s e s taken from w i l d does c o l l e c t e d i n the course of a study of r e p r o d u c t i o n i n this species.  P r e s e r v a t i o n was  i n formol s a l i n e .  12  TABLE 1 B a s i c Data on Foetuses Sampled Foetus  Date  Forehead Rump  Numbers* T80  A M*  Length  (mm)  Jan.  65  46.2  29 Jan.  64  89.5  64  112.5  15  T27  p#  T36  p#  T4-1  A M*  19 March 64  181.5  T46  B  M*  22 March 64  202.0  64  211.5  Mar ch 64  235.0  M*  T5^  T40 A M*  l  T82  6 May1 8  7 May  6k  236.0  p*  8 A p r i l 63  269.0  M*  16 A p r i l 66  287.0  T56 A M* M  3 Feb.  T63 A F*  11  May  6^  3 2 1 . 0-L  T60  M*  11  May  64  335.0  T66  p#  13 May  64  366.0  T69  M*  12 June  64  4-22.0  T70 A M*  12 June  64  438  B  *f=  Female  *m=  Male  mm  13 F i f t e e n r e p r e s e n t a t i v e f o e t u s e s each of a d i f f e r e n t opmental stage were s e l e c t e d f o r sampling purposes.  devel-  A l l but one  (M]_) were from Northwest Bay, Vancouver I s l a n d , B.C.  i.e.  samples were taken from each a t predetermined l o c a t i o n s ,  Skin dorsally  on the base o f the neck. The m a t e r i a l so obtained was h i s t o l o g i c a l l y processed (see Appendix I ) and 8  t h i c k s e c t i o n s were c u t p a r a l l e l t o the s k i n  s u r f a c e as w e l l as a c r o s s i t .  These were s t a i n e d i n Haematoxylin  and E o s l n and used f o r f u r t h e r  observations.  OBSERVATIONS The development o f h a i r f o l l i c l e s  c a n be s t u d i e d i n two  main a s p e c t s namely the development o f the i n d i v i d u a l h a i r cle In  —  folli-  and the development of the f o l l i c l e groups and p o p u l a t i o n .  the u n g u l a t e s i n v e s t i g a t i o n s of t h i s aspect appear t o be  r e s t r i c t e d t o sheep and c a t t l e . Wildman (1932) has d i s c u s s e d the p r e n a t a l development of a wool f o l l i c l e Lyne  i n some of the B r i t i s h breeds of sheep.  (1956)have c h a r t e d development of merino f o l l i c l e s  Hardy and and p r o -  posed r e c o g n i t i o n o f e i g h t developmental stages, the f i n a l  stage  of which i s reached when the h a i r emerges on the s k i n s u r f a c e . Lyne and Heideman (1959) i n course o f t h e i r work on f o l l i c l e development i n c a t t l e have proposed t e n stages r a t h e r than e i g h t , the  final  stage being reached when the h a i r growth ceases and the  f o l l i c l e rests.  These stages o f f o l l i c l e development have proved  a p p l i c a b l e t o those s p e c i e s i n v e s t i g a t e d t o date and p r o v i d e a u s e f u l framework f o r the study o f other s p e c i e s . s t a t e d as f o l l o w s  (Fig.  1)  They can be  Ih  K E R A T I N I Z E D  H A I R  M E D U L L A  mA  I N N E R  R O O T  S E B A C E O U S P R E - P A P I L L A  FIG. I  S T A G E S I TO 10 IN T H E DEVELOPMENT OF MAMMALIAN HAIR FOLLICLES AS SHOWN IN C A T T L E AFTER  LYNE  AND HE IDEMAN  (1959)  S H E A T H C E L L S  Stage I .  Follicle  plug  T h i s i s d i v i d e d i n t o two  stages.  a) when l e n g t h of p l u g i s l e s s than i t s diameter. b) when l e n g t h i s e q u a l t o or g r e a t e r than diameter. Stage 2.  Pre - p a p i l l a a) F o l l i c l e l e n g t h more than twice i t s diameter, the base of epidermal plug f l a t t e n e d , sweat g l a n d appears a t h i g h e r l e v e l s of f o l l i c l e i n form of a s o l i d bud l o c a t e d on e n t a l s i d e . b) F i r s t t r a c e of a r r e c t o r p i l i i muscle now appears i n dermis; A s w e l l i n g i s a l s o n o t i c e d halfway down on e n t a l s i d e of f o l l i c l e . T h i s i s the e n t a l s w e l l i n g . Sebaceous c e l l s b e g i n to d i f f e r e n t i a t e below j u n c t i o n of sweat g l a n d and c o n s t i t u t e rudiments of sebaceous g l a n d . F i r s t stages of h a i r c a n a l f o r m a t i o n noticed.  Stage 3.  Papilla  The d i f f e r e n t i a t i o n of sub stages here i s based on the shape of the dermal p a p i l l a . a) F o l l i c l e base becomes concave and dermal p a p i l l a i s g r e a t e r i n diameter than i n depth. A r r e c t o r p i l i i muscle extends from upper p a r t of dermis up t o e n t a l s w e l l i n g . H a i r c a n a l f o r m a t i o n i s noted. Sweat g l a n d has now reached i n depth the r e g i o n between e n t a l s w e l l i n g and b u l b of f o l l i c l e , and c o n t a i n s a lumen a t i t s d i s t a l end. b) Length of dermal p a p i l l a equal or g r e a t e r than i t s diameter. E n t a l s w e l l i n g has reached maximum s i z e and h a i r c a n a l development i s almost complete and i t s p a r t i n epidermis i s l y i n g almost p a r a l l e l t o skin surface. Stage 4 .  H a i r cone The e n t a l s w e l l i n g now becomes a l i t t l e  prominent and the deeper end of the f o l l i c l e of  a hair  cone.  less  e x h i b i t s the presence  Stage  5•  Advanced h a i r cone The t i p of h a i r cone Is r e t r a c t i l e .  Stage  6.  Hair formation H a i r cone l i e s a t about l e v e l of sebaceous gland. Hair t i p i s k e r a t i n i s e d . A l l f o l l i c l e l a y e r s are by now formed.  Stage  7.  H a i r In c a n a l Tip  Stage  8.  of the h a i r has emerged i n t o h a i r c a n a l .  H a i r emerged H a i r has emerged on s u r f a c e .  Stage  9 • End of f o l l i c l e Follicle  Stage 10.  growth  reaches i t s maximum growth.  Club h a i r formation a) Bulb c o n t r a c t s and c o n n e c t i v e t i s s u e around i t gets c r i n k l e d . b) Club h a i r f o r m u l a t i o n w i t h t y p i c a l end i s f i r s t r e c o g n i s e d .  brush  c) Club h a i r i s k e r a t i n i s e d i n f u l l . In  stage t e n the f o r m a t i o n of the medulla comes to an  end  f o l l o w e d l a t e r by the h a i r c u t i c l e and the i n n e r r o o t sheath. The f o l l i c l e  i s s i m u l t a n e o u s l y d e c r e a s i n g i n l e n g t h and the b u l b  and dermal p a p i l l a undergo d e g e n e r a t i o n t i l l resemble  they somewhat  t h e i r morphology i n stage t h r e e .  I t must be n o t i c e d t h a t these stages r e f e r t o the d e v e l opment of i n d i v i d u a l h a i r f o l l i c l e s  and not the f o l l i c l e  popula-  tion. All  the above stages, can be i d e n t i f i e d i n the sequence of  development of f o l l i c l e s t i o n s and these w i l l  i n Odocolleus.  be d e t a i l e d  There a r e minor v a r i a -  later.  Another aspect of f o l l i c l e development i s t h a t of the o r i g i n of groups and p o p u l a t i o n s of f o l l i c l e s .  Different  1 7  c a t e g o r i e s o f f o l l i c l e s a r i s e t h a t g i v e o r i g i n t o h a i r s of d i s t i n c t types.  Furthermore  the arrangement and spacing of f o l l i -  c l e s p r e s e n t f e a t u r e s t h a t may be of importance of  i n the e l u c i d a t i o n  s y s t e m a t i c p o s i t i o n s or e c o l o g i c a l a d a p t a t i o n . De M e i j e r e  (189*0  was one of the f i r s t t o i n v e s t i g a t e  arrangement of h a i r f o l l i c l e s and the h a i r a r i s i n g i n them. H i s work stands out as a p i o n e e r i n g c l a s s i c of i t s k i n d , i n which he brought out the f a c t t h a t b a s i c a l l y the f i r s t formed  follicles  i n mammals a r e arranged i n groups of t h r e e of which the c e n t r a l f o l l i c l e i s l a r g e r than the two f o l l i c l e s l y i n g l a t e r a l t o i t . The h a i r f o l l i c l e s have a l s o been c l a s s i f i e d i n r e l a t i o n to  t h e i r sequence o f o r i g i n and development.  Noback  has  ( 1 9 5 1 )  d i s c u s s e d t h i s s u c c i n c t l y as f o l l o w s : "The f i r s t f o l l i c l e s trio follicles.  t o d i f f e r e n t i a t e a r e the c e n t r a l  I f these f o l l i c l e s appear a t two d i f f e r e n t  as i n opossum (Gibbs  1 9 3 8 ) ,  "primary X" and "primary Y".  times  then the f o l l i c l e s a r e c a l l e d The e s s e n t i a l p o i n t i s t h a t each of  these primary f o l l i c l e s w i l l be the c e n t r a l f o l l i c l e s o f d i f f e r e n t groups.  L a t e r i n development other f o l l i c l e s o f the h a i r  group  d i f f e r e n t i a t e i n r e l a t i o n t o these c e n t r a l t r i o f o l l i c l e s .  The  t r i o i s formed when two f o l l i c l e s a r e d i f f e r e n t i a t e d l a t e r a l t o the primary f o l l i c l e s .  The l a t e r a l f o l l i c l e s a s s o c i a t e d w i t h  "primary x " or "primary Y" a r e c a l l e d r e s p e c t i v e l y "primary 3£ or primary Y " .  I f o n l y one l a t e r a l f o l l i c l e i s formed a d j a c e n t t o a  primary f o l l i c l e  (X or Y) then a c o u p l e t f o l l i c l e i s formed.  no l a t e r a l f o l l i c l e s d i f f e r e n t i a t e a primary solitary f o l l i c l e .  If  (X or Y) i s c a l l e d  L a t e r another g e n e r a t i o n o f f o l l i c l e s i s  d i f f e r e n t i a t e d — the secondary f o l l i c l e s .  I n the opossum these  f o l l i c l e s a r e l o c a t e d between the c e n t r a l t r i o f o l l i c l e and the  18 lateral trio  follicle.  The ontogenetic s t u d i e s o f f o l l i c l e  arrangement have added c o n f i r m a t o r y evidence b a s i c concept  t h a t i n mammals there i s a u n i v e r s a l and r e g u l a r (Hardy 1 9 4 - 6 ) " .  grouping o f h a i r f o l l i c l e s . Follicle  t o De M e i j e r e ' s  and H a i r development  The h a i r f o l l i c l e s  o f the b l a c k t a i l deer can be d i v i d e d on  the b a s i s of t h e i r o r i g i n i n t o two types — secondary.  The p r i m a r i e s a r e the f i r s t t o form and develop i n  groups o f three the t r i o  the primary and the  (trio  grouping), o f these the c e n t r a l f o l l i c l e o f  i s the f i r s t t o form — a n d I s a k i n t o "primary X".  The  l a t e r formed p r i m a r i e s which form the two l a t e r a l f o l l i c l e s of trio  grouping a r e a k i n t o "primary X" o f Noback ( 1 9 5 1 ) •  no occurrence o f "primary types.  *Y'" f o l l i c l e s  There i s  nor any o f 'primary Y'  Each of the p r i m a r i e s possesses a sweat gland, sebaceous  gland and a r r e c t o r p l l i l muscle.  I n c o n t r a s t t o the p r i m a r i e s  which s t a r t d e v e l o p i n g around 112 mm. c l e s b e g i n d e v e l o p i n g around 2 6 9 mm.  stage, the secondary stage.  The secondary  follifolli-  c l e s a r e much s m a l l e r than the p r i m a r i e s and a r e l o c a t e d I n groups between the p r i m a r i e s .  The f i r s t formed secondaries a r e  l a r g e r than those subsequently  formed and possess  sebaceous gland and a r r e c t o r p i l l i muscle.  sweat gland,  The r e s t o f the  s e c o n d a r i e s bear only sebaceous gland and the s m a l l e r of them may even l a c k these. The f o l l i c l e  types bear a c l o s e r e l a t i o n s h i p t o the h a i r s  t h a t a r e produced i n them.  We know t h a t the b l a c k t a i l  c o n s i s t s o f an overcoat and a w o o l l y undercoat developed  during winter.  pelage  which i s w e l l  The overcoat c o n s i s t s of h a i r s produced  FIGURE 2 Grouping of primary and secondary f o l l i c l e s i n deer. Transverse s e c t i o n . N o t i c e the t y p i c a l ' f i v e ' grouping; o f primary and secondary f o l l i cles. H.& E. FIGURE 3A Deer primary f o l l i c l e . Longitudinal section. General view of the lower end of the f o l l i c l e . Notice w e l l developed medulla. H. & E.  FIGURE 3B Deer secondary f o l l i c l e . Longitudinal s e c t i o n . General view of the lower end o f the follicle. N o t i c e h y a l i n e membrane on both s i d e s of e x t . r o o t h sheath and absence o f the medulla. H. & E.  FIGURE 4.1 Developing s k i n and h a i r f o l l i c l e s . 112 mm. stage. L o n g i t u d i n a l s e c t i o n . N o t i c e the t h i n epidermis and the h a i r f o l l i c l e anlage being formed. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV,' Page 214.  20  21 i n primary f o l l i c l e s . of  Some of these a r e almost double the l e n g t h  the other overcoat h a i r s and a r e s c a t t e r e d on the body about  2.5 cms. a p a r t .  I have r e f e r r e d t o them as the l a r g e guard  hairs.  They a r e produced by some o f the c e n t r a l primary f o l l i c l e s .  The  r e s t o f the c e n t r a l primary f o l l i c l e s and a l l of the l a t e r a l primary f o l l i c l e s hairs.  g i v e r i s e t o what I c a l l i n t e r m e d i a t e guard  These c o n s t i t u t e the r e s t of the o v e r c o a t .  Of course  there i s a good d e a l of v a r i a t i o n i n s i z e of the i n t e r m e d i a t e guard h a i r s but c o n s i s t e n t l y i n a t r i o those produced  i n the  c e n t r a l p r i m a r i e s a r e l a r g e r than those produced by the l a t e r a l primaries.  A l l the h a i r s produced by primary f o l l i c l e s a r e  medullated. The b l a c k t a i l e d fawns a r e c h a r a c t e r i z e d by p o s s e s s i o n o f white spots on t h e i r body.  These a r e formed by the occurrence i n  these s i t e s of h a i r p o s s e s s i n g white d i s t a l e x t r e m i t i e s . h a i r s appear  t o be produced mostly i n c e n t r a l primary  and some i n l a t e r a l p r i m a r i e s .  These  follicles  The white t i p p e d p a r t has a  g r e a t e r development of the c o r t e x and a medulla d e v o i d of i n t r a cellular cavities.  In subsequent  h a i r c y c l e s these h a i r s a r e  r e p l a c e d by normal o u t e r c o a t h a i r s .  T h i s phenomenon by which a  h a i r f o l l i c l e produces one type of h a i r a t one stage and another type a t a d i f f e r e n t stage i s n o t u n u s u a l . t h i s o c c u r r i n g i n some sheep, The  secondary f o l l i c l e s  the undercoat.  Wlldman (1927), r e p o r t s  i n c l u d i n g f i n e wooled  merino.  o f the b l a c k t a i l deer g i v e r i s e t o  T h i s i s not v i s i b l e e x t e r n a l l y but i s w o o l l y and  i s pronouncedly developed i n the animal's w i n t e r c o a t .  It i s  i n t e r e s t i n g and important t o note t h a t the f i r s t formed  secondary  f o l l i c l e s produce medullated h a i r s , whereas the r e s t of the  22  secondaries produce non medullated  hairs.  The bulk o f the under-  coat c o n s i s t s o f the l a t t e r . In the course of t h i s study I have a l s o c l a s s i f i e d on the b a s i s o f h a i r types produced by them. of  t h e i r i n d i v i d u a l development e a s i e r .  follicles  T h i s makes the study  The c l a s s i f i c a t i o n i s as  follows: a) Large guard h a i r f o l l i c l e s . c e n t r a l p r i m a r i e s producing  These a r e some of the  l a r g e guard h a i r s .  b) C e n t r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s . the r e s t o f the c e n t r a l p r i m a r i e s , which produce guard h a i r s .  These a r e  intermediate  The h a i r s produced by them a r e l o n g e r and l a r g e r  than those produced by l a t e r a l i n t e r m e d i a t e guard h a i r i.e.  follicles  l a t e r a l primaries. c) L a t e r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s .  They a r e the  same as the l a t e r a l p r i m a r i e s and produce i n t e r m e d i a t e guard h a i r follicles. d) F i r s t formed secondary f o l l i c l e s . the l a t e r formed and produce medullated l i k e the p r i m a r i e s possess arrector p i l i i  These a r e l a r g e r than  hairs.  These  follicles  sweat gland, sebaceous gland and  muscle.  e) L a t e r formed secondary f o l l i c l e s . Possess only sebaceous glands and produce non medullated  These a r e s m a l l .  (the s m a l l e s t may even l a c k  woolly underhair  these)  — c o n s t i t u t i n g the  bulk of the undercoat. At t h i s stage i t should be noted  t h a t i n the fawn b i r t h  coat some of the c e n t r a l p r i m a r i e s and l a t e r a l p r i m a r i e s g i v e r i s e t o guard h a i r s with white t i p s .  These h a i r s a r e c h a r a c t e r -  i z e d by g r e a t e r t h i c k n e s s o f the c o r t e x , and by p o s s e s s i n g a  23 medulla d e v o i d of i n t r a c e l l u l a r c a v i t i e s , so c h a r a c t e r i s t i c of the medulla of other overcoat h a i r s .  On the other hand the  medullary c e l l s appear t o be f u l l of d r o p l e t s — perhaps  of t r i c h o -  hyaline. The o b s e r v a t i o n s on f o l l i c l e development t h a t I have been a b l e t o make are as f o l l o w s : follicle  The g e n e r a l mammalian stages of  development are n o t i c e d i n the b l a c k t a i l deer.  However  v a r i a t i o n s from the normal have been documented i n a number of places.  0  Large guard h a i r  follicles  These a r e the e a r l i e s t f o l l i c l e s  to develop and can be  i d e n t i f i e d by t h e i r g r e a t e r depth of p e n e t r a t i o n i n t o the Where p r e s e n t they c o n s t i t u t e the c e n t r a l f o l l i c l e trio  grouping.  hairs.  These f o l l i c l e s  a c t i v e l y producing h a i r i n a new r e s t i n g I n a f i v e week fawn.  f o e t u s ; are  born fawn, and are generally-  The e x t e r n a l r o o t sheath i s  w e l l developed and prominently n u c l e a t e d .  The f o l l i c l e b u l b i s  The i n n e r r o o t sheath i s a l s o prominent  u l a r l y the Henle's l a y e r .  Compared t o the s i z e of the  the sebaceous g l a n d i s s m a l l .  follicle  to d i l a t e i n the form of a  bulbous c a v i t y , the l i n i n g of which (made of i n n e r r o o t has a f o l d e d appearance.  — partic-  J u s t below the j u n c t i o n of the  sebaceous g l a n d the f o l l i c l e appears  to  guard  They possess sweat gland, sebaceous  gland, and a r r e c t o r p i l i i muscle.  l a r g e and o v a l .  of the primary  g i v e r i s e to the l a r g e  They are b e g i n n i n g development i n a 112 mm.  dermis.  These " f o l l i c u l a r  sheath)  f o l d s " are supposed  be p a r t of the break down of the i n n e r r o o t sheath and have  a l s o been n o t i c e d i n case of the common amer l e a n goat, Sar  Developing  s k i n and h a i r f o l l i c l e s .  202 mm  stage  FIGURE 5.1 The epidermis has i n c r e a s e d i n s i z e and periderm i s d i s t i n c t . The sweat gland i s d e v e l o p i n g and f o l l i c l e base i s h a l f enveloping the dermal p a p i l l a . The f i b r o u s d e p o s i t i o n i n dermis i s a l s o n o t i c e d . H. & E . FIGURE 5.2 Transverse s e c t i o n of above. N o t i c e sweat gland d e v e l o p i n g a d j o i n i n g the h a i r f o l l i c l e • H. & E. Developing  s k i n and h a i r f o l l i c l e . 235 nun s t a g e . FIGURE  6.1  L o n g i t u d i n a l s e c t i o n . N o t i c e w e l l developed stratum spinosum. Periderm i s p e e l i n g and below i t g r a n u l a r l a y e r (stratum granulosum) i s forming. Sweat g l a n d has no lumen. Sebaceous gland and h a i r c a n a l f o r m a t i o n i s a l s o p r e s e n t . Dermis i s more compact. Rudimentary a r r e c t o r p i l i i development i s seen. H. & E. FIGURE 6.2 Transverse s e c t i o n of above. Sweat gland f o l l i c l e r e l a t i o n s h i p i s seen. H. & E. For e x p l a n a t i o n of a b b r e v a t i o n s used please see Appendix IV, Page 21k%  25  Developing  s k i n and h a i r f o l l i c l e s . 2 6 9 mm FIGURE  stage  7.1  L o n g i t u d i n a l s e c t i o n . N o t i c e the compact epidermis and the d i s t i n c t i v e stratum corneum. Sebaceous gland i s d i s t i n c t i v e so a l s o i t s p o s i t i o n v i s a v i s sweat g l a n d . Dermis more compact and f i b r o u s . E n t a l s w e l l i n g and a r r e c t o r p i l i i muscle p r e s e n t . Hi & E. FIGURE  7.2  Transverse s e c t i o n of above. Large guard h a i r f o l l i c l e d i s t i n c t w i t h h a i r . Sweat gland and b i l o b e d sebaceous gland seen. F i r s t formed s e c o n d a r i e s d e v e l o p i n g . H. & E. Developing  s k i n and h a i r f o l l i c l e s . 28? mm FIGURE  stage.  8.1  L o n g i t u d i n a l s e c t i o n . White t i p p e d h a i r f o l l i c l e s c l e a r l y seen. Secondary f o l l i c l e s forming. H. & E. FIGURE  8.2  Transverse s e c t i o n of above. C e n t r a l p r i m a r i e s have l a r g e r h a i r s than l a t e r a l p r i m a r i e s . H. & E. F o r e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV. Page 214.  27  Developing s k i n and h a i r f o l l i c l e s .  321 mm  stage  FIGURE 9.2 Longitudinal section. Notice s i z e r e l a t i o n s h i p o f c e n t r a l primary t o l a t e r formed second a r i e s s t i l l forming. H. & Et  FIGURE 9.2 Transverse s e c t i o n o f above.  Developing s k i n and h a i r f o l l i c l e s .  H. & E.  448 mm  stage  FIGURE 10.1 Longitudinal section.  General view.  H. & E.  FIGURE 10.2 Transverse s e c t i o n o f above. N o t i c e white t i p p e d h a i r f o l l i c l e s i n s e c t i o n . H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV, Page 214-.  29  Large guard f o l l i c l e .  287 mm  stage  FIGURE 11.1 L o n g i t u d i n a l s e c t i o n . Notice l a r g e s i z e of l a r g e guard h a i r f o l l i c l e v i s a v i s other types and w e l l developed e x t e r n a l r o o t sheath. H. & E.  FIGURE 11.2 Transverse s e c t i o n o f above. arrangement. H. & E.  Notice  follicle  FIGURE 11.3 L o n g i t u d i n a l s e c t i o n . Close up of d i l a t e d upper p a r t o f l a r g e guard h a i r f o l l i c l e and h a i r p a s s i n g through i t . Dermis i s very compact now. H.&E-. FIGURE 11.4 L o n g i t u d i n a l s e c t i o n . Close up of the f o l l i c l e bulb. Notice heavy m e l a n i n , d e p o s i t i o n i n f o l l i c l e and w e l l developed e x t e r n a l r o o t sheath. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s see Appendix IV, Page 214.  used  please  Fib  SwG Ap  FIG It.4  32 and Calhoun  (1966).  I t i s p e r t i n e n t t o remark t h a t the s p e c i e s  s t u d i e d by these authors i s not known as they have used a meaningless  name.  With the e x c e p t i o n o f F l e r o v  (I960), who r e f e r s t o occur-  rence o f l a r g e guard h a i r s i n the c e r v i d genera Dama, Capreolus, and Elaphorus, no r e f e r e n c e has been made t o occurrences o f such h a i r s or the l a r g e guard h a i r f o l l i c l e s i n the u n g u l a t e s . Straile  (i960) d i s c u s s e s the occurrence o f t y l o t r i c h i n mammals  (Mice, Rats and R a b b i t s ) and t h e i r f u n c t i o n .  The t y l o t r i c h s a r e  much l a r g e r than the surrounding guard h a i r s and a r e s p a r s e l y distributed.  They a r e sensory h a i r types a r i s i n g i n f o l l i c l e s  which possess, amongst other t h i n g s , an "Annular complex" c o n s i s t i n g o f c o n n e c t i v e t i s s u e , c a p i l l a r i e s and nerve  endings,  surrounding the f o l l i c l e below the l e v e l of sebaceous  gland.  The  o r i f i c e of the f o l l i c l e i s a l s o c h a r a c t e r i z e d by p o s s e s s i o n of a s p e c i a l t h i c k e n e d a r e a o f the epidermis c a l l e d surrounding the o r i f i c e .  "Baarschlebe"  The t y l o t r i c h f o l l i c l e i s sensory and  i s i n t e r m e d i a t e i n s i z e between the v i b r i s s a f o l l i c l e and the normal h a i r  follicle.  In the l i v i n g a d u l t Odooolleus the l a r g e guard h a i r s a r e s c a t t e r e d over the body and a r e prominently longer than other outercoat h a i r s .  I f they a r e touched i n the l i v i n g animal the  s k i n i s t w i t c h e d i n response. other t y p e s .  T h i s i s not t r u e w i t h the h a i r s o f  Thus the l a r g e guard h a i r f o l l i c l e s appear  f a c i e " t o be possessed of g r e a t e r sensory f u n c t i o n than hairs.  I n Odooolleus they s t a r t development s l i g h t l y  "prima normal  earlier  than other primary f o l l i c l e s but grow t o much g r e a t e r l e n g t h because  of g r e a t e r r a t e of growth d u r i n g the f o l l i c l e  and a l o n g e r h a i r growth p e r i o d .  T h e i r upper p a r t was  development,  33 occasionaly d i l a t e d .  The h a i r s produced by them a r e the f i r s t t o  emerge on the s u r f a c e .  No d i s t i n c t i v e  "Annular complex" or  "Haarschiebe" have been d e t e c t e d i n t y l o t r i c h f o l l i c l e s  of  Odocolleus. The developmental are  stages undergone, as observed  (Table I I )  s i m i l a r t o the standard mammalian stages (Lyne and Heideman,  1959)  but owing t o f a s t e r r a t e of embryonic  two ahead of other c e n t r a l p r i m a r i e s .  growth are a stage or  They d i f f e r i n some anatom-  i c a l f e a t u r e s a l r e a d y d i s c u s s e d and i n the l o n g e r p e r i o d of h a i r growth — t h u s  they are the f i r s t t o r i s e and l a s t t o come to r e s t .  A l l i n a l l the present evidence suggests that 'the l a r g e guard f o l l i c l e s  of Odocolleus, though m o r p h o l o g i c a l l y a  little  d i f f e r e n t , are developmentally and f u n c t i o n a l l y r e l a t e d t o t y l o t r i c h s of S t r a i l e  (i960).  The Intermediate guard h a i r f o l l i c l e The overwhelming m a j o r i t y of f o l l i c l e s g i v i n g r i s e t o the overcoat of Odooolleus belong t o t h i s c a t e g o r y .  They c o n s i s t of  c e n t r a l p r i m a r i e s ( i . e . a l l other than these g i v i n g r i s e t o l a r g e guard h a i r s ) and a l l the l a t e r a l p r i m a r i e s . are  The l a t e r a l p r i m a r i e s  s m a l l e r i n s i z e than the c e n t r a l p r i m a r i e s and the d i f f e r e n c e  i s a l s o r e f l e c t e d i n the h a i r s Due  produced.  t o r e l a t i v e abundance of t h i s type of f o l l i c l e  —their  development has been s t u d i e d i n g r e a t e r d e t a i l , p a r t i c u l a r l y so i n case of c e n t r a l p r i m a r i e s because  of t h e i r l a r g e  size.  TABLE I I Follicle No.  Forehead Rump Length  T80A  4-6.2  T2?  8 9 . 5  C e n t r a l primary Large guard h a i r s  types and t h e i r development  B C e n t r a l primary Intermediate Guard h a i r s  stages  L a t e r a l primary Intermediate Guard h a i r s  T36  112.0  1A*  1A  1A  T4-1A  181.5  2B  2B  2A  T4-6B  202.0  2B  2B  2A  T54  211.5  3A-3B  2B-3A  2B  T4-0A  2 3 5 . 0  3B-4-  3B-3A  2B-3A  T56A  2 3 6 . 0  4 - 5  4-  »1  2 6 9 . 5  6,7,8  5 - 6  T82  287.0  8  8  T63A  3 2 1 . 0  8  516 O B  3 3 5 . 0  T66  D F i r s t formed Secondary  3B  k  1A-2A  7-8  3a-3B  8  8  8  8  8  8  3 6 6 . 0  8  8  8  T69  4-22.0  8  8  8  T70A  4-4-8.0  9  9  9  9  10B-10C  10C  Fawn  5 weeks 10B-10C 10B-10C * D e t a i l s of stages g i v e n on pp 1 5 - 1 6  E L a t e r formed Secondary  la-2A  Still  forming  35 C e n t r a l Intermediate guard h a i r f o l l i c l e s  ( c e n t r a l primary type)  A 112 mm f o e t u s shows these f o l l i c l e s  i n stage l a . The  d e v e l o p i n g f o l l i c l e anlagen a r e l o c a t e d a t i n t e r v a l s of a p p r o x i mately 250/^ t o 294  .  At t h i s stage the diameter o f t h i s  p a p i l l a i s g r e a t e r than i t s depth. the  These anlagen a r e formed "by  p r o l i f e r a t i v e a c t i v i t y o f the b a s a l l a y e r of epidermis and  make i n d e n t a t i o n i n the dermo-epidermal 70/*- wide and 16/*- i n depth.  Junction.  They a r e about  The dermal elements a l s o a r e more  t h i c k l y l o c a t e d below these anlagen —  thus the a s s o c i a t i o n o f  dermal elements w i t h the h a i r f o l l i c l e s t a r t s v e r y e a r l y . By 181 mm stage the f o l l i c l e s have reached the p r e p a p i l l a stage i . e . I s stage 2b.  The growing f o l l i c l e s appear as rods of  u n d i f f e r e n t i a t e d c e l l s , e n c l o s e d i n an o r g a n i z e d c e l l l a y e r of one c e l l thickness.  The d i s t a l end of these growing f o l l i c l e s i s  marked by the presence of a mass of c e l l s o f dermal o r i g i n . l a t t e r c o n s t i t u t e the dermal p a p i l l a o f the growing  These  follicles.  In a d d i t i o n t o t h i s a sheath of dermal o r i g i n c o v e r s the growing h a i r f o l l i c l e and the dermal p a p i l l a .  T h i s i s a k i n t o the connec-  t i v e t i s s u e sheath o f the mature f o l l i c l e .  The dermal p a p i l l a a t  t h i s stage i s 16/*- deep w h i l e the f o l l i c l e depth v a r i e s from 1 5 0 / ^ to 1 1 7 A At  236 mm stage the f o l l i c l e s have reached stages v a r y i n g  from 3b t o 4-. dermal p a p i l l a . of  The base of the f o l l i c l e has begun t o envelop the The e n t a l s w e l l i n g i s present t h e r e .  f o l l i c l e p e n e t r a t i o n i s 226/*- t o At  2 3 5 •  269 mm stage the f o l l i c l e s a r e i n stages 5 t o 6 and  have reached depths from 252 At  The depth  to 2 6 8 ^ .  287 mm stage a l l f o l l i c l e s  of t h i s type have reached  Central intermediate  guard h a i r  follicles  FIGURE 12.1 Longitudinal section.  H.& E.  FIGURE 12.2 Transverse s e c t i o n . N o t i c e sweat gland and sebaceous r e l a t i o n s h i p and a r r e c t o r p l l i i muscle. H. & E. White t i p p e d h a i r f o l l i c l e s and l a t e r a l mediate guard h a i r f o l l i c l e s  inter  FIGURE 13.1 L o n g i t u d i n a l s e c t i o n white t i p p e d h a i r . N o t i c e g r e a t e r development o f c o r t e x . H. & E.  FIGURE 13.2 Transverse s e c t i o n . N o t i c e g r e a t e r development of e x t e r n a l r o o t sheath i n l a r g e guard h a i r . In white t i p p e d h a i r s c o r t e x i s b e t t e r developed. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s see Appendix IV, Page 2Ik.  used  please  37  Ap  FIG 13. I  FIG  13. 2  38 stage 8 i . e . h a i r emerged.  These f o l l i c l e s a r e s t i l l  h a i r a c t i v e l y when the fawn i s born, i . e . 4 4 8 mm  stage  and stage n i n e i s not reached u n t i l few weeks a f t e r L a t e r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s These resemble  growing (about)  birth.  ( l a t e r a l primaries)  the c e n t r a l i n t e r m e d i a t e guard h a i r  c l e s i n a l l major r e s p e c t s — but are s m a l l e r i n s i z e .  folli-  They are  i n i t i a t e d a l i t t l e l a t e r than the c e n t r a l p r i m a r i e s , and consequently l a g behind 2 to 3 stages i n development. i n 2 8 7 nun stage the c e n t r a l i n t e r m e d i a t e guard h a i r  For example  follicles  have reached stage 8 i . e . h a i r emerged, the l a t e r a l i n t e r m e d i a t e guard h a i r f o l l i c l e s appear t o be In stages v a r y i n g from 5 t o 4, as n o t i c e d from Table I I . At t h i s stage one would r e c o l l e c t t h a t the fawn b i r t h coat has white spots — caused by white t i p p e d h a i r s o c c u r r i n g i n t h a t region.  These a r e i n t e r m e d i a t e guard h a i r s a r i s i n g i n some of  the c e n t r a l p r i m a r i e s and l a t e r a l p r i m a r i e s . follicles  A n a t o m i c a l l y the  i n which they a r i s e are s i m i l a r to the other i n t e r -  mediate guard h a i r f o l l i c l e s  — except i n the f o l l o w i n g :  a) The dermal p a p i l l a has a p o i n t e d apex and i s not of the normal s p a t u l a t e type. b) The c o r t e x i s two t o three times t h i c k e r than i n the normal i n t e r m e d i a t e guard h a i r . c) The medulla i s made up of c e l l s which are f i l l e d w i t h g r a n u l a r ( t r i c h o h y a l i n ) d e p o s i t s . No i n t r a c e l l u l a r c a v i t i e s are formed. These c e l l s are r e m i n l n s c e n t of normal medullary c e l l s a t a stage Just p r i o r t o f o r m a t i o n of i n t r a c e l l u l a r c a v i t i e s . I t would thus appear t h a t i n white t i p p e d h a i r s the f o r m a t i o n of i n t r a c e l l u l a r medullary c a v i t i e s i s a r r e s t e d . d) Melanocytes are p r e s e n t i n the f o l l i c l e s — a n d they are c o n f i n e d to the c o r t i c a l r e g i o n . The p o r t i o n of c o r t e x above the b u l b appears dark — but subsequently the pigmentation d i l u t e s and the c o r t e x appears, whitish-yellow.  39 In many mammals h a i r i s not u n i f o r m l y c o l o u r e d but i t has a t e r m i n a l or subterminal band c o n t a i n i n g pheomelanin, and the base has melanin  (agouti p a t t e r n ) .  The white t i p p e d h a i r s of  Odocolleus, as w e l l the w i n t e r c o a t guard h a i r s a r e o f t h i s In  type.  b i c o l o u r e d h a i r s each f o l l i c l e s e c r e t e s a l l the pigments,  o c c u r r i n g i n a h a i r , the type of pigment s e c r e t e d v a r y i n g w i t h stage o f h a i r growth c y c l e .  Systemic  c o n d i t i o n s may a l t e r the  i n t e n s i t y of the pigment present i n any l o c a l i t y .  ."Pltzpatrlck  et a l ( 1 9 5 8 ) . In b i o c h e m i c a l a c t i v i t y i n r e l a t i o n t o pigment i s thus d i f f e r e n t i n white t i p p e d h a i r and the v a r i a t i o n i n t h i s  activity  i n r e l a t i o n t o the f o l l i c l e producing pigmented h a i r s i s an i n t e r e s t i n g b i o c h e m i c a l problem i n i t s e l f . Woolly under h a i r f o l l i c l e s These a r e secondary  (secondary  follicles)  f o l l i c l e s and a r e of two types, the  f i r s t formed — p o s s e s s i n g sweat gland, sebaceous gland, a r r e c t o r p i l i i muscle and producing a s m a l l but medullated h a i r , and the l a t e r formed p o s s e s s i n g o n l y sebaceous gland and producing a non medullated woolly-type h a i r . fully second  The f o l l i c l e s  of f i r s t type a r e  formed and have emergent h a i r s p r e n a t a l l y .  Those of the  type continue t o from p r e n a t a l l y as w e l l as p o s t n a t a l l y —  and become f u l l y  f u n c t i o n a l and e f f e c t i v e i n the fawn w i n t e r c o a t .  As the m a t e r i a l i n v e s t i g a t e d i s p r e n a t a l my emphasis i s on development o f f i r s t formed secondary  follicles.  In a 2 6 9 mm f o e t u s these a r i s e s i n g l y .  They a r e the f i r s t  formed w o o l l y f o l l i c l e s and a r e i n developmental In  stage l a t o 2 a .  2 8 7 mm stage the f i r s t formed w o o l l y f o l l i c l e s have  40 developed  a f u l l complement of a c c e s s o r i e s .  secondary  follicles  groups and  and  l a t e r formed  they a r i s e i n p a i r s or  i n d i v i d u a l l y are of v a r y i n g s i z e s and  stages 2 to 3 a . I n 2 3 1 mm  are forming by now  The  in  developmental  There i s no t r a c e of the sebaceous gland as y e t .  stage the c e l l s c o n s t i t u t i n g the core of l a t e r formed  s e c o n d a r i e s show "upward streaming" appearance.  Melanocytes a r e  By 3 3 5 nun stage the h a i r s have d e f i n i t e l y emerged  also noticed.  i n a l l of the f i r s t formed s e c o n d a r i e s . are s t i l l d e v e l o p i n g and new  L a t e r formed  ones forming.  secondaries  The f i r s t  s e c o n d a r i e s o f t e n possess a bent b u l b end — t h e  formed  external root  sheath being s l i g h t l y t h i c k e r i n the angle of the bend. At 3 3 6 mm  stage — some of the f i r s t  formed secondaries have  s t a r t e d r e a c h i n g r e s t i n g stage, but the l a t e r formed s t i l l appear to be d e v e l o p i n g through  stages 2 b to 3 a .  t r e n d i s continued i n subsequent samples. all  secondaries This  In a f i v e week fawn  f i r s t formed secondaries are i n r e s t i n g stage but l a t e r formed  s e c o n d a r i e s a r e s t i l l forming and d e v e l o p i n g . l i s h e d the age a t which a l l f o l l i c l e s  I have not  estab-  are complete.  F o l l i c l e anatomy Montagna  ( 1 9 5 6 )  and Montagna and E l l i s  ( 1 9 5 8 )  have summar-  i z e d the c u r r e n t concepts about s t r u c t u r e of the h a i r and  i t s function.  ( 1 9 6 5 ) ,  Cohen  S t u d i e s of S t r a i l e  ( 1 9 6 5 ) .  c e l l u l a r and  on f o l l i c l e  My m a t e r i a l d i d not permit  intracellular detail.  Auber's  ( 1 9 5 0 )  of study  contribution  anatomy i s of p a r t i c u l a r importance here as i t d e a l s  w i t h an ungulate h a i r f o l l i c l e follicle  P r i e s t l y and B u d a l l  have a l s o f u r t h e r e d our understanding  some of i t s s t r u c t u r a l a s p e c t s . of  ( 1 9 6 5 ) ,  follicle  (sheep).  A n a t o m i c a l l y the h a i r  can be c o n s i d e r e d i n the f o l l o w i n g p a r t s .  Secondary f o l l i c l e s FIGURE 14.1 Developing secondary f o l l i c l e s . Longitudinal section. Notice the developing f o l l i c l e and the dermal papilla-; H. & E. FIGURE 14-. 2 Paired secondary f o l l i c l e s developing. Longitudinal s e c t i o n . One member i s larger than the other. H. & E. FIGURE 14.3 Branching secondary f o l l i c l e s . Longitudinal section. H. & E. FIGURE 14.4 F i r s t formed and l a t e r formed secondaries. Longitudinal s e c t i o n . Notice the arrector p i l i i muscle i n f i r s t formed secondary f o l l i c l e . H. & E. For explanation of abbreviations used please see Appendix IV; Page 214.  42  FIGURE 14.5 P a i r e d secondary f o l l i c l e s i n a d u l t m a t e r i a l . L o n g i t u d i n a l s e c t i o n . Notice the compact epidermis the p e e l i n g stratum corneum and the non medullated hairs i n f o l l i c l e s . H. & E.  FIGURE 14.6 Secondary f o l l i c l e s , a d u l t m a t e r i a l , l o n g i t u d i n a l s e c t i o n , of lower p a r t . Notice the w e l l developed e x t e r n a l r o o t sheath and i t s membranes. The h a i r produced i s non medullated. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s see Appendix IV, Page 214.  used  please  44  F i g . 15.  D e t a i l s of f o l l i c l e  anatomy.  46  E N T A L SIDE  ECTAL SIDE  FIBRE  STRATUM CORNEUM.. EPIDERMIS  DISTAL (UPPER) REGIONS  DUCT O F SEBACEOUS SWEATGLAND  FIG. 15.1 LONGITUDINALSECTION OF PRIMARY FOLLICLE  PROXIMAL (LOWER) REGIONS OUTER ROOT-SHEATH ECTAL SIDE OF FOLLICLE  E N T A L SIDE OF F O L L I C L E  OUTER ROOT-SHEATH H E N L E S LAYERHUXLEY'S  I  LAYER-i  ROOT-SHEATH-, I !  CUTICLE OF  — FIBREj I  CORTEX J! ! j MEDULLA ! !l ! ! UNDIFFERENTIATED REGION OF BULB  FIG. 15.2 DETAILS OF BULB, LONGITUDINAL SECTION  FIG. 15.3 DETAILS OF MEDULLA"  ITOSES REGION O F HOMAXONOUS C E L L S  NUCLEAR CAVITY  AFTER  AUBER  (1950)  47 The c o n n e c t i v e t i s s u e sheath T h i s i s common t o a l l types of f o l l i c l e s . elements a r e a s s o c i a t e d w i t h the f o l l i c l e s subsequent  developmental  The dermal  s i n c e stage l a . I n  stages there i s a d e f i n i t e c o n n e c t i v e  t i s s u e l a y e r e n c l o s i n g the f o l l i c l e and dermal p a p i l l a .  In  e a r l i e r stages i t i s continuous w i t h the dermal p a p i l l a — i n l a t e r stages i t i s d i s t i n c t from i t . c e l l s a r e compactly  I n mature f o l l i c l e s  l't'.s  arranged.  The g l a s s y membrane T h i s i s a c h a r a c t e r i s t i c f e a t u r e o f a l l f o l l i c l e s but i s v i s i b l e o n l y i n those t h a t a r e mature but a b t i v e l y growing, only i n the lower segment.  then  I t i s a h y a l i n e g l a s s y membrane  l o c a t e d between the e x t e r n a l r o o t sheath and c o n n e c t i v e t i s s u e sheath.  T h i s membrane i s more prominent,  ness i n the secondary f o l l i c l e s ,  almost double the t h i c k -  than i n the primary.  a s i m i l a r membranous s t r u c t u r e has a l s o been detected e x t e r n a l r o o t sheath and the inner r o o t sheath.  Curiously between the  Such a membrane  has not been r e f e r r e d t o i n any other f o l l i c l e s and may be a characteristic cervid feature.  I t i s not always c l e a r l y  visible  none the l e s s i s a f a c e t worthy of f u r t h e r i n v e s t i g a t i o n . External root  sheath  In the e a r l y f o e t a l stages t h i s I s d i s t i n g u i s h e d by i t s l a r g e r c e l l s and n u c l e i and by the f a c t t h a t i t forms the bounda r y of the f o l l i c l e .  I n the 287 mm stage onward the e x t e r n a l  r o o t sheath a t t a i n s i t s c h a r a c t e r i s t i c form and the c e l l s have a c l e a r cytoplasm and prominent  nuclei.  48  Anatomically three  the e x t e r n a l r o o t sheath can be d i v i d e d i n t o  regions. a) As a c o v e r i n g t h i c k n e s s and cells.  of the f o l l i c l e b u l b i t i s one c e l l e d i n i t i s made up of compact w e l l n u c l e a t e d  b) In the p a r t of f o l l i c l e above the bulb i t has a s t r a t i f i e d s t r u c t u r e , here i t becomes two to three layered. The c e l l s a d j o i n i n g the i n n e r r o o t sheath are i r r e g u l a r i n o u t l i n e w i t h o v a l n u c l e i . Those towards the p e r i p h e r y are o r i e n t e d i n a d i r e c t i o n p e r p e n d i c u l a r to the a x i s of the f o l l i c l e and bear elongated n u c l e i . c) Towards the apex of the f o l l i c l e the e x t e r n a l r o o t sheath becomes reduced i n t h i c k n e s s and merges w i t h epidermis. T h i s i s n o t i c e d i n a l l the f o l l i c l e  types.  r o o t sheath of the l a r g e guard h a i r f o l l i c l e  times t h i c k e r on one  external  i s t h i c k e r and  l a r g e r c e l l s when compared to the other f o l l i c l e s . of l a t e r formed secondaries  The  the  has  In the case  the e x t e r n a l r o o t sheath appears a t  s i d e than on the other,  but t h i s i s not  uniform at a l l . The  inner r o o t  sheath  S t a r t i n g from the p e r i p h e r y  the i n n e r r o o t sheath c o n s i s t s  of the f o l l o w i n g l a y e r s : a) H e n l e s l a y e r 1  b) Huxley's l a y e r c) Inner r o o t sheath c u t i c l e In Odocolleus the inner r o o t sheath does not  show any  r a d i c a l departure from the g e n e r a l mammalian f e a t u r e s . r o o t sheath components are not c l e a r l y observable i n the n a t a l l y developing  follicles.  The  inner  pre-  They are best s t u d i e d i n the upper  h a l f of the bulb of the a d u l t f o l l i c l e when a c t i v e l y producing h a i r , and my  observations  on them are as  follows:  Deer primary f o l l i c l e  bulb  FIGURE 16.1 Close up of f o l l i c l e b u l b . L o n g i t u d i n a l s e c t i o n . N o t i c e the dermal p a p i l l a and i t s s t a l k , so a l s o other f o l l i c l e components. H. & E . FIGURE 16.2 C e l l l a y e r s i n the i n n e r r o o t sheath. L o n g i t u d i n a l s e c t i o n . N o t i c e c e l l s o f Henle's l a y e r , Huxley's l a y e r , i n n e r r o o t sheath c u t i c l e and h a i r c u t i c l e . H. & E. Medulla  formation  FIGURE 17.1 Medulla i n primary h a i r f o l l i c l e . intracellular cavities. H. & E .  N o t i c e the  FIGURE 17.2 Medulla i n white t i p p e d h a i r of fawn b i r t h c o a t . N o t i c e the absence of i n t r a - c e l l u l a r cavities. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s used please see Appendix IV. Page 214.  50  Fib  F  SWD  51 Henle s 1  layer  Most prominent l a r g e and rounded.  of i n n e r r o o t sheath l a y e r s .  C e l l s are  I t i s bounded on the outer s i d e by a g l a s s y  membrane, v i s i b l e a t p l a c e s and then beyond t h a t by the e x t e r n a l r o o t sheath.  I t i s one c e l l e d i n s t r u c t u r e and i s more d a r k l y  s t a i n i n g w i t h e o s i n - haematoxylin than other i n n e r r o o t l a y e r s . The l a y e r a l s o has f i b r o u s m a t e r i a l whose percentage i n c r e a s e s as one proceeds towards the f o l l i c l e  orifice.  Huxley's l a y e r T h i s a l s o i s one c e l l e d i n t h i c k n e s s , but the c e l l s are oval, a l i t t l e it  s m a l l e r than Henle's l a y e r c e l l s , and compared to  are l i g h t l y s t a i n i n g .  Inner r o o t sheath c u t i c l e These c e l l s are rounded i n n e r r o o t sheath c e l l s .  i n o u t l i n e and the s m a l l e s t of  As they r i s e upwards they elongate i n  the d i r e c t i o n of the f o l l i c l e a x i s , and form downward p o i n t i n g s c a l e s which i n t e r l o c k w i t h those of the h a i r c u t i c l e .  Thus the  h a i r and the i n n e r r o o t sheath move upwards t o g e t h e r i n the cle  till  they r e a c h the v i c i n i t y of the sebaceous  the i n n e r r o o t sheath breaks up.  gland, where  The Henle's and Huxley's l a y e r  f u s e t o g e t h e r i n the upper reaches of the f o l l i c l e , a l s o break up i n the v i c i n i t y of the sebaceous Straile  folli-  till  they  gland.  (19&5) suggests t h a t the r o o t sheath and the dermal  p a p i l l a together a f f e c t the shape, s i z e and movement of h a i r and t h e r e f o r e appear t o be of g r e a t  consequence.  52 The  f i b r e anatomy The  f i b r e can be d i v i d e d i n t o i t s three components,  c u t i c l e , c o r t e x and  medulla.  The h a i r c u t i c l e In the upper r e g i o n s of the bulb, the h a i r c u t i c l e  cells,  which are rounded and l a r g e r than the a d j o i n i n g c e l l s of i n n e r r o o t sheath,  c u t i c l e , are easy to d i s t i n g u i s h . As they  upwards they elongate  i n the a x i s of the f o l l i c l e and form the  c u t i c u l a r s c a l e s of the h a i r . i n t e r l o c k w i t h those The  rise  These are p o i n t i n g upwards and  of the i n n e r r o o t  sheath.  cortex Auber (1950) c a t e g o r i z e s the d i f f e r e n t i a t i o n of c o r t e x  w i t h i n a f i b r e i n t o four a) The  stages.  "preelongation region"  b) The r e g i o n of " c e l l u l a r  elongation"  c) The  c o r t i c a l "prekeratlnization region"  d) The  fully  "keratinized region"  In Odocolleus observed w e l l .  the f o r m a t i o n of the c o r t e x has not been  In h a i r f i b r e s w i t h prominent medulla, the  i s reduced to a t h i n s t r i p between the h a i r c u t i c l e and medulla.  Most of the guard h a i r s are of t h i s type.  s m a l l e r f i b r e s , e.g. absent and  l a t e r formed secondaries,  cortex  the  But i n  the medulla i s  the c o r t e x w i t h i t s sheath of c u t i c l e c o n s t i t u t e s the  fibre. In the other h a l f of the bulb the c o r t i c a l c e l l s are a c t e r i z e d by t h e i r rounded appearance and  l a r g e number of  char-  53 melanocytes.  I n the h i g h e r r e g i o n s of the "bulb the c o r t i c a l  c e l l s g e t elongated i n the a x i s of the f o l l i c l e and when f u l l y k e r a t i n i z e d from a compact homogeneous mass.  No evidence o f  c o r t i c a l f u s i has been d e t e c t e d i n O d o c o l l e u s .  I n the guard  hairs  the c o r t e x of white t i p p e d h a i r s i s b e t t e r developed and i s two to t h r e e times t h i c k e r than that of other guard The  hairs.  medulla I n Odocolleus many of the guard h a i r s a r e h e a v i l y  medullated.  The medullary c e l l s a r e n o t i c e d r i s i n g on each s i d e of the dermal p a p i l l a i n the upper h a l f of the b u l b . they a r e bounded by c o r t i c a l c e l l s .  E x t e r n a l l y on e i t h e r  side  They a r e formed on the lower  p a r t of the b u l b and have l a r g e r n u c l e i than the c o r t i c a l  cells.  I n i t i a l l y t h e i r c e l l margins a r e not d i s t i n c t but when observable are t r i a n g u l a r or rhomboidal  i n form.  The n u c l e i a r e l a r g e and  melanin g r a n u l e s have been n o t i c e d i n the c e l l s .  As the c e l l s  r i s e t o the upper l i m i t s of the dermal p a p i l l a they a r e f u l l of g r a n u l a r and f i b r o u s m a t e r i a l .  As they extend f u r t h e r , vacuoles  form i n the c e l l s and Increase i n s i z e , subsequently  occupying  the whole c e l l and r e l e g a t i n g the n u c l e i t o the c e l l w a l l n e a r e s t t o the dermal p a p i l l a . q u i t e prominent  The medullary c e l l margins a r e s t r o n g and  and together w i t h the c e n t r a l c a v i t i e s present  the c h a r a c t e r i s t i c medullar f e a t u r e s . Auber ( 1 9 5 0 ) has e l e g a n t l y d i s c u s s e d the f o r m a t i o n of medulla and though Odocolleus f o l l o w s the same g e n e r a l p a t t e r n many of the d e t a i l s as d i s c u s s e d by Auber have not been observed. The f o l l i c l e b u l b and dermal  papilla  The base of the f o l l i c l e which e n c l o s e s the dermal  papilla  54 is  c a l l e d the f o l l i c l e The  bulb.  f o l l i c l e base f i r s t becomes bulbous  i n 181 mm f o e t u s .  The dermal elements l a t e r t o c o n s t i t u t e the dermal p a p i l l a a r e l o c a t e d a d j o i n i n g the f o l l i c l e base.  In a 235 nmi f o e t u s the  f o l l i c l e base gets notched and the dermal p a p i l l a elements present a rounded more compact form.  At 269 mm stage as much as three  fourth's of the dermal p a p i l l a i s enclosed by the f o l l i c l e In cle  base.  a 448 mm f o e t u s the r e l a t i o n s h i p between dermal p a p i l l a  folli-  bulb, and the c o v e r i n g c o n n e c t i v e t i s s u e sheath becomes  apparent.  The dermal p a p i l l a i s more or l e s s f u l l y enclosed by  the f o l l i c l e base and maintains c o n t a c t w i t h the c o n n e c t i v e by means o f a d i s t i n c t s t a l k .  tissue  T h i s i s c h a r a c t e r i s t i c o f the a d u l t  material too. The w a l l of the b u l b i s epidermal i n o r i g i n and an e x t e n s i o n of  the e x t e r n a l r o o t sheath.  to  the c e l l s which c o n s t i t u t e the v a r i o u s f o l l i c l e s and f i b r e  layers.  I t i s responsible f o r giving  rise  These c e l l s as they a r i s e i n the lower h a l f o f the b u l b  are u n d i f f e r e n t i a t e d but as they r i s e t o upper r e g i o n s of the b u l b they g e t organized i n t o the rudiments and f i b r e  of d i f f e r e n t  follicular  layers.  The dermal p a p i l l a , as the name suggests, i s dermal i n o r i g i n and i s b e l i e v e d t o supply n u t r i e n t s t o the d e v e l o p i n g  folli*  cle.  I t c o n s i s t s of an agglomeration  of w e l l n u c l e a t e d c e l l s .  It's  exact r o l e i n the b i o l o g y o f the f o l l i c l e s i s complicated  and not w e l l understood b u t has been d i s c u s s e d by Cohen In  (1965).  Odocolleus i t has been n o t i c e d t h a t h e a v i l y medullated  h a i r f o l l i c l e s have rounded bulbs and s p a t u l a t e dermal p a p i l l a e , whereas i n non medullated h a i r f o l l i c l e s i t Is o v a l and the dermal  55 p a p i l l a has a narrow appearance and p o i n t e d apex. tipped hair f o l l i c l e s ,  I n the white  c h a r a c t e r i z e d by g r e a t e r c o r t e x a s m a l l e r  non v a c u o l a t e d medulla, the dermal p a p i l l a has a p o i n t e d apex. Thus p a p i l l a shape has d i r e c t r e l a t i o n s h i p w i t h the type of h a i r produced.  What e x a c t l y t h i s r e l a t i o n s h i p i s and how  i t operates  i s beyond the scope of the present work. Melanocytes The growing h a i r f o l l i c l e s by the presence In  of  of Odocoileus are c h a r a t e r i z e d  melanocytes.  guard h a i r f o l l i c l e s  they f i r s t appear i n 202 mm  foetus.  The v i s i b l e melanocytes are dark c o l o u r e d , few, and s c a t t e r e d w i t h i n the f o l l i c l e .  Some may  and an i s o l a t e d few may Subsequently  be l o c a t e d i n i t s e x t e r n a l margin  occur even i n b a s a l l a y e r of the e p i d e r m i s .  they c o n c e n t r a t e i n the b u l b .  The melanocytes here  are d e n d r i t i c . Of course the amount of melanocytes depends on the c o l o u r a t i o n and type of f i b r e s being produced.  The melanin d e p o s i t e d  by melanocytes i s c o n f i n e d to the h a i r f i b r e o n l y and there too to  the c o r t e x , and the b a s a l p a r t s of the medulla.  Variations i n  c o l o u r of summer and w i n t e r h a i r s i n a d u l t can be e x p l a i n e d on the b a s i s of the b i o c h e m i c a l a c t i v i t y of  melanocytes.  Sweat gland All follicles,  except those of the w o o l l y u n d e r h a l r ,  a p o c r i n e sweat g l a n d s .  Initially  they develop as bag l i k e  growths from the neck of the f o l l i c l e .  The  possess out-  sweat g l a n d a t t h i s  stage i s a s o l i d outgrowth d e v o i d of any lumen and the c o n s i t u t u i n g i t are s i m i l a r to those of the f o l l i c l e .  cells  Sweat gland FIGURE 18.1 Sweat gland forming a t 202 mm L o n g i t u d i n a l s e c t i o n . H. & E .  stage.  FIGURE 18.2 Sweat gland a t 236 mm s t a g e . L o n g i t u d i n a l s e c t i o n . N o t i c e the p o s i t i o n of sweat gland and a r r e c t o r p i l l i muscle. The h a i r i s d e v e l o p i n g . H. & E i FIGURE 18;3 Sweat gland s e c t i o n . Notice sebaceous gland, has begun. H. &  a t 269 mm stage; L o n g i t u d i n a l i t s desposition i n relation to and the g e n t l e waviness which E. FIGURE 18.4  Sweat gland i n a d u l t m a t e r i a l . L o n g i t u d i n a l s e c t i o n . Note the c o i l s have been s e c t i o n e d and possess a one c e l l t h i c k l i n i n g . The i n n e r r o o t sheath and h a i r c u t i c l e a r e a l s o c l e a r . H. & E . F o r e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV. Page 214.  FIG 18.4  58 By the 211 mm  stage the sweat gland has reached up t o the  top of f o l l i c l e bulb, and d i f f e r e n t i a t i o n begins t o take p l a c e w i t h i n the g l a n d .  The d i s t a l p a r t develops a lumen, but  the  proximal p a r t of the gland, where the sweat duct forms i s a t t h i s stage s t i l l a s o l i d mass of c e l l s .  The complete gland does not  d i f f e r r a d i c a l l y from the t y p i c a l mammalian p a t t e r n i n form or i n The t h i c k n e s s of lumen w a l l i s about 3 3 / ^  constituent c e l l s . the lumen diameter  ( i n n e r ) i s about 184/*- .  i s s i n g l e c e l l e d and duct i s about 4 2 / * - .  The w a l l of the duct  i t s t h i c k n e s s as w e l l as the diameter The  and  of the  sweat duct passes over the s u r f a c e of  the sebaceous gland i n between i t s two l o b e s and opens by means of a f u n n e l shaped opening  i n t o the h a i r f o l l i c l e near the  skin  surface. Sebaceous gland A l l f o l l i c l e s except the s m a l l e s t of the secondaries possess sebaceous g l a n d s .  The p r i m a r i e s and f i r s t  formed  secondary  f o l l i c l e s possess b i l o b e d sebaceous glands, t h i s i s not so i n smaller secondaries. The  sebaceous glands o r i g i n a t e a f t e r the sweat glands,  their f i r s t developed  t r a c e s are observed  first  i n 181 mm  i n larger f o l l i c l e s .  The  foetus.  They are  sebaceous gland r u d i -  ments c o n s i s t of few l a r g e rounded c e l l s w i t h c l e a r cytoplasm prominent n u c l e i . grape bunch.  By 269 mm  By 335 mm  and  and  stage they resemble i n appearance a  the b u l k of the gland i s formed of l a r g e  c e l l s w i t h c l e a r cytoplasm a l a r g e c e n t r a l l y p l a c e d n u c l e u s .  Sebaceous gland FIGURE 19.1 Sebaceous g l a n d rudiment, 2 3 5 mm s t a g e . Longitudinal s e c t i o n . Notice i t s p a r t i c i p a t i o n i n h a i r c a n a l f o r m a t i o n . H. & E . FIGURE 19.2 Sebaceous gland a t 2 6 9 mm s t a g e . L o n g i t u d i n a l s e c t i o n . Notice the t y p i c a l gland c e l l w i t h prominent n u c l e i . The d e v e l o p i n g h a i r i s l y i n g next t o i t . H. & E. FIGURE 19.3 Sebaceous gland opening i n a d u l t m a t e r i a l . L o n g i t u d i n a l s e c t i o n . Notice the lobed nature of the gland and i t s s h o r t duct which opens i n t o the hair f o l l i c l e . H. & E. FIGURE 19.4 Sebaceous gland and the f o l l i c u l a r f o l d s . L o n g i t u d i n a l s e c t i o n . The f o l d s a r e caused by d i s i n t e g r a t i o n of i n n e r r o o t sheath near sebaceous g l a n d . H. & E . For e x p l a n a t i o n o f a b b r e v i a t i o n s used p l e a s e see Appendix IV. Page 214.  60  63) Arrector p l l l l  muscle  T h i s i s present follicles. follicle  i n primary and  f i r s t formed secondary  I t i s formed from dermal f i b r o c y t e s and  on an o b l i q u e course, from a r e g i o n  approches the  j u s t below the  epidermis. In a 2 1 1 mm  f o e t u s the f i b r o c y t e s i n the dermis appear to  be a l i g n i n g to form the muscle. the sweat gland  At t h i s stage one  i s forming a lumen.  between the strands  The  of the developing  d i s t a l end  sweat gland  muscle.  passes  As maturation  proceeds the number of f i b r e s i n c r e a s e s w i t h i n the muscle. are elongated, and  of  They  compactly arranged, and have f l a t t e n e d n u c l e i .  Ental swelling The  h a i r f o l l i c l e as w e l l as the h a i r t h a t i t g i v e s r i s e  to  are always i n c l i n e d a t an angle w i t h r e s p e c t to the s k i n s u r f a c e . The  s i d e forming the acute and  r e f e r r e d to as e n t a l and hair f o l l i c l e s  obtuse angles w i t h the s k i n are  ectal respectively.  The  e n t a l s i d e of  have been n o t i c e d i n many s p e c i e s to possess a  s w e l l i n g d u r i n g the course of development — a s w e l l i n g commonly r e f e r r e d to as the e n t a l s w e l l i n g .  T h i s c o n s t i t u t e s the  where the a r r e c t o r l s p i l i i muscle becomes attached In Odocolleus, i n a 2 1 1 mm just noticeable. 2 8 7 mm  stage onwards i t d i m i n i s h e s .  Heideman  ( 1 9 5 9 )  stage, but  In a c t i v e l y growing  c l e s producing them i t i s not n o t i c e a b l e .  Lyne and  follicle.  f o e t u s the e n t a l s w e l l i n g i s  I t i s more prominent by 2 3 5 mm  e n t a l s w e l l i n g i n the secondary  to the  region  I d i d not f i n d  from  folliany  follicles. have reviewed t h e o r i e s  o r i g i n of the e n t a l s w e l l i n g and  regarding  have concluded t h a t i t i s not  62 formed by t r a c t i o n o f a r r e c t o r p i l i i muscle, as i t i s present even when there i s l i t t l e  or no muscle.  T h i s has a l s o been c o r ^ o -  :^orjated by my o b s e r v a t i o n on the Odocolleus  material.  The h a i r c a n a l Lyne ( 1 9 5 7 ) has d i s c u s s e d a t some l e n g t h the process of h a i r canal formation Observations  i n the merino f o e t u s .  on Odocolleus  t h a t i n merino takes p l a c e here. stratum  i n d i c a t e t h a t a process a k i n t o A 211 mm f o e t u s shows w i t h i n  spinosum g r a n u l a r m a t e r i a l d e p o s i t e d o b l i q u e l y w i t h  r e s p e c t t o the s k i n s u r f a c e .  T h i s i s j u s t above the f o l l i c l e and  appears t o r e p r e s e n t the g r a n u l a t i o n stage r e f e r r e d by Lyne. Simultaneously  sebaceous c e l l s present  a r e i n process  of d i s i n t e g r a t i o n . In a 2 6 9 mm f o e t u s the h a i r  canal i s d i s t i n c t skin surface. and  and l e a d s o b l i q u e l y from h a i r f o l l i c l e towards  The h a i r c a n a l f o r m a t i o n  i s completed by stage 7«  those o f the stratum Paired  i n the neck of the f o l l i c l e  s t a r t s by stages 3a» 3t»,  The sebaceous gland c e l l s as w e l l as  spinosum take p a r t i n i t .  follicles Lyne and Heideman ( 1 9 5 9 ) f i r s t d e s c r i b e d a case where two  f o l l i c l e s develop s e p a r a t e l y but i n c l o s e p r o x i m i t y of each other and  open t o the e x t e r i o r by means o f a common opening. Only secondary f o l l i c l e s of Odooolleus sometimes e x h i b i t s  this.  The common h a i r c a n a l has n o t been e s t a b l i s h e d f o r these  follicles  — but i s l i k e l y s i n c e they have common opening and  arise separately.  Usually i n paired f o l l i c l e s ,  than i t s compatriot.  one i s s m a l l e r  63  Branched The of  follicles l a t t e r formed secondaries i n Odocolleus  occur i n groups  three o r f o u r , of which one f o l l i c l e i s l a r g e and the others  sucessively smaller.  The l a r g e f o l l i c l e may possess  a relatively  l a r g e sebaceous g l a n d and other a s s o r t e d f o l l i c l e s appear : V , i n development t o be d e r i v e d from t h i s l a r g e f o l l i c l e and may l a c k sebaceous g l a n d . F o l l i c l e density The d e n s i t y of h a i r f o l l i c l e s v a r i e s w i t h advancing p stages.  The f o l l i c l e number per mm  e i t h e r by f o r m a t i o n of new f o l l i c l e s  foetal  i s a f f e c t e d i n two ways, or by d i s p e r s a l of f o l l i c l e s  by s t r e t c h i n g of s k i n , due t o i t s growth. The of  f i g u r e s g i v e n here should o n l y be taken as i n d i c a t i v e  the t r e n d , s i n c e c o r r e c t i o n s have not been made f o r t i s s u e  shrinkage  during processing.  I n t h i s t i s s u e s i z e comparisons a r e  b e l i e v e d t o be v a l i d as a l l f o e t u s e s were f i x e d and p r e s e r v e d i n the same manner. At the 202 mm stage o n l y primary due  f o l l i c l e s a r e forming but  t o i n c r e a s e i n f o e t a l s i z e r e s u l t i n g i n s t r e t c h i n g of s k i n ,  though the t o t a l number of f o l l i c l e s per mm  2  number of p r i m a r i e s per mm  2  t h i s stage i s 90 per mm  2  i s decreasing.  i s i n c r e a s i n g the F o l l i c l e density at  (58 primary and 3 2 secondary).  mm stage f o l l i c l e d e n s i t y i s maximum i . e . 108/mm . 2  and  6 0 secondary).  decrease  (48 primary  H e r e a f t e r the f o l l i c l e d e n s i t y c o n t i n u e s t o  and a t b i r t h i t i s about 31/nun  20 s e c o n d a r i e s .  By 287  2  i . e . 1 1 p r i m a r i e s and  64 ".Integumentary  layers  These can "be c o n s i d e r e d i n the form of the two major components, the epidermis and the  dermis.  Chase e t a l (1953)» have made o b s e r v a t i o n s on t h i s s u b j e c t i n mice and Lyne (1957) has d e s c r i b e d the development of epidermis i n merino.  These are i n t e r e s t i n g c o n t r i b u t i o n s shedding l i g h t  on  a s p e c t s of s k i n f r e q u e n t l y i g n o r e d . I n r e s p e c t of Odocolleus I have f o l l o w i n g o b s e r v a t i o n s to make: The  epidermis In an 89 mm  w i t h prominent  stage the epidermis c o n s i s t s of s m a l l c e l l s  rounded n u c l e i .  l a y e r of subsequent  T h i s corresponds t o the b a s a l  epidermal s t a g e s .  With i n c r e a s i n g growth of the f o e t u s the epidermis can be d i s t i n g u i s h e d i n t o the f o l l o w i n g l a y e r s : a stratum or b a s a l l a y e r and a stratum spinosum.  germinativum  The l a t t e r a r i s e s by  p r o l i f e r a t i v e a c t i v i t y of the b a s a l l a y e r over which i t l i e s . I n a 212 mm  f o e t u s i t i s of two l a y e r s .  The c e l l s a r e l a r g e r  than those of the b a s a l l a y e r , have c l e a r cytoplasm and nuclei.  The c e l l s a r e i r r e g u l a r to o v a l and l o o s l y  those nearer the s u r f a c e appear  prominent  arranged,  flattened.  Periderm I t c o n s t i t u t e s s u r f a c e of the s k i n and i s formed by spinosum c e l l s f l a t t e n e d and h y a l i n l z e d .  stratum  I t i s a continous l a y e r  of uniform c o n s i s t e n c y w i t h c e l l u l a r components t h a t cannot distinguished.  be  FIGURE 20  A r r e c t o r p i l i i muscle i n a d u l t m a t e r i a l . L o n g i t u d i n a l s e c t i o n . H. & E.  FIGURE 21 Melanin i n growing h a i r f o l l i c l e s . Notice i t s heavy d e p o s i t i o n i n c o r t i c a l and medulla l a y e r of f o l l i c l e and h a i r . H. & E. Dermis FIGURE 22;0. Dermis i n e a r l y developmental stage. L o n g i t u d i n a l s e c t i o n . H. & E.  FIGURE 22.2Dermis i n a d u l t s t a g e . Longitudinal section. N o t i c e the heavy f i b r o u s d e p o s i t i o n near f o l l i c l e base. H. & E. For explanation of abbreviations see Appendix IVY Page 214.  used please  66  67 In keeping w i t h the advancing  stages o f f o e t a l and f o l l i c l e  development, changes a l s o take p l a c e w i t h i n the e p i d e r m i s .  In  e a r l y stages o f f o l l i c l e development epidermis i n c r e a s e s i n t h i c k n e s s ; "but as h a i r development and muturation proceeds the t h i c k n e s s i s reduced. The  At i t s maximum the epidermis i s 50/*- t h i c k .  i n c r e a s e b e i n g most m a n i f e s t i n the stratum spinosum, which  becomes three c e l l s t h i c k .  I n 235 nun f o e t u s w i t h stages o f  f o l l i c l e development from 2b t o 4 , the epidermal c e l l s show tendency  towards compactness.  At the same time the periderm i s  p e e l i n g o f f and b e i n g r e p l a c e d by another l a y e r of uniform c o n s i s tency c o n t a i n i n g many g r a n u l a r d e p o s i t s .  T h i s g r a n u l a r l a y e r may  be c a l l e d the stratum granulosum. In a 269 mm f o e t u s some h a i r s have emerged, and the e p i d e r mis  i s g r e a t l y reduced  i n s i z e b e i n g 25/*" t h i c k .  The stratum  corneum shows laminated s t r u c t u r e and the; stratum spinosum i s two l a y e r e d w i t h f l a t t e n e d c e l l s .  I n a 4 4 8 mm stage i . e . when  fawn i s about t o be born, the stratum spinosum has l o s t as a separate l a y e r .  S c a t t e r e d c e l l s may however be n o t i c e d  between the stratum germinativum  and the prominent stratum corneum.  In a mature a d u l t the epidermis i s The  i t s entity  2$thick.  dermis The p r e s e r v a t i o n of my m a t e r i a l was inadequate  d e t a i l e d study of the v a r i o u s  elements.  t o permit  Epidermis FIGURE  23.1  Developing e p i d e r m i s . L o n g i t u d i n a l s e c t i o n . 46.2 mm s t a g e . N o t i c e the stratum germinatlvum and the l o o s l y arranged dermal elements. H. & E. FIGURE  23.2  Developing epidermis a t 112 mm s t a g e . L o n g i t u d i n a l s e c t i o n ; Note the d i s t i n c t i v e stratum germinativum, f o l l i c l e anlagen i n i t , two l a y e r e d stratum spinosum and the periderm. Hi & E i FIGURE  23.3  Developing e p i d e r m i s . L o n g i t u d i n a l s e c t i o n . N o t i c e the enlarged nature of stratum spinosum. H. & E. FIGURE  23.4  Epidermis i n a d u l t m a t e r i a l . L o n g i t u d i n a l section. Notice the p e e l i n g stratum corneum and compact nature of epidermis and f i b r o u s dermis. H. & E. F o r e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV. Page 214.  69  70 Summary The h a i r f o l l i c l e s primary and secondary  of Odocolleus can be d i v i d e d  into  types.  The p r i m a r i e s are f i r s t t o o r i g i n a t e , and develop c o n s i s t i n g of a l a r g e r c e n t r a l primary f o l l i c l e and two l a t e r a l primary f o l l i c l e s . developmental  stages.  A l l p r i m a r i e s possess sweat gland,  f o l l i c l e s begins by 1 1 2 mm  The  smaller  T h i s grouping i s obvious d u r i n g e a r l y  sebaceous gland and p i l i i muscle.  producing  in trios  The development of the  and by 4 4 8 mm  stage they are a c t i v e l y  hair. s e c o n d a r i e s are s m a l l e r i n s i z e , a r i s e l a t e r and are  d i v i d e d i n t o f i r s t formed and l a t e r formed.  The f i r s t formed  s e c o n d a r i e s a r e l a r g e r and possess a sweat gland, a sebaceous gland and a r r e c t o r p i l i i muscle.  They s t a r t d e v e l o p i n g by 2 6 9  mm  stage and by 4 4 8 are a c t i v e l y producing h a i r , some f o l l i c l e s do even r e a c h r e s t i n g s t a g e s .  The l a t e r formed secondaries are  s m a l l e r than the f i r s t formed, possess only sebaceous glands, the s m a l l e s t among them may p a i r e d or branched.  even l a c k these; they may  When branched  be  and  single,  they are i n c l u s t e r s of 3 t o 4  and a r e of g r a d u a l l y d e c r e a s i n g s i z e s .  The l a t e r formed  secon-  d a r i e s continue t o form even p o s t n a t a l l y and do not become  fully  f u n c t i o n a l u n t i l i n the fawn w i n t e r c o a t . Some of the c e n t r a l p r i m a r i e s grow and develop a t a f a s t e r r a t e , dwarfing f o l l i c l e s a d j a c e n t t o them. n o t i c e a b l e a t 2 8 ? mm  This i s p a r t i c u l a r l y  stage, subsequently the s i z e d i s c r e p a n c y  gets reduced and i s h a r d l y n o t i c e a b l e p o s t n a t a l l y .  The neck of  these f o l l i c l e s has been observed t o assume o c c a s i o n a l l y a  71 bulbous form, but no d e f i n i t i v e sinus has been d e t e c t e d .  These  f o l l i c l e s have most of the c h a r a c t e r i s t i c s and a l s o the f u n c t i o n of the t y l o t r i c h f o l l i c l e s present The The  i n mammals.  types of h a i r produced by the f o l l i c l e s are v a r i e d .  l a r g e guard h a i r f o l l i c l e s produce l a r g e guard h a i r s  ( t y l o t r i c h s ?) which are l o n g e r and  t a c t i l e i n function.  r e s t of the primary f o l l i c l e s produce the i n t e r m e d i a t e h a i r s , c o n s t i t u t i n g the animal's overcoat.  The  guard  Some of the  primaries  i n fawn b i r t h coat produce white t i p p e d h a i r s , r e s p o n s i b l e f o r the white spots i n the b i r t h c o a t .  A l l p r i m a r i e s and  secondaries  produce medullated h a i r s , w h i l e  secondaries  produce non medullated h a i r s .  Anatomically The  f i r s t formed  the l a t e r formed  the f o l l i c l e s have b a s i c mammalian f e a t u r e s .  f o l l o w i n g amongst them are however c h a r a c t e r i s t i c and  note-  worthy. a) A g l a s s y membrane between connective t i s s u e sheath and the e x t e r n a l r o o t sheath i s prominent a t p l a c e s , even on the f o l l i c l e b u l b . b) An a d d i t i o n a l g l a s s y membrane i s a l s o n o t i c e d a t p l a c e s between e x t e r n a l r o o t sheath and the i n t e r n a l r o o t sheath. c) The e x t e r n a l r o o t sheath i s of uniform the f o l l i c l e .  t h i c k n e s s around  d) Henle's l a y e r i s s i n g l e c e l l e d and l a r g e , s t a i n i n g more deeply w i t h Haematoxylin and E o s i n than does Huxley's l a y e r , which i s a l s o s i n g l e c e l l e d but s m a l l e r . The  shape of the dermal p a p i l l a v a r i e s w i t h the h a i r type  being produced. it  In f o l l i c l e s producing  i s spatulated, while  h e a v i l y medullated h a i r s  i n those producing  non medullated h a i r s  i t has a p o i n t e d apex; i t i s a l s o p o i n t e d i n the primary f o l l i c l e s , producing  white t i p p e d h a i r s .  In the e a r l y f o l l i c l e development the observable  melanocytes  72  are few and s c a t t e r e d . the e p i d e r m i s .  Some may occur even i n the b a s a l l a y e r o f  By the time h a i r p r o d u c t i o n commences, they assume  d e n t r i t l c form and a r e h e a v i l y c o n c e n t r a t e d i n the f o l l i c l e In  g e n e r a l the pigmentation  to  the c o r t i c a l r e g i o n .  bulb.  i s c o n f i n e d t o the h a i r c u t i c l e , and  Some d e p o s i t i o n may be n o t i c e d even i n  the b a s a l r e g i o n o f the medulla. The to  e n t a l s w e l l i n g i n Odocolleus f o l l i c l e s  was r e s t r i c t e d  p r i m a r i e s and d i d n o t have any cause and e f f e c t  w i t h the a r r e c t o r p i l i i In follicles  muscle.  the h a i r s produced the medulla  relationship  i n primary and f i r s t formed  i s b e t t e r developed  secondary  than the c o r t e x .  The  h a i r s from l a t e r formed secondaries i n c o n t r a s t a r e non medullated and c o n s i s t of c o r t e x and h a i r c u t i c l e . of  The bulk of the l o n g t i p  a l a r g e guard h a i r i s made of c o r t e x —  begins t o form e a r l i e r than the medulla.  as c o r t i c a l  tissue  The white t i p p e d h a i r s ,  have i n the r e g i o n of the white t i p s g r e a t e r p r o p o r t i o n a l development o f c o r t e x than other medullated  hairs.  The medulla i n Odocoileus i s very w e l l developed and i s c h a r a c t e r i z e d by presence  of i n t r a c e l l u l a r c a v i t i e s .  The white  t i p p e d h a i r s have however a medulla l a c k i n g i n c a v i t i e s ; and the medullary c e l l s a r e i n s t e a d f i l l e d w i t h porous and g r a n u l a r m a t e r i a l , r e m i n i s c e n t of stages p r i o r t o c a v i t y f o r m a t i o n i n normal medulla. The sinuous.  sweat gland i s prominent and i t s s e c r e t o r y p a r t i s The sebaceous glands a r e w e l l formed, g e n e r a l l y b i l o b e d  i n primary and f i r s t distinct aclnli.  formed s e c o n d a r i e s , and do not possess  They have a s h o r t e x c r e t i o n duct and d u r i n g  development p a r t i c i p a t e i n h a i r c a n a l f o r m a t i o n .  73  The epidermis undergoes profound change of s i z e d u r i n g f o l l i c l e development.  The l a y e r most a f f e c t e d i s stratum  which i s t h r e e l a y e r e d a t one stage and i n a d u l t animal d i s a p p e a r s as an e n t i t y .  spinosum,  almost  Evidence of periderm being sloughed o f f  d u r i n g embryonic development i s a l s o p r e s e n t .  The stratum  corneum  of a d u l t m a t e r i a l has a l s o peeled appearance. The dermis d u r i n g development gets more and more compact and w e l l o r g a n i z e d .  The c o l l a g e n f i b r e s i n the r e t i c u l a r  r e a c h massive p r o p o r t i o n s i n the a d u l t .  layer  74 Chapter IV PELAGE MORPHOLOGY AND MOULT PATTERNS  INTRODUCTION The  present chapter d e a l s with b l a c k t a l l pelage,  the h a i r s produced by the f o l l i c l e s ,  that i s  t h e i r morphology and moult  patterns. I t appears c e r t a i n t h a t m o r p h o l o g i c a l  features of hair  c o n s t i t u t i n g the pelage c o n t r i b u t e t o i t s f u n c t i o n a l e f f i c i e n c y . The  t i m i n g of the moult a l s o normally bears an important  s h i p t o p r e v a i l i n g environmental wards the animal's During possess  relation-  c o n d i t i o n s and i s o r i e n t e d t o -  well-being.  i t s l i f e c y c l e a b l a c k t a i l e d deer can be s a i d t o  f o u r d i f f e r e n t pelage  types.  These a r e :  a) Pawn b i r t h coat b) Pawn winter coat c) A d u l t summer coat d) A d u l t w i n t e r  coat  I have s t u d i e d the d i s t i n c t i v e f e a t u r e s of these  different  pelages and the p a t t e r n and t i m i n g of the moult. MATERIAL AND METHODS The  study i n v o l v e d use o f l i v e deer as w e l l as tanned h i d e s .  The h i d e s were used f o r a g e n e r a l d e s c r i p t i o n of the summer and w i n t e r phases of the a d u l t coat as w e l l as the fawn b i r t h  coat.  The winter coat of the fawn, as w e l l as the moult p a t t e r n i n animals animals.  has been d i s c u s s e d on the b a s i s of o b s e r v a t i o n s on l i v i n g H a i r samples f o r measurement and d e s c r i p t i o n were  c o l l e c t e d from s p e c i f i e d r e g i o n s on the body of the l i v i n g  animal.  75 The methods f o r the study of h a i r morphology were mostly those of Spence ( 1 9 & 3 )  a n d  - gave good r e s u l t s .  H a i r samples were  c o l l e c t e d from s p e c i f i e d r e g i o n s , care being taken t o see t h a t they were n o t m u t i l a t e d . H a i r l e n g t h was measured t o the n e a r e s t m i l l i m e t e r on a p l a s t i c measuring t h i s purpose.  scale.  The w o o l l y under h a i r s were i g n o r e d f o r  The h a i r diameters were measured under a compound  microscope w i t h c a l i b r a t e d o c u l a r  micrometer.  To observe g r o s s f e a t u r e s of the medulla and the c o r t e x of guard h a i r s the h a i r s were c l e a n e d by immersion  i n carbon  tetra-  c h l o r i d e , t r a n s f e r r e d t o xylene f o r 24- h r s and then p l a c e d d i r e c t l y i n t o t e c h n i c o n mounting medium.  The deer guard h a i r s had a  l a r g e medulla which was c l e a r l y observable even without  this  treatment. A technique suggested by Manby ( 1 9 3 2 ) was used i n the study of s c a l e p a t t e r n s . Negative impressions of the i n d i v i d u a l h a i r s were made i n a g e l a t i n - g l y c e r i n mixture.  The l i q u i f i e d medium i s spread on a  g l a s s s l i d e and a l l o w e d t o s o l i d i f y .  A f t e r i t s o l i d i f i e s the  h a i r whose s c a l e c a s t i s t o be prepared i s p l a c e d on i t .  A glass  s l i d e i s put on top of i t and the two s l i d e s t o g e t h e r , w i t h the h a i r i n between a r e warmed on a warming t a b l e .  When the g e l a t i -  n i z e d mounting medium becomes s o f t p r e s s u r e i s u n i f o r m l y a p p l i e d to the upper s i d e and subsequently both the s l i d e s a r e allowed t o cool.  When c o l d the upper s l i d e i s removed.  The h a i r which i s  now f i x e d i n the mounting medium i s removed by means of a f o r c e p , l e a v i n g the s c a l e Impression  behind.  76 S a t i s f a c t o r y h a i r s c a l e Impressions were a l s o obtained w i t h a method suggested by Dr. This consisted glue The  J . B e n d e l l of the Dept. of Zoology.  of spreading a t h i n l a y e r of q u i c k - d r y i n g  (Lapage's a i r p l a n e model cement) and  pressing  airplane  the h a i r on i t .  mounting medium d r i e s q u i c k l y , a f t e r which the h a i r i s removed,  leaving  the  The  s c a l e impression b e h i n d .  moult p a t t e r n s were s t u d i e d  moult p r o g r e s s was  on the l i v i n g a n i m a l .  The  r e c o r d e d on c y c l o s t y l e d sheets having a c e r v i d  o u t l i n e marked on i t . Observations Hair  characteristics  The  c h a r a c t e r i s t i c s as manifested by pelage are a suim  of the c h a r a c t e r i s t i c s of i n d i v i d u a l h a i r t y p e s . pertinent  to d i s c u s s  It i s  the major h a i r types present and  a c t e r i s t i c s before d i s c u s s i n g  the d i f f e r e n t coats and  total  therefore  their  char-  hair  p a t t e r n s of moult. Hair  types Large guard h a i r s These are long h a i r s up  scattered t i p s 15  over the body —  to 2 0 mm  l o n g and  h e a v i l y medullated and and  goats.  to 8 0 mm  about 2 cms  i n l e n g t h and apart.  uniformally  They possess b l a c k  have a s l i g h t l y crimped shape.  They are  m o r p h o l o g i c a l l y are a k i n to kemp of sheep  FIGURE 24 S k i n s u r f a c e view a t 269 mm stage. emerging l a r g e guard h a i r s .  Notice  FIGURE 25 S k i n s u r f a c e view a t 287 mm stage. Notice i n t e r m e d i a t e guard h a i r s a r e a l s o emerging a l o n g w i t h l a r g e guard h a i r s .  FIGURE 26 Fawn b i r t h coat h a i r a r r a y . types.  N o t i c e the h a i r  FIGURE 27  hair  Fawn w i n t e r coat guard h a i r a r r a y . types.  N o t i c e the  For e x p l a n a t i o n of a b b r e v i a t i o n s used please see Appendix IV, Page 2 l 4 v 1  78  79 Intermediate guard  hairs  These h a i r s a r e abundantly present I n the pelage and compose the b u l k of I t . ation.  They g i v e the pelage I t s c h a r a c t e r i s t i c c o l o u r -  They vary from 18 t o 4 4 mm i n l e n g t h and bear a b l a c k  t i p 3 to 5 ™  i n extent.  the l o n g e r h a i r s .  T h e i r form Is kemp l i k e — p a r t i c u l a r l y  H a i r s of v a r y i n g l e n g t h s and t h i c k n e s s occur  but a l l a r e l a r g e r than the h a i r s produced The  i n secondary  follicles.  s m a l l e r among them however may c o n c e i v a b l y a r i s e i n f i r s t  formed s e c o n d a r i e s . — and can be c a l l e d  These h a i r types a r e not •crimpy " T r a n s i t i o n a l " h a i r types.  1  kemp types  I n fawn b i r t h  coat t h i s type c o n s t i t u t e s the bulk of the undercoat. Woolly under h a i r s These a r e w o o l l y h a i r s which c o n s t i t u t e the under coat o f the a n i m a l . to 16/*- . Beard  They a r e t h i n and c u r l y — diameter v a r y i n g from 18/"They a r e non medullated.  type  These a r e l o n g h a i r s which d i f f e r from kemps i n not being crimpy.  They a r e s o f t and o f v a r i a b l e l e n g t h .  In Odocolleus  these h a i r s a r e r e s t r i c t e d c h i e f l y t o b l a c k patch on the t a i l , a x i l l a e , i n g u i n a l r e g i o n , p o s t e r i o r margin of rump. White t i p p e d h a i r s In a d d i t i o n t o these h a i r types the fawn b i r t h coat possesses white t i p p e d h a i r s .  These a r e o f the same l e n g t h and  type as i n t e r m e d i a t e guard h a i r s , but possess white e x t r e m i t i e s 5 t o 8 mm i n l e n g t h .  distal  These h a i r s a r e r e s p o n s i b l e  Adult summer coat  FIGURE 28.1 A d u l t summer coat h a i r a r r a y . types.  N o t i c e the h a i r  FIGURE 28.2 Close up of summer c o a t .  Adult winter  coat  FIGURE 29.1 A d u l t w i n t e r coat h a i r a r r a y . types.  N o t i c e the h a i r  FIGURE 29.2 Close up of w i n t e r c o a t . nature.  Notice i t s t h i c k  For e x p l a n a t i o n of a b b r e v i a t i o n s used p l e a s e see Appendix IV, Page 214,  81  82  f o r white spots on fawn b i r t h The of any  coat.  extreme t i p of a l l types of h a i r s i s p o i n t e d and  devoid  pigment.  Cortex, medulla and Observations  scutellation  were a l s o made on the c u t i c u l a r s c a l e p a t t e r n s  medulla and c o r t e x f e a t u r e s of these h a i r  types.  In fawn b i r t h coat a l l guard h a i r s presented  scale pattern  of i r r e g u l a r waved mosaic nature w i t h margins smooth and mediate.  (Terminology  The medulla was reduced  inter-  as per Spence ( 1 9 6 3 ) , Wildman (1937)  wide and of unbroken l a t t i c e type.  Cortex  )• was  on the s h a f t and c o u l d only be d i s t i n c t l y seen as a  t r a n s l u c e n t homogeneous mass a t the t i p and base of the h a i r . The white t i p p e d h a i r s had a g r e a t e r development of c o r t e x the medulla,  though wide, l a c k s i n t r a c e l l u l a r c a v i t i e s ,  undercoat  h a i r s a r e mostly medullated  medulla.  The  and possess  and  The  fragmental  s c a l e p a t t e r n present i s a v a r i a t i o n of the c o r o n a l  s c a l e s — i n v o l v i n g two  s c a l e s t h a t envelop  the h a i r s h a f t and  not  one as i n the case of t r u e c o r o n a l s c a l e p a t t e r n . In fawn w i n t e r coat the s c a l e s on guard h a i r s are of u l a r mosaic and not i r r e g u l a r waved mosaic.  The  irreg-  f e a t u r e s of  c o r t e x and medulla are the same as b e f o r e . In a d u l t summer coat the f e a t u r e s of c o r t e x and medulla are same.  The guard s c a l e p a t t e r n s are the same except  that at  d i s t a l e x t r e m i t i e s the margin changes from " i n t e r m e d i a t e " to close.  Woolly under h a i r s are m i s s i n g i n t h i s  coat.  In the a d u l t w i n t e r coat there i s g r e a t e r d i v e r s i t y .  The  f e a t u r e s of c o r t e x and medulla are same but s c u t e l l a t i o n v a r i e s .  83  FIG. 30  A N T E R O POSTERIOR DISTANCE B E T W E E N S C A L E MARGINS  AFTER SPENCE (1963)  FIG. 31  A R R A N G E M E N T OF HAIR S C A L E S AFTER SPENCE (1963)  84  Large guard h a i r s b a s i c a l l y have i r r e g u l a r mosaic s c a l e s , margin smooth, i n t e r m e d i a t e t o d i s t a n t — i n r e s t of the h a i r margin i s smooth — i n t e r m e d i a t e t o near.  The Intermediate guard  hair  s c a l e s a r e r e g u l a r mosaic, margin smooth and d i s t a n t but i n d i s t a l end margin becomes smooth, i n t e r m e d i a t e t o near. The beard type have i r r e g u l a r waved mosaic s c a l e s w i t h margins smooth and i n t e r m e d i a t e , i n the mid p a r t of the h a i r as w e l l as d i s t a l p a r t margin may be i n t e r m e d i a t e t o c l o s e .  shaft The  w o o l l y h a i r s have s c a l e s as b e f o r e and a r e non m e d u l l a t e d . I n fawn b i r t h coat the h a i r s a r e s o f t e r and of s m a l l e r diameter.  The number o f non medullated f i b r e s i s very low. The  s m a l l e r h a i r types bear a fragmental type of medulla as opposed to the wide l a t t i c e d type p r e s e n t i n guard h a i r s . fawn undercoat all  Most of the  i s made up of t r a n s i t i o n a l h a i r types which a r e  medullated. In fawn w i n t e r coat the h a i r s have a t t a i n e d l a r g e r  and l e n g t h .  diameter  The t r u e non medullated w o o l l y h a i r s a r e present i n  l a r g e numbers and c o n s i s t o n l y of c o r t e x and c u t i c l e . In a d u l t summer coat i n c o n t r a s t t o a d u l t w i n t e r coat the h a i r s a r e of s m a l l e r diameter and g r e a t e r l e n g t h . undercoat  The w o o l l y  i s missing.  I n a d u l t w i n t e r coat the h a i r s a r e s h o r t e r but of g r e a t e r diameter,  than those i n a d u l t summer c o a t .  and o f l a r g e r diameter,  The medulla i s wide  The s c a l e p a t t e r n i s g r e a t l y v a r i a b l e .  A w e l l developed w o o l l y undercoat  i s present.  G e n e r a l l y i n medullated h a i r s i t can be s a i d that areas w i t h l a r g e r diameter have a r e g u l a r mosaic s c a l e p a t t e r n with margins smooth and d i s t a n t , whereas i n h a i r s w i t h s m a l l e r diameter the  85 s c a l e s become i r r e g u l a r mosaic t o i r r e g u l a r waved mosaic w i t h smooth margins and d i s t a n c e between margins v a r y i n g from i n t e r mediate t o near. diameter  I n woolly under h a i r s there i s no change of  i n the main h a i r s h a f t consequently  s c a l e p a t t e r n remains  uniform. Hausman (1930), Mahal e t a l (1951) have made some t i o n s on s c a l e p a t t e r n i n a n i m a l s .  observa-  The g e n e r a l c o n c l u s i o n being  t h a t t h e r e i s no r e l a t i o n s h i p o f any of the a t t r i b u t e s i . e . number of s c a l e s per u n i t l e n g t h , average v i s i b l e s c a l e h e i g h t e t c t o breed or wool type. Colouration The  other important a s p e c t of h a i r i s i t s c o l o u r a t i o n .  That o f the d i s t a l h a l f of the t o t a l h a i r l e n g t h i s important i n determining the pelage c o l o u r a t i o n . The  extreme t i p of most h a i r s i s g e n e r a l l y c o l o u r l e s s .  T h i s i s f o l l o w e d by a b l a c k c o l o u r e d zone, which r e a l l y t u t e s the v i s i b l e p a r t of the h a i r t i p .  consti-  This region i s followed  by zones o f w h i t i s h yellow, r e d d i s h yellow or grey depending on the nature o f h a i r c o a t .  The c o l o u r v a r i a t i o n i n d i f f e r e n t  coats  or over d i f f e r e n t body r e g i o n s o f the same coat as they e x i s t a r e caused  by presence  o r absence of these c o l o u r e d zones, or changes  i n t h e i r extent i n the d i s t a l end o f the h a i r .  These a r e d i s c u s s e d  i n a subsequent chapter i n d e t a i l . The b i r t h coat of fawns and the summer coat o f a d u l t s show resemblances t o each o t h e r .  The v i s i b l e p a r t of h a i r s i n the  pelage c o n s i s t of a b l a c k t i p , f o l l o w e d by a r e d d i s h yellow h a i r shaft.  The b a s a l p a r t o f each h a i r i s l i g h t c o l o u r e d ending  plgmentless a r e a of the b u l b .  The l a r g e guard h a i r s have  ina  86 proportionately longer black t i p s .  The beard type h a i r s are of  uniform c o l o u r a t i o n e i t h e r b l a c k or w h i t e . In  the w i n t e r coat of fawns and a d u l t s the b l a c k t i p e d zone  i s f o l l o w e d by a y e l l o w i s h white zone.  This i n turn i s followed  by g r e y i s h c o l o u r a t i o n f a d i n g towards the base. guard h a i r s the  In the l a r g e  ' y e l l o w i s h zone i s r e p l a c e d by a ' r e d d i s h y e l l o w ' 1  zone of g r e a t e r l e n g t h .  Thus the c o l o u r a t i o n here i s more remi-*-  n i s c e n t of the summer coat and i n d i c a t e s that even i n w i n t e r coat the melanocyte  a c t i v i t y i n l a r g e guard h a i r f o l l i c l e s  from the a d j o i n i n g h a i r f o l l i c l e s . may  i s different  The fawn w i n t e r coat h a i r s  be completely b l a c k c o l o u r e d over the e n t i r e l e n g t h .  As before  the beard type h a i r s are e i t h e r completely b l a c k or white. The w o o l l y under h a i r s which occur i n bulk i n the w i n t e r coat are not v i s i b l e e x t e r n a l l y .  When a c t i v e l y growing  g r e y i s h but when r e s t i n g are v i r t u a l l y In  they are  colourless.  the course of t h i s study o b s e r v a t i o n s were made on h a i r  l e n g t h , diameter and the extent of the d i f f e r e n t c o l o u r zones, i n the l a r g e and i n t e r m e d i a t e guard h a i r s , i n d i f f e r e n t body r e g i o n s of the animal and i n d i f f e r e n t c o a t s . attempt  T h i s i s i n an  t o put i n q u a n t i t a t i v e terms, what t h e i r  a r e and how  interrelations  they a f f e c t the pelage c o l o u r a t i o n i n d i f f e r e n t body  r e g i o n s and i n d i f f e r e n t c o a t s . The c o l o u r a t i o n of the pelage as a whole does not s t a t i c d u r i n g the course of the y e a r .  remain  The w i n t e r coat i n i t s  e a r l y phases p r e s e n t s a s t e e l y grey appearance but w i t h continued h a i r growth and environmental e f f e c t t h i s fades t o a y e l l o w i s h grey c o l o u r a t i o n , which i s r e t a i n e d most of the time.  Just  to  appearance.  shedding the coat has a w e l l worn l o o k and a faded  prior  87 The  summer c o a t of a d u l t s I s r e d d i s h brown when i n prime but  fades t o p a l e r shades before moult. undercoat  The upcoming g r e y i s h w o o l l y  i n the l a t e r p a r t s o f the summer a l s o c o n t r i b u t e s , t o  changing i n c o l o u r t o a g r e y i s h shade. Hayman and Nay (i960) have c l a s s i f i e d stages i n a c a t t l e coat d u r i n g the course of the year, on the b a s i s o f "appearance of  the c o a t , the number o f l o o s e f i b r e s , t h e i r degree  and the p r o g r e s s o f shedding".  o f looseness,  Each stage i s g i v e n a s c o r e , t h e r e  b e i n g twelve stages and the score o f the l a s t one b e i n g twelve. These stages cannot be a p p l i e d " i n t o t o " t o deer. i n c a t t l e a percentage i s n o t so i n deer.  Whereas  o f h a i r s i s being shed a l l the time,  this  I n c o n t r a s t t o the c a t t l e , passage of a hand  over the deer body when h a i r s a r e i n r e s t i n g stages h a r d l y b r i n g s about any l o s s of h a i r s even though the h a i r s can be p l u c k e d easily. Coat d e s c r i p t i o n and p a t t e r n of moult We have a l r e a d y r e f e r r e d e a r l i e r t o the f a c t t h a t the b l a c k t a i l deer i n course of i t s l i f e c y c l e has f o u r types of c o a t s . The c h a r a c t e r i s t i c s of h a i r types c o n s t i t u t i n g these c o a t s have a l s o been r e f e r r e d t o . Now I s h a l l endeavour t o d e s c r i b e the f e a t u r e s of these coats as they occur on the animals and the moult processes by which one coat type g i v e s way t o another. Fawn b i r t h coat The b l a c k t a i l fawns a r e born i n summer mostly i n May and June.  The coat w i t h which they a r e born and which i s r e t a i n e d  88  distal end FIG 32.1 D I F F E R E N T BODY REGIONS OF T H E B L A C K TAIL DEER. SIDE VIEW  FIG. 32.2 HEAD, FRONT VIEW  .FIG. 32.3 POSTERIOR VIEW  89 till  i t s moult i n l a t e summer or autumn i s very s o f t and g i v e s  the young a f l u f f y appearance.  The s o f t n e s s of the coat i s  r e l a t e d t o f i n e n e s s o f the h a i r types c o n s t i t u t i n g the coat, whereas the f l u f f i n e s s may be c o r r e l a t e d w i t h the g r e a t e r  folli-  c u l a r d e n s i t y and the d i s p a r i t y i n the l e n g t h s o f l a r g e guard h a i r s v i s a v i s o t h e r s i n the pelage. The  coat i s brownish i n c o l o u r , darker d o r s a l l y , f a d i n g  l a t e r a l l y t o l i g h t e r shades.  There a r e two p a r a l l e l rows of  white spots on the back, the o t h e r s being s c a t t e r e d along the f l a n k s and t h i g h s .  The h a i r s on the f a c e and the d i s t a l ends o f  the limbs a r e s h o r t e r than those over the r e s t of the body. h a i r s o c c u r r i n g i n the a x i l l a r ,  i n g u i n a l , rump and t a i l  a r e i n the same r e l a t i o n s h i p l o n g e r . t h e i r d e n s i t y appears l e s s .  The  regions  In the a x i l l a and inguinum  T h e . t a i l c h a r a c t e r i s t i c a l l y bears a  black t i p . I n c o n t r a s t to the brownish shade present d o r s a l l y the h a i r s o c c u r r i n g i n the neck, chest, and abdomen a r e l i g h t e r i n c o l o u r , . Those o c c u r r i n g i n the a x i l l a ,  i n g u i n a l region, v e n t r a l side of  the t a l l and p o s t e r i o r margin o f the rump a r e w h i t e . H a i r s i n the v i c i n i t y of the t a r s a l and m e t a t a r s a l  glands  a r e l o n g e r , c o a r s e r , and e r e c t i l e . Moult i n the fawn b i r t h  coat  There was some v a r i a t i o n i n the i n i t i a t i o n and completion of. the moult of the fawn l e a d i n g to i t s shedding coat and a q u i s i t i o n of the w i n t e r c o a t . in  of the b i r t h  T h i s g e n e r a l l y begins  the l a t e summer and i s completed i n October, by which time the  a d u l t s a l s o have assumed the w i n t e r  coat.  90 Moult i n the fawn can "be "best d e s c r i b e d i n terms of f o u r stages which f o l l o w each other i n a time sequence and a r e easy to distinguish.  These stages have been c a t e g o r i z e d on the b a s i s of  the fawn's appearance as m o d i f i e d by the moult i n p r o g r e s s . Stage I  (July)  The h a i r s c o v e r i n g the ear pinnae are shed f i r s t , ears a naked appearance f o r a w h i l e . surrounding  Simultaneously  g i v i n g the  the h a i r s  the eyes are shed and r e p l a c e d by cream-coloured h a i r s  which d i s t i n c t l y demarcate t h i s a r e a .  H a i r s a r e then r e p l a c e d on  cheeks, f r o n t p a r t of the f a c e and forehead.  The  l a s t p a r t s of  the head t o moult a r e the i n n e r s i d e s of the ears and here the dark c o l o u r e d margins l o s e the h a i r s f i r s t . At the end of t h i s stage the head has completely i n t o the w i n t e r pelage. is  moulted  I n i t i a l l y i t has a g l o s s y appearance and  i n d i s t i n c t c o n t r a s t to the b i r t h coat s t i l l p r e v a l e n t on  the  body. Stage I I (August) Moult then proceeds on the under s i d e of the neck and w h i l e the h a i r s on the body are r e l a t i v e l y  intact.  T h i s phase i s f o l l o w e d by the g e n e r a l l o s s of the nature  chest,  of the coat as the white t i p p e d h a i r s are l o s t .  h a i r s shed e a r l i e r than many others i n the pelage.  spotted  fhu§  t  h  i  f  i  This i s  i n t e r e s t i n g because none of the other i n t e r m e d i a t e guard h a i r s are b e i n g shed a t t h i s s t a g e .  The mechanism of c o n t r o l over  a p p a r e n t l y p r e c i s e l o c a l moulting  such  i s not known.  Towards the end of t h i s phase there i s c o n s i d e r a b l e l o s s of  Moult stages fawn b i r t h t o fawn w i n t e r c o a t  FIGURE 33.1 Fawn In b i r t h c o a t .  FIGURE 3 3 . 2 Moult stage 1.  Head has moulted, FIGURE 3 3 . 3  Moult stage I I . The neck i s moulting but b i r t h coat i s i n t a c t on most of the body.  FIGURE 3 3 . 4 Moult stage I I I . The white spots have a l l disappeared but b i r t h coat i s l o o s l y p r e s e n t over the body.  FIGURE 34 Fawn i n w i n t e r c o a t .  92  93 h a i r over the body.  I t has no p a t t e r n but i s g e n e r a l .  The h a i r s  most a f f e c t e d a r e the t r a n s i t i o n a l types forming the b u l k of the under c o a t .  At the end o f t h i s stage the fawn shows a thinned  out appearance w i t h o n l y l a r g e r and i n t e r m e d i a t e guard  hairs  remaining. Stage I I I  (September)  The upcoming w i n t e r coat i s seen through the t h i n n e d out b i r t h coat.  The remaining b i r t h coat h a i r s a r e now shed  direct-  i o n a l l y i n a cauded wave. Stage IV  (Oc t o b e r )  The fawn i s now i n f u l l w i n t e r coat, except t h a t the o l d b i r t h coat h a i r s a r e s t i l l present i n the v i c i n i t y of t a r s a l and m e t a t a r s a l glands, these a r e p r o g r e s s i v e l y r e p l a c e d . Fawn w i n t e r c o a t By October end the fawns a r e i n t h e i r f u l l w i n t e r c o a t . T h i s grey coat g r e a t l y resembles  the w i n t e r c o a t of the a d u l t .  The h a i r s have s m a l l e r diameter and l e n g t h , and a r e s o f t e r those o f a d u l t w i n t e r c o a t .  A w o o l l y undercoat  than  i s present here.  Other d e t a i l s of h a i r and t h e i r t o p o g r a p h i c a l v a r i a t i o n a r e the same as i n the a d u l t . Moult from fawn w i n t e r coat t o a d u l t summer coat The y e a r l i n g animal on moulting from fawn w i n t e r coat assumes a summer coat i d e n t i c a l t o t h a t o f the a d u l t . of  —  The process  moult c o u l d not be documented as the experimental animals  had  94 b i t t e n o f f t h e i r coat t o a g r e a t extent and no meaningful o b s e r v a t i o n c o u l d be made. L i n s d a l e and Tomich (1953) s t a t e t h a t i n mule deer y e a r l i n g s the s p r i n g moult s t a r t s l a t e r than i n the a d u l t s and extends f o r a longer p e r i o d .  The moult i s s a i d t o have no p a t t e r n but i s mani-  f e s t e d by g r a d u a l replacement of o l d h a i r s by the new coat growing underneath.  T h i s i s i n c o n t r a s t t o a d u l t s p r i n g moult i n which a  p a t t e r n can be d i s c e r n e d . Adult summer coat T h i s coat i s very d i f f e r e n t from the a d u l t w i n t e r The  coat.  standard h a i r types, t h e i r morphology and c o l o u r a t i o n have  a l r e a d y been r e f e r r e d t o . In g e n e r a l the summer coat h a i r s a r e l o n g e r and s t r a i g h t e r than t h e i r winter c o u n t e r p a r t s . form.  The kemps possess much l e s s wavy  The percentage of h a i r s below 30 mm l e n g t h i s much l e s s  i n the w i n t e r c o a t .  The h a i r diameter i s a l s o s m a l l e r and l e s s  v a r i a b l e i n r e l a t i o n t o h a i r l e n g t h than i n the winter c o a t . summer pelage  than  The  i s y e l l o w i s h r e d i n c o n t r a s t t o y e l l o w i s h grey o f  the w i n t e r c o a t .  The p a r t s of the h a i r r e s p o n s i b l e f o r i t a r e  the v i s i b l e d i s t a l h a l f of the h a i r c o n s i s t i n g o f the b l a c k t i p and the r e d d i s h y e l l o w h a i r s h a f t . The  summer coat i s a l s o c h a r a c t e r i z e d by the l a c k of the  w o o l l y undercoat.  Thus there i s o p p o r t u n i t y f o r g r e a t e r a i r  c i r c u l a t i o n over body, and presumably g r e a t e r o p p o r t u n i t y f o r d i s s i p a t i o n of body heat. H a i r s on the lower l e g s a r e longer on the forward than elsewhere.  surface  I n the v i c i n i t y of the t a r s a l and m e t a t a r s a l  gland  95 the h a i r s are rougher and c o a r s e r .  The h a i r s o c c u r r i n g on the  underside of the t a i l , p o s t e r i o r s i d e or the rump and of  the u r o g e n i t a l a r e a as w e l l as i n a x i l l a and  and white.  The  i n periphery  inguinum, are l o n g  t a i l c a r r i e s a b l a c k spot d o r s a l l y .  Moult from a d u l t summer to a d u l t w i n t e r - c o a t T h i s takes p l a c e d u r i n g l a t e summer to e a r l y autumn and l a s t s from August to October.  The g e n e r a l d i r e c t i o n i s from head  towards t a i l i . e . cauded. The moult i s f i r s t a v e r y t h i n coat of h a i r . the pinnae are f u l l y  n o t i c e d i n the e a r s , which d o r s a l l y  bear  A t h i c k e r coat grows i n i t s p l a c e and  covered.  The next r e g i o n to moult i s head.  The  l o s s of h a i r s on the  f a c e i s d i f f u s e , but where the h a i r s are l o n g e r on the head the moult t r a c t s appear;  One  of these moves upwards through  between the eyes and the ear pinnae and touches the neck.  The  meets the neck.  the r e g i o n  the d o r s a l s i d e of  other t r a c t moves sidewards a l o n g the cheek t i l l i t The l o s s of h a i r s on the lower  jaw a l s o takes  p l a c e about t h i s time but i s d i f f u s e . On the neck the shedding undersurface.  The  continues a l o n g the s i d e ,  summer h a i r s present d o r s a l l y i n the neck r e g i o n  undergo a g r a d u a l t h i n n i n g and are amongst the l a s t to be  and  summer h a i r s  shed. While the neck i s l o s i n g h a i r s the shoulders and the ante-  r i o r r e g i o n of the back a l s o begin to shed.  On shoulders  the  t h i n n i n g begins i n the c e n t r a l r e g i o n and g r a d u a l l y spreads out to meet the neck, back, f l a n k s and chest r e g i o n .  The h a i r  shedding  on the shoulder a r e a continues onto the f l a n k r e g i o n i n a d i a g o n a l manner and proceeds towards the abdomen.  Simultaneously  hair  loss  FIGURE 35 A d u l t i n summer c o a t .  Moult from a d u l t summer coat t o a d u l t w i n t e r c o a t  FIGURE 3 6 . 1 Moult stage I .  The ears have moulted.  FIGURE 3 6 . 2 Moult stage I I . Moult p r o g r e s s i n g The body i s m o u l t i n g .  cauded,  FIGURE 3 6 . 3 Moult stage I I I . remain t o be moulted.  Only the d i s t a l end of l e g s  97  FIG. 35  FIG.36.2  FIG. 36  FIG. 36.1  STAGE 2  FIG. 36.3  STAGE I  STAGE 3  ADULT SUMMER TO ADULT WINTER MOULT STAGES  98 on the back i s p r o g r e s s i n g s t e a d i l y caudad.  The summer h a i r s on  the upper s i d e of the f l a n k s are a l s o shed about t h i s time  (late  August) and a stage i s reached when the summer h a i r s on the body remain i n the r e g i o n of the c h e s t , abdomen, the limbs and p o s t e r i o r p a r t of the back. The wave of moult now  proceeds from the shoulders,  first  a l o n g the f r o n t of the f o r e l e g , then t o the p o s t e r i o r f a c e and toward the hoof where i t i s d i f f u s e and g r a d u a l .  T h i s takes p l a c e  i n September. The l o s s of summer h a i r s i n the chest r e g i o n takes p l a c e i n l a t e August.  The shedding proceeds between the f o r e l e g s  towards  the abdomen where a g a i n moult becomes d i f f u s e . I n e a r l y August the c e n t r a l p a r t of t h i g h s b e g i n t o shed hairs.  T h i s patch e n l a r g e s t o meet d o r s a l l y the back and  l y the f l a n k s .  lateral-  The p o s t e r i o r margin of t h i s patch i s demarcated  by the elongated h a i r s i n the rump r e g i o n , which are amongst the l a s t t o be shed. D i s t a l l y i n the h i n d l e g moult d i f f e r s from that of the f o r e l e g s as i t proceeds a l o n g the s i d e s l e a v i n g the summer h a i r s more or l e s s i n t a c t i n the f r o n t p a r t and a l s o i n the p o s t e r i o r margin and i n the a r e a surrounding t a r s a l and m e t a t a r s a l glands and around hooves.  The l o s s of h a i r i n these p l a c e s i s v e r y  g r a d u a l and d i f f u s e and may  continue even i n t o e a r l y October.  The l o n g white h a i r s on the rump are shed g r a d u a l l y from the v i c i n i t y o f the feail downwards i n e a r l y September.  The white  h a i r s b o r d e r i n g the a n a l and u r o g e n i t a l a r e a a r e shed e a r l i e r than those of the p o s t e r i o r margin of rump and here the trend of shedding i s ventrad.  9 9  The  shedding  o f the h a i r s on t a i l i s d i f f u s e and appears t o  take p l a c e d u r i n g summer. Adult w i n t e r  By f a l l the t a l l has new h a i r s .  coat  The w i n t e r coat o f the b l a c k t a i l  i s much denser  summer coat because there i s w e l l developed  than the  w o o l l y undercoat.  In  c o n t r a s t t o the r e d d i s h yellow t i n g e o f the summer coat i n i t s e a r l y stages p r e s e n t s a s l e e k m e t a l l i c grey appearance  (October),  but soon fades t o a p a l e r shade. The  forehead r e g i o n i s demarcated on i t s s i d e s by two dark  l i n e s which descend and meet i n between the eyes.  The presence o f  g r e y i s h h a i r s around the eyes and i n f r o n t of the snout g i v e a d i s t i n c t mask l i k e appearance present only i n the w i n t e r c o a t .  The  h a i r c o l o u r a t i o n v a r i e s but the h a i r types except f o r the wool f i b r e s and t h e i r d i s t r i b u t i o n on the body a r e as i n summer. The  i n d i v i d u a l h a i r s however have l a r g e diameter  and a  l e n g t h r e l a t i v e l y s h o r t e r ( r e f e r t o l a t e r t a b l e s ) than t h a t i n the summer c o a t .  The kemps a r e more wavy i n form.  s h o r t h a i r s i s g r e a t e r than i n summer c o a t .  The percentage of  The wavy nature of  kemps a s s i s t s i n accommodating the w o o l l y undercoat  properly —  both together c o n s t i t u t i n g a good i n s u l a t i n g l a y e r d n the body i n winter. Moult from a d u l t w i n t e r coat t o a d u l t summer coat At our l a t i t u d e t h i s moult begins i n m i d - A p r i l and ends by l a t e June and f o l l o w s a p a t t e r n d i f f e r e n t from t h a t of the f a l l moult. G e n e r a l l y the f l a n k s a r e the f i r s t  t o shed, and patches  having new summer coat a r e formed on both s i d e s .  This  culminates  A d u l t w i n t e r t o a d u l t summer coat moult  FIGURE 37 Adult i n winter coat.  FIGURE 38.1 Moult stage I .  The moult s t a r t s on the body.  FIGURE 38.2 Moult stage I I . caudad.  Moult spreads cephalad and  FIGURE 38.3 Moult stage I I I . Moult complete except f o r patch under the t h r o a t , and some h a i r s on h i n d l e g d i s t a l end.  101  FIG. 3 8 . 2 FIG. 38  STAGE 2  FIG. 38.3  STAGE 3  ADULT WINTER TO ADULT S U M M E R MOULT S T A G E S  102 i n a stage when the animals appear t o have moulted a l o n g the f l a n k s and t o some extent d o r s a l l y .  centrally  The shedding o f  s h o r t h a i r s on the f a c e as w e l l as on the d i s t a l ends of l e g s i s taking place d i f f u s e l y .  The new h a i r s a r e of the same c o l o u r as  the o l d h a i r s and have a l r e a d y grown t o some l e n g t h "before the o l d h a i r s a r e shed.  The f l a n k moult i s completed by e a r l y  June.  On the body the m o u l t i n g now proceeds i n two d i r e c t i o n s cephalad a l o n g the neck and caudad a l o n g the rump.  —  Along the  neck the h a i r s a r e f i r s t l o s t on the d o r s a l and l a t e r a l s i d e s and those on the lower s i d e a r e amongst l a s t t o be shed. i n June.  T h i s occurs  P o s t e r i o r l y on the t h i g h s the h a i r s a r e shed and moult-  i n g proceeds downwards.  The w i n t e r h a i r s on the p o s t e r i o r  margin  of the rump a r e among the l a s t t o shed and a r e moulted v e n t r a d . The h a i r s around the a n a l and u r o g e n i t a l r e g i o n moult e a r l i e r than this  (mid-June).  The abdomen moults d i f f u s e l y i n May.  H a i r s on  the p o s t e r i o r margin o f the h i n d limbs and a c r o s s the t a r s a l and m e t a t a r s a l glands a r e a g a i n the l a s t t o be shed. In e a r l y June the ears a l s o shed t h e i r h a i r s and d u r i n g the r e s t of summer coat they a r e covered s p a r s e l y by s m a l l h a i r s g i v i n g the pinnae a bare appearance.  Gross i n s p e c t i o n of the ears  r e v e a l a r i c h b l o o d supply and i t i s tempting t o suggest t h a t they are important i n t h e r m o r e g u l a t i o n .  I f t h i s i s so the almost  naked c o n d i t i o n i n summer and h e a v i l y f u r r e d s t a t e i n w i n t e r has adaptive  significance.  103  Summary The major pelage types i n the l i f e h i s t o r y o f the b l a c k t a i l deer have been i n v e s t i g a t e d and the process of moulting  from  one type i n t o another has been documented. The h a i r s o f t h i s s p e c i e s can be d i s t i n g u i s h e d as f o l l o w s : l a r g e guard h a i r s , i n t e r m e d i a t e guard h a i r s , and beard type  (long  and s o f t guard h a i r s i n Odocolleus r e s t r i c t e d o n l y t o t a i l ) . These a r i s e i n primary f o l l i c l e s . follicles  The f i r s t formed  secondary  g i v e r i s e t o s m a l l but medullated h a i r s i . e . of  transi-  t i o n a l type and the l a t e r formed s e c o n d a r i e s t o the non medullated w o o l l y under h a i r s — forming the animals undercoat. formed s e c o n d a r i e s and some p r i m a r i e s produce  The f i r s t  s p e c i a l medullated  h a i r s ; w i t h w e l l developed proximal end but t h i n and wavy d i s t a l end.  These have been c a l l e d t r a n s i t i o n a l t y p e s .  c o n s t i t u t e the undercoat follicles  i n fawn b i r t h c o a t .  They i n f a c t  I n a d d i t i o n primary  i n the fawn b i r t h coat a t p l a c e s g i v e r i s e t o white  tipped h a i r s .  Thus the primary f o l l i c l e s a r e capable of g i v i n g  r i s e t o many h a i r t y p e s . The h a i r s c a l e c h a r a c t e r i s t i c s depend on h a i r dimension and not on h a i r type. diameter.  They seem t o be v a r y c l o s e l y w i t h the h a i r  The w o o l l y under h a i r present a v a r i a t i o n of c o r o n a l  s c a l e type; and a r e of uniform diameter. i s however g r e a t l y v a r i a b l e .  The guard h a i r  Their scale pattern varies  diameter from  I r r e g u l a r mosaic t o i r r e g u l a r waved mosaic w i t h smooth margins and the i n t e r m a r g i n a l d i s t a n c e v a r y i n g from d i s t a n t , i n t e r m e d i a t e ( c l o s e ) , t o near.  The a d u l t winter coat h a i r s :present g r e a t e r  v a r i a b i l i t y i n scale pattern.  104 The h a i r s of fawn b i r t h coat resemblecoat i n c o l o u r a t i o n .  those of a d u l t summer  The fawn w i n t e r coat possesses t r u e woolly-  undercoat, Snd resembles  adult winter coat.  The a d u l t summer  coat h a i r s a r e l o n g e r , s t r a l g h t e r and l e s s crimpy coat h a i r s .  I t l a c k s woolly undercoat and has a c h a r a c t e r i s t i c  colouration. darker.  than the w i n t e r  The a d u l t w i n t e r coat h a i r s a r e s h o r t e r , t h i c k e r and  There i s a l s o g r e a t e r v a r i a b i l i t y i n t h e i r l e n g t h .  The pelage c o l o u r a t i o n depends on the c o l o u r a t i o n of the v i s i b l e e x t r e m i t i e s of guard h a i r s .  These as w e l l as other  morphometric d e t a i l s of h a i r s have been covered i n a separate chapter. The b l a c k t a i l deer moults  twice a year i . e . i n s p r i n g and  a g a i n i n l a t e summer t o e a r l y autumn.  The fawn b i r t h coat begins  to be shed by J u l y and the fawn w i n t e r coat i s assumed by October. The b i r t h coat moult takes p l a c e i n d i s t i n c t i v e stages and the t r e n d i s caudad. of y e a r l i n g s observed.  White spots a r e l o s t e a r l y .  ( i . e . fawn w i n t e r t o a d u l t summer c o a t ) c o u l d not be  The a d u l t w i n t e r moult begins on the f l a n k s and spreads  both cephalad and caudad. caudad.  The s p r i n g moult  The shedding of the summer coat i s  The w o o l l y undercoat o f non medullated h a i r moults i n  d i f f u s e f a s h i o n o n l y once a year i . e . i n May.  105 Chapter V  THE HAIR CYCLE OF THE BLACK TAIL DEEH  INTRODUCTION The moult i s o n l y a t e r m i n a l stage of the h a i r c y c l e and t o a p p r e c i a t e the phenomenon of h a i r replacement hair cycle i n i t s e l f  p r o p e r l y the annual  has t o be c l e a r l y understood.  cance of t h i s has been adequatly s t r e s s e d by L i n g Ryder (1964).  The  signifi-  (19&5)» and by  The best way t o do t h i s i s t o sample the s k i n a t  r e g u l a r i n t e r v a l s and r e c o r d the changes i n the h a i r f o l l i c l e i n the course of the y e a r .  Nothing i s known of t h i s phase of the  s e a s o n a l l y c y c l i c a l b i o l o g y of any c e r v i d . MATERIAL AND METHODS Two animals were used f o r t h i s study and s k i n b i o p s y samples were c o l l e c t e d every f o r t n i g h t by means of t r e p h i n e . of  the t r e p h i n e have been d i s c u s s e d by L i n g  The d e t a i l s  (1965).  The animals were immobilized by u s i n g S u c c i n y l c h o l i n e chloride  (ANECTINE).  The dosage f o r deer was worked out by  Zoology Dept. i n course of e a r l i e r r e s e a r c h and was .0013 c c / l b of animal weight.  As the animals were weighed every week c o r r e c t  dosage c o u l d be a d m i n i s t e r e d w h i l e sampling.  The dosage was  a d m i n i s t e r e d by t u b e r c u l i n s y r i n g e , u s i n g d i s p o s a b l e n e e d l e s . The response i n the animal was v a r i a b l e , .  W9 i n p a r t i c u l a r  o f t e n had d i f f i c u l t y b r e a t h i n g a f t e r c o l l a p s i n g on the ground and o f t e n r e q u i r e d a r t i f i c i a l r e s p i r a t i o n .  Subsequent manipula-  t i o n of the dosage r e v e a l e d t h a t even $0% of p r e s c r i b e d dosage  FIGURE 39  The t r e p h i n e used f o r t a k i n g s k i n b i o p s y sampling.  FIGURE 40 F o r t n i g h t l y sampling s i t e s . The number denotes the "sample" number as w e l l as i t s l o c a t i o n on the animal's body.  FIG 39 1  5  9  13  17  4  15  19  23  27  22  8  II  25  30  29  26  12  7  21  28  24  20  16  3  18  14  10  6  2  FIG 40  108  was  s u f f i c i e n t to Immobilize t h i s i n d i v i d u a l and  modified  accordingly.  not c r e a t e  was  For the other animal r e g u l a r dosage d i d  problems.  A sampling programme was successive  a l s o drawn up to ensure t h a t  sampling s i t e s were not a d j o i n i n g each o t h e r .  were taken from the t h i g h , and i n 70% a l c o h o l . equal p a r t s .  One  other p a r t was  f i x e d i n BOUIN'S f l u i d ,  Subsequently each sample was p a r t was  Samples  and  stored  divided into  two  s e c t i o n e d l o n g i t u d i n a l l y i . e . perpen-  d i c u l a r to the s u r f a c e , along  at  the dosage  the plane of the h a i r s and  sectioned across  the s u r f a c e .  8 / ^ were s t a i n e d w i t h haematoxylin and  The  the  sections  cut  eosin.  OBSERVATIONS On the t h i g h the main body pelage c o n s i s t s of three types of hairs.  The  l a r g e and  under h a i r s .  intermediate  guard h a i r s and  the w o o l l y  In a d u l t animals a l l growing c e n t r a l primary  c l e s are of approximately the same l e n g t h and  there  folli-  i s less  l e n g t h v a r i a t i o n than i n these h a i r s i n the n a t a l pelage. The  follicles  stages d u r i n g cle  the h a i r c y c l e .  i s formed and  anagen.  i n a l l species  the new  The  s t u d i e d assume the  phase d u r i n g which the  folli-  h a i r i s produced has been termed the  T h i s envolves t r a n s f o r m a t i o n  i n t o an a c t i v e f o l l i c l e .  following  The  of the r e s t i n g f o l l i c l e  f o l l i c l e base i s c l a v a t e  and  encloses  the dermal p a p i l l a w h i l e the r e s t of the newly forming  follicles  can be d i s t i n g u i s h e d i n t o an e x t e r n a l r o o t sheath and  c e n t r a l mass of u n d i f f e r e n t i a t e d c e l l s . normal l a y e r s are d i f f e r e n t i a t e d and ing  new  hair.  Subsequently a l l the  the f o l l i c l e  s t a r t s produc-  When the f o l l i c l e has reached i t s f u l l p e r i o d  of  a  109 growth i t e n t e r s i n t o catagen stage.  This i s a t r a n s i t i o n a l short  l i v e d p e r i o d , l e a d i n g to the r e s t i n g stage of the f o l l i c l e , telogen.  In catagen the bulb becomes c o l l a p s e d and the  p a p i l l a i s not t i g h t l y h e l d by the f o l l i c l e base.  dermal  The h a i r base  forms a c l u b e n c l o s e d i n a sac of e x t e r n a l r o o t sheath and p o r t i o n of the f o l l i c l e below i t degenerates  namely  the  i n t o a s t r a n d of  cells.  The h a i r and the f o l l i c l e p a r t remaining migrate upwards t i l l r e a c h sebaceous gland l e v e l , where they remain. t e l o g e n or r e s t i n g s t a g e . will  During subsequent  they  T h i s i s the  h a i r c y c l e the  follicle  be r e a c t i v a t e d , o l d h a i r shed and by a r e p e t i t i o n of process  a l r e a d y d e s c r i b e d new  hair w i l l  be produced.  d i s c u s s e d here undergo these stages but due  A l l the  follicles  t o the very s h o r t  nature of i t s d u r a t i o n catagen has not been observed f u l l y To understand  here.  the events i n v o l v e d i n the h a i r c y c l e of  my  animals l e t us b e g i n w i t h the w i n t e r coat i n the r e s t i n g stage. The w i n t e r coat a t t a i n s f u l l growth by e a r l y November and  reaches  r e s t i n g stage then. The h i s t o l o g i c a l examination of the m a t e r i a l r e v e a l s t h a t by e a r l y March the guard h a i r f o l l i c l e s l a r g e guard h a i r f o l l i c l e s  have s t a r t e d growing,  presumably s t a r t i n g f i r s t , and  the f i r s t emergent summer coat h a i r s .  the possess  These are s c a t t e r e d a l l over  the body, r e a c h i n g l e n g t h s which makes them protrude i n A p r i l  over  the e x i s t i n g w i n t e r c o a t . The  summer coat guard h a i r s emerge i n mass f i r s t on the  f l a n k s and then continue emerging towards neck and the p o s t e r i o r end.  The l a r g e guard h a i r s of w i n t e r coat are shed i n A p r i l  the pelage a t t h i s stage c o n s i s t s of r e s t i n g winter coat d i a t e guard h a i r s and w o o l l y under h a i r s , p l u s a c t i v e l y  and  intermegrowing  Guard h a i r s FIGURE  41.1  Deer f o l l i c l e . Notice the shape of dermal p a p i l l a and the i n n e r r o o t sheath c e l l l a y e r s and melanin d e p o s i t i o n i n c o r t e x . H. & E. FIGURE  41.2  Deer secondary f o l l i c l e . N o t i c e the e x t e r n a l r o o t sheath, c e l l o r i e n t a t i o n as w e l l as the membrane. H. & E. FIGURE 42 Guard h a i r f o l l i c l e s i n catagen. Growth has ceased and the f o l l i c l e i s withdrawing. H. & E. FIGURE  43.1  Base of f o l l i c l e i n t e l o g e n . Notice the w i t h drawn f o l l i c l e base and rounded dermal p a p i l l a and the r e s t i n g h a i r . N o t i c e p o s i t i o n of sweat gland and the r e s t i n g f o l l i c l e . H. & E. FIGURE  43.2  Close up of r e s t i n g f o l l i c l e . Notice p a r t i a l l y enclosed rounded dermal p a p i l l a .  the H. & E.  For e x p l a n a t i o n of a b b r e v i a t i o n s used please see Appendix, Page 2 1 4 .  Ill  112 summer coat guard h a i r s .  Intermediate guard h a i r s f i r s t emerge  by mid-March and l a r g e guard h a i r s by e a r l y March. all  guard h a i r f o l l i c l e s a r e v i g o r o u s l y  i n t e r m e d i a t e guard h a i r s a r e s t i l l  growing  By l a t e March  and w i n t e r coat  resting.  The f i r s t formed secondary f o l l i c l e s which g i v e r i s e t o medullated h a i r s were a l s o n o t i c e d c l e s have emergent h a i r s i n A p r i l .  growing  i n March.  These  folli-  The f o l l i c l e a t t h i s time  c o n t a i n s an emergent h a i r p l u s the o l d r e s t i n g  hairs.  By mid-May some of the s m a l l e r i n t e r m e d i a t e guard h a i r s a r e r e a c h i n g r e s t i n g stages and by l a t e June a l l h a i r s a r e i n r e s t i n g stage.  The l a r g e r guard h a i r f o l l i c l e s  coming t o r e s t l a s t .  The  f i r s t formed s e c o n d a r i e s a r e a l s o i n r e s t i n g stage now and animal is i n fully  formed summer c o a t .  By mid-July the f i r s t formed s e c o n d a r i e s s t a r t again.  growing  By the end o f J u l y a l l s e c o n d a r i e s a r e a c t i v e l y  woolly h a i r s .  growing  The p r e v i o u s year's w o o l l y h a i r s had been l o s t i n  May without any r e g e n e r a t i v e a c t i v i t y i n t h e i r f o l l i c l e s . guard h a i r f o l l i c l e s a r e a l s o  The  s t a r t i n g t o grow and by e a r l y  August the winter coat h a i r s have emerged on the s u r f a c e .  They  make t h e i r way through the growing w o o l l y h a i r s and overtake them i n growth r a t e . resting.  By October  end a l l w i n t e r coat guard h a i r s a r e  The i n t e r m e d i a t e guard h a i r s come t o r e s t and then the  l a s t guard  hairs.  The f i r s t formed secondary f o l l i c l e s a r e a l s o r e s t i n g by October.  By December a l l w o o l l y under coat h a i r s a r e r e s t i n g .  Thus l a t e r formed secondary f o l l i c l e s have a l o n g e r growing The guard h a i r f o l l i c l e s and w o o l l y under h a i r continue to r e s t t i l l growing  again.  period.  follicles  March and J u l y r e s p e c t i v e l y when they s t a r t  FIGURE 4 3 . 3 Dermal p a p i l l a i n t e l o g e n c l o s e up. L o n g i t u d i n a l s e c t i o n . H. & E . FIGURE 4 3 . 4  hair.  Close up o f s p a t u l a t e dermal p a p i l l a of guard L o n g i t u d i n a l s e c t i o n . H. & E.  FIGURE 4 3 . 5 New h a i r growing beside o l d r e s t i n g h a i r . Notice the p o s i t i o n of a r r e c t o r p i l i i muscle. L o n g i t u d i n a l s e c t i o n . H. & E.  FIGURE 4 3 . 6 Transverse s e c t i o n of 4 3 . 5 above. For e x p l a n a t i o n o f a b b r e v i a t i o n s see Appendix IV, Page 214.  H. & E. used  please  114  115 Summary Guard h a i r s of both coats of the a d u l t s have a 3 /2-month 1  growth p e r i o d .  However summer pelage i s i n a r e s t i n g s t a t e on  the body f o r two months and the winter pelage f o r f i v e months. The l a r g e guard h a i r s s t a r t growth e a r l y but come to r e s t The f i r s t formed secondaries a l s o appear t o shed h a i r s twice, and thus behave l i k e p r i m a r i e s .  last.  their  The l a t e r formed  secondaries have a 5^/2-month grossing p e r i o d and a 6^/2-month resting period.  They a r e l o s t i n May by being broken o f f a t  the surface of the s k i n .  Thus though absent from the f u n c t i o n a l  summer coat, t h e i r stubs a r e present i n the f o l l i c l e s . a r e shed i n mid-July when these f o l l i c l e s producing new h a i r a g a i n .  These  s t a r t growing and  116  TABLE 3 Annual C y c l e o f the B l a c k T a l l  Activity  Duration Prom  Summer coat grows  Deer  First  March  To Mid-June  Summer coat r e s t s  Mid-June  Mid-August  Follicle  Mid-June  Mid-July  Summer coat sheds  Mid-August  October  Winter coat grows  Mid-July  October  Winter coat r e s t s  November  April  Winter coat sheds  May  June  Woolly under coat grows  Mid-July  December  Woolly under coat r e s t s  January  Mid-July  Woolly under coat sheds  May  Mid-June  rests  FIG.44  DIAGRAMATIC REPRESENTATION  OF T H E A N N U A L HAIR C Y C L E  117  Chapter  VI  THE MORPHOMETRY OF BLACK TAIL HAIRS INTRODUCTION As shown i n Chapter IV, the deer a l t e r s i t s pelage c h a r a c t e r i s t i c s between youth and m a t u r i t y and a l s o between summer and w i n t e r , each year of i t s l i f e .  I t i s assumed t h a t the  s u c c e s s i o n of pelage and a l s o the d e t a i l s of the h a i r s  themselves  develop i n response t o g e n e t i c i n s t r u c t i o n s t h a t are e s s e n t i a l components of the e n t i r e catalogue of such t h a t govern the form and f u n c t i o n of the a n i m a l . I have d e s c r i b e d the f o l l i c l e s from which the s e v e r a l types of h a i r s a r i s e and g i v e n a g e n e r a l d e s c r i p t i o n of each type, the f e a t u r e s of the coat of which they c o n s t i t u t e a p a r t and the moult p a t t e r n s t h a t these coats f o l l o w .  I t i s important however  t o e s t a b l i s h i n more d e t a i l the d i f f e r e n c e s t h a t d i s t i n g u i s h the h a i r types and the s e a s o n a l changes they undergo amidst c o n d i t i o n s c l o s e to the optimum.  Only w i t h such d e t a i l s i n hand can a l t e r -  a t i o n s a r i s i n g from environmental impact or a l t e r a t i o n s a s s o c i a t e d w i t h s p e c i e s or geographic areas be  studied.  MATERIAL AND METHODS To e s t a b l i s h the v a r i a t i o n i n the d i f f e r e n t coat types, i n r e g i o n s w i t h i n these coat types and i n h a i r types w i t h i n these r e g i o n s , guard h a i r samples were s e l e c t e d on random b a s i s from f i v e selected regions.  These were:  118 1) Back 2) p l a n k 3) Abdomen 4 ) Thigh 5 ) Hind l e g . D i s t a l The  end.  samples were s o r t e d out i n t o l a r g e and  intermediate  guard h a i r s and were measured f o r l e n g t h and diameter.  The  ent c o l o u r e d bands present on the h a i r s were a l s o measured. data so c o l l e c t e d was  statistically  analysed  differThe  i n an I.B.M. 704-0  computer w i t h the h e l p of programmes a v a i l a b l e from the F a c u l t y of F o r e s t r y . These a n a l y s e s were of two  kinds.  A) For the study of v a r i a t i o n i n l e n g t h , diameter and zone i n d i f f e r e n t c o a t s , r e g i o n s and  type of h a i r .  B) For the study of c o r r e l a t i o n between the l e n g t h diameter i n the h a i r under d i f f e r e n t  and  circumstances.  For the f i r s t k i n d of study a nested v a r i a n c e of l e n g t h s of h a i r was  colour  done.  ( w i t h i n ) a n a l y s i s of  S i m i l a r a n a l y s i s was  taken f o r the measurements of diameter of the h a i r s .  In  under-  addition  the p r o p o r t i o n of the t o t a l l e n g t h of the h a i r under each of the f o u r c o l o u r zones was  computed and a s i m i l a r separate a n a l y s i s  of v a r i a n c e done f o r each zone.  The r e s u l t s are summarized below.  OBSERVATIONS Length The  l e n g t h measurements taken are g i v e n i n Table 5«  The r e s u l t s of a n a l y s i s of v a r i a n c e are g i v e n i n Table  4.  119  TABLE 4 Nested A n a l y s i s of Variance H a i r Length Source  Degree of freedom  Coat  Sum square  Mean square  F  3  31431.00  10477.00  318.73**  Region w i t h i n coat  16  109130.00  6820.70  207.56**  Type w i t h i n r e g i o n w i t h i n coat  20  71055.00  3552.80  108.08**  Error  660  21694.00  32.87  Total  699  233310.00  As the 'F' v a l u e s a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e range t e s t L i , (1964) was performed f o r the coat means, r e g i o n s w i t h i n coat means and type w i t h i n r e g i o n w i t h i n coat means.  The  r e s u l t s a r e t a b u l a t e d i n Table 6, where two or more means a r e underscored by the same l i n e i t denotes t h a t they a r e not s i g n i f i c a n t l y d i f f e r e n t from each other a t 5$, s i g n i f i c a n c e l e v e l . Other apparent d i f f e r e n c e s a r e s i g n i f i c a n t . To understand whether the h a i r types / r e g i o n / coat a r e or are not s i g n i f i c a n t l y d i f f e r e n t from each other i n r e s p e c t of the p a r t i c u l a r parameter under c o n s i d e r a t i o n , r e f e r t o Table 5«  The  underscoring  types  of f i g u r e s where present  i m p l i e s t h a t the h a i r  are not s i g n i f i c a n t l y d i f f e r e n t i n r e s p e c t of the parameter i n q u e s t i o n , as t e s t e d by Duncan's m u l t i p l e range t e s t . On p e r u s a l o f the data i n r e l a t i o n t o the h a i r l e n g t h the f o l l o w i n g p o i n t s emerge. The  l a r g e guard h a i r s and the intermediate  consistently d i f f e r e n t i n length.  guard h a i r s are  Only i n r e g i o n f i v e of the  BIRTH  FAWN3  WINTER  ADULT SUMMER  ADULT WINTER  COAT T Y P E S FIG. 4 5  GUARD HAIR LENGTH RELATIONSHIP IN DIFFERENT COATS O F B L A C K TAIL D E E R ; WITH T H E I R MAJOR HAIR COLOUR Z O N E S  H o  TABLE 5 Lengths of H a i r Samples i n mm H a i r type 1 (Large guard) No. of Coat type Coat I ( B i r t h coat)  Coat I I Fawn w i n t e r coat  Region  1 2 3 4 5  1 2 3 4 5  Length  (mm)  46.1875 58.2308 44.0000 41.9333 15.8000  56.0000 59.0000 51.6364 55.8750 13.7143  Observation  16 13 11 15 10  11 6 11 16 14  H a i r type 2 (Intermediate guard) No. of Length i n mm 1  21.8696 30.8824 18.7200 23.8400 11.9545  39.2000 37.0000 32.0417 34.9630 II.3125  Observation  23 17 25 25 22  31.8462(39) 42.7333(30) 26.4444(36) 30.6250(40) 13.1563(32)  Average  28.9379(177) 44.3333(36) 41.5313(32) 38.2000(35) 42.7442(43) 12.4333(30)  25 26 24 27 16 Average  Coat I I I Adult summer coat -  ...  1 2 3 4 5  76.6923 79.0769 70.1429 73.0000 23.3077  13 13 14 13 13  43.0000 46.9583 38.7600 47.0000 12.7917  Coat IV Adult w i n t e r coat  25 24 25 25 24 Average  •  1 2 3 4 5  58.1818 58.3333 49.5556 58.1111 21.3750  11 12 9 9 8  43.2083 44.8400 43.3636 39.4400 11.8333  Mean l e n g t h & No. of Observations  24 25 11 25 24  Average  36.7784(176) 54.5263(38) 58.2432(37) 50.0256(39) 55.5947(38) 16.4865(37) 47.1536(189) 47.9143(35) 49.2162(37) 46.1500(20) 44.3824(34) 14.2188(32) 40.4114(158)  122  TABLE 6 Duncan's M u l t i p l e Range Test  H a i r Length i n m i l l i m e t e r s A W i t h i n coats Coat Mean l e n g t h  III  47.15  IV  40.41  II  36.78  I  28.94  B Regions w i t h i n c o a t s Coat I Region Mean l e n g t h  2  1  42.73  4  3  5  30.63  26.44  13.16  2  3  5  38.20  12.43  Coat I I Region Mean l e n g t h  1  4  44.33  42.74 Coat I I I  Region Mean l e n g t h  2  4  1  3  5  58.24  55.89  54.52  50.03  16.49  Coat IV Region Mean l e n g t h  2  1  3  4  5  49.22  47.91  46.15  44.30  12.22  C - The h a i r types w i t h i n r e g i o n s see Table 5  123 fawn b i r t h coat and fawn w i n t e r  coat a r e these d i f f e r e n c e s  s t a t i s t i c a l l y not s i g n i f i c a n t .  The h a i r s i n r e g i o n f i v e o f a l l  the coats were c o n s i d e r a b l y s m a l l e r i n l e n g t h than those other r e g i o n s  i n the  sampled.  Amongst the r e g i o n s sampled f o r l e n g t h , the h a i r s on f l a n k s ( r e g i o n two) were observed t o be the l o n g e s t .  The i n c r e a s e s i n  h a i r l e n g t h can be a t t r i b u t e d e i t h e r t o f a s t e r r a t e of growth or to l o n g e r d u r a t i o n o f growth or both.  No o b s e r v a t i o n s  i n this  r e s p e c t a r e a v a i l a b l e i n r e l a t i o n t o the d i f f e r e n t body r e g i o n s of the b l a c k t a i l deer.  I t may be of i n t e r e s t t o i n v e s t i g a t e h a i r  growth over d i f f e r e n t body r e g i o n s o f the same animal over a p e r i o d of time and e s t a b l i s h presence of growth g r a d i e n t s i f any. The h a i r l e n g t h a l s o i n c r e a s e s from fawn b i r t h coat onward to a d u l t summer coat but decreases a g a i n i n the a d u l t w i n t e r  coat.  Diameter The diameter measurements taken a r e shown i n Table  8 and  the r e s u l t s of the a n a l y s i s of v a r i a n c e a r e g i v e n i n Table 7«  TABLE 7 Nested A n a l y s i s o f V a r i a n c e H a i r Diameter Source  Degree of freedom  Sum square  Mean square  3  1977300.OO  659100.00  819.88**  Region w i t h i n coat  16  1065400.00  66587.OO  82.83**  Type w i t h i n r e g i o n w i t h i n coat  20  358400.00  17920.00  22.29**  Error  660  530570.00  803.90  Total  699  393700.00  Coat  1 2 4  As the 'F' v a l u e s a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e range t e s t L l  was performed f o r the coat means, r e g i o n s  ( 1 9 6 4 )  w i t h i n coat means, and the h a i r type w i t h i n r e g i o n w i t h i n coat means.  The r e s u l t s a r e t a b u l a t e d i n Table 9 .  means a r e underscored  Where two or more  by the same l i n e i t denotes t h a t they a r e  not s i g n i f i c a n t l y d i f f e r e n t from each other a t $% s i g n i f i c a n c e level. To understand  whether h a i r types / r e g i o n / coat are or are  not s i g n i f i c a n t l y d i f f e r e n t from each other i n r e s p e c t t o diameter r e f e r to Table 8 .  F i g u r e s underscored  i n d i c a t e t h a t the h a i r  type i n q u e s t i o n a r e not s i g n i f i c a n t l y d i f f e r e n t i n r e s p e c t of t h i s parameter  (diameter), as t e s t e d w i t h Duncan's m u l t i p l e range  test. I n r e s p e c t t o h a i r diameters the fawn b i r t h coat the diameters  the f o l l o w i n g can be s a i d .  In  of l a r g e guard h a i r s and i n t e r -  mediate guard h a i r s a r e not s i g n i f i c a n t l y d i f f e r e n t but i n subsequent c o a t s g e n e r a l l y the l a r g e guard h a i r s , though of g r e a t e r l e n g t h , possess guard h a i r s .  s m a l l e r diameters  than the comparable  intermediate  The c o n s i s t e n t exceptions t o t h i s have been i n  r e g i o n f i v e of a l l the f o u r c o a t s and a l s o r e g i o n s one and two of three and r e g i o n one of coat f o u r . In the fawn b i r t h coat and fawn winter coat the g r e a t e r diameter i s a t t a i n e d by h a i r s i n the f l a n k r e g i o n .  /  But i n the  a d u l t summer and w i n t e r coats i t was the abdominal h a i r s which c h a r a c t e r i s t i c a l l y a t t a i n e d the l a r g e s t The  average diameter f o r the pelage  from fawn b i r t h coat onwards t i l l reached. hairs.  diameters. continues t o i n c r e a s e  the a d u l t winter coat stage i s  Thus w i n t e r h a i r s a r e o f l a r g e r diameter than the summer  BIRTH  FAWN WINTER  ADULT WINTER  ADULT SUMMER COAT TYPES  FIG.46  G U A R D HAIR  DIAMETER  RELATIONSHIP  IN D I F F E R E N T B L A C K T A I L C O A T S  TABLE 8 Diameter of H a i r Samples i n Microns Type 2 Type 1  Coat type Coat I B i r t h coat  Body Region  1 2 3 4 5  Diameter 60.3750  62.9231 50.8182 73.1333 65.9000  No. of Observations 1 6 1 3  11  1 5  10  Diameter  57.3478 72.8824 56.4400 75.7200 62.9545  No. of Observations 2 3  58.5897(39)  1 7  68.5667(30)  2 5 2 5  22 Average  Coat I I Fawn w i n t e r coat  1 2 3 4 5  99.6364 108.0000 117.3636 116.3125 84.3^1  11 6 11 1 6  14  152.6400 177.6538 142.1250 156.0741 85.8125  2 5  26 24 27 1 6  Average Coat I I I A d u l t summer coat  , 1 2 3 4 5  150.3077 174.2308  1 3 1 3  153.4286  14  1 5 5 . 3 0 7 7  1 3  9 9 . 0 7 6 9  1 3  143.8400 170.1667 227.8800  187.8800 113.0000  2 5  24 2 5 2 5  24 Average  Coat IV Adult winter coat  1 2 3 4 5  200.4545 194.8333 2 3 8 . 6 6 6 7  I63.OOOO 76.0000  11 12 9 9 8  213.4167 261.4400 387.0909  273.2800 96.3750  Mean Diameter  24  54.7220(36) 74.7500(40) 63.8750(32)  64.1017(177) 136.4444(36)  164.2188(32)  134.3429(35) 141.2791(43) 85.1333(30)  133.511^(176)  146.0526(38)  171.5946(37)  201.1538(39) 176.7368(38) 108.1081(37) 161.1640(189)  209.3429(35)  11  239.8378(37) 320.3000(20)  24  91.2813(32)  2 5  2 5  Average  244.0882(34)  214.0949(158)  127  TABLE 9 Duncan's M u l t i p l e Range Test H a i r Diameter i n microns A Within Coat Mean diameter  IV  214^09  coats  III  161.16  II  I  133.Si  64.10  B Regions w i t h i n coats Coat I Region Mean diameter  4  2  5  1  3  74.75  68.56  63.57  58.58  54.72  1  3  5  Coat I I Region Mean diameter  2 164.21  4 141.27  136.44  134.34  85.13  Coat I I I Region Mean diameter  3 201.15  4 176.73  2 171.59  1 146.05  5 108.10  Coat IV Region Mean diameter  3 320.30  4 244.08  2 239.83  1 209.34  5 91.28  C H a i r type w i t h i n r e g i o n r e f e r to Table 8  128 Colouration The  c o l o u r a t i o n of the coats d i f f e r g r e a t l y , p a r t i c u l a r l y  between the summer and winter pelages.  The summer coats a r e  r e d d i s h - y e l l o w w h i l e the winter coats a r e g r e y i s h .  The fawn  b i r t h coat and a d u l t summer coat have s i m i l a r g e n e r a l c o l o u r a t i o n of h a i r s but s u b t l e d i f f e r e n c e s do e x i s t .  The yellow  coloured  zone which f o l l o w s the b l a c k t i p i s s h o r t , but present i n the a d u l t summer coat w h i l e i t i s t o t a l l y absent i n the fawn b i r t h coat.  The presence o f white spots on the fawn b i r t h coat i s a l s o  very c h a r a c t e r i s t i c .  The fawn winter coat i s a l s o a l i t t l e  darker  than the a d u l t w i n t e r coat, as some of the guard h a i r s i n i t a r e completely  b l a c k , p a r t i c u l a r l y on the back and s i d e s .  The d i f f e r -  ent c o l o u r bands on an a g o u t i p a t t e r n h a i r r e p r e s e n t p u l s e s o f a c t i v i t y i n pigment p r o d u c t i o n by the f o l l i c l e . study of h a i r s present i n the d i f f e r e n t pelages  Superficial of t h i s deer l e d  us t o the impression t h a t these p u l s e s , and the r e s u l t s as seen i n the pigmentation  of the h a i r , d i f f e r e d w i t h i n the d i f f e r e n t  pelages, as w e l l as between body r e g i o n s .  To explore t h i s i n  more d e t a i l a p p r o p r i a t e samples o f h a i r were s u b j e c t e d to d e t a i l e d measurement of the l e n g t h s of each o f f o u r c o l o u r segments, b l a c k , y e l l o w , grey  (or r e d d i s h - y e l l o w ) , and white  (colourless).  B l a c k c o l o u r e d zone In the r e g i o n s sampled the t i p of the h a i r i s b l a c k . i s a l s o t r u e f o r abdominal h a i r s .  This  T h i s zone was l o n g e r i n the  back r e g i o n of the fawn b i r t h coat but a t t a i n e d i t s maximum extent i n some h a i r s o f the back i n fawn winter c o a t . the l a r g e guard h a i r s have g r e a t e r p r o p o r t i o n of t h i s  Generally black  100  A  BIRTH  FAWN  ADULT  WINTER  SUMMER  COAT  ADULT WINTER.  TYPES  FIG.47 P E R C E N T A G E S OF D I F F E R E N T COLOURED ZONES IN COAT TYPES IN RELATION TO TOTAL HAIR LENGTH , A = B L A C K , B = Y E L L O W , C= REDDISH Y E L L O W , D= GREY , E = W H I T E  H  £  TABLE 10 Black Coloured Zone H a i r type I Coat type Coat I  Region 1 2 3 4  5  Black c o l o u r zone 0.3993 0.1385 0.2307 0.1711 0.0941  H a i r type I I  No. of Observations 16 13 11  15 10  Black colour zone 0.2167 0.1260 0.04-50 0.1044 0.0874  No. of Observations  23  17  25 25 22  Average Coat I I  1 2 3 4  5  0.6751 0.1182 0.03840.1286 0.0828  11 6 11 16  14  0.1258 0.0964 0.0721 0.0812 0.0889  25  26 24  27 16  Average Coat I I I  1 2 3 4 5  0.1522 0.0924  0.0575  0.1114 0.0732  13 13  0.1269 0.07?8  13  0.1021 0.1037  14  13  O.O878  25 24  25 25 24  Average Coat IV  1 2 3 4  5  0.0303  0.1432  0.1633  0.1538 0.0853  11 12 9 9 8  0.0969 O.O656 0.0604 0.0706 0.0851  24  25  11  25  24  Average  Mean & No.of Observations 0.2916(39) 0.1314(30) 0.1017(36) 0.1294(40) 0.0895(32) 0.1526(177) 0.2936(36) 0.1005(32) 0.0615(35) 0.0989(43) 0.0861(30) 0.1294(176) 0.1355(38) 0.0843(37) 0.0770(39) 0.1053(38) 0.0930(37) 0.0990(189) 0.1074(35) 0.0908(37) 0.1067(20) 0.0926(34) 0.0851(32) 0.0957(158)  131 c o l o u r e d zone, than the i n t e r m e d i a t e d e p i c t s the extent  guard h a i r t y p e s .  Table 10  o f t h i s r e g i o n amongst the samples s t u d i e d  and a l s o i d e n t i f i e s those not s i g n i f i c a n t l y d i f f e r e n t from each other  (underlined f i g u r e s ) .  Taking  the average f o r the coats, i t  i s found t h a t v t h e b l a c k c o l o u r e d r e g i o n has maximum extent (15% of t o t a l h a i r l e n g t h ) tently t i l l  i n fawn b i r t h coat and decreases c o n s i s -  i t a t t a i n s a l e v e l o f 9% i n a d u l t winter  coat.  TABLE 11 Nested A n a l y s i s of V a r i a n c e . Degree of freedom  Source  3  Coat  Black Coloured  Region  Sum square  Mean square  0.38033  0.12678  66.38**  P  coat  16  2.3570  0.14731  77.13**  Type w i t h i n r e g i o n w i t h i n coat Error  20  3.1390  0.15695  82.18**  660  1.2605  699  7.1368  Region w i t h i n  Total  .0019098  As the 'F* values a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e range t e s t was performed f o r the coat means, r e g i o n w i t h i n means and type w i t h i n r e g i o n w i t h i n coat means. t a b u l a t e d i n Table 1 2 .  coat  The r e s u l t s a r e  Where two or more means a r e underscored  by the same l i n e i t denotes t h a t they a r e not s i g n i f i c a n t l y d i f f e r e n t from each other a t 5% s i g n i f i c a n c e l e v e l .  132  Table  12  Duncan's M u l t i p l e Range Test B l a c k c o l o u r e d r e g i o n ( r a t i o of h a i r A Within Coat Black colouration  I  coats  II  III  .1294  .1526  lengths)  0.0990  IV  0.0957  B Regions w i t h i n coats Coat I Region Black colouration  1 0.291600  2  4  0.131400  Q.129400  3  5  0.101700 O.895OO  Coat I I Region Black colouration  1  2  0.293600  0.100500  4  0.098900  5  3  0.086100 0.061500  Coat I I I Region Black colouration  1  4  0.135500  0.105300  5  0.093000  2  3  0.084300 0.077000  Coat IV Region Black colouration  1 0.107400  3  4  0.106700  0.092600  2  5  0.908000 0.085100  C - H a i r types w i t h i n r e g i o n s r e f e r to Table  10  133  Yellow c o l o u r e d zone In a l l w i n t e r coats and t o a s m a l l extent i n the i n t e r mediate guard h a i r s from back of a d u l t summer c o a t , a zone of yellow c o l o u r a t i o n l i e s below the b l a c k t i p . completely m i s s i n g i n the fawn b i r t h c o a t . maximum extent i n a d u l t w i n t e r c o a t .  T h i s zone i s  I t reaches i t s  R e g i o n a l l y i t reaches i t s  g r e a t e s t extent i n r e g i o n f i v e of the fawn w i n t e r c o a t . Table 1 4 . TABLE 13 Nested A n a l y s i s of V a r i a n c e . Yellow Coloured Zone Sum square  Degree of freedom  Source  Mean square  P  3  2.8983  O.966II  710.10**  Region w i t h i n coat  16  4.9296  0.30810  226.46**  Type w i t h i n r e g i o n w i t h i n coat Error  20  1.5374  O.O76869  660  0.89794  0.013605  Total  669  Coat  56.50**  10.263  As the 'F' v a l u e s a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e range t e s t L l ( 1 9 6 4 )  was performed f o r the coat means, r e g i o n  w i t h i n coat means and type w i t h i n r e g i o n w i t h i n coat means. r e s u l t s a r e t a b u l a t e d i n Table 1 4 . underscored  The  Where two or more means a r e  by the same l i n e i t denotes t h a t they a r e not s i g n i f  i c a n t l y d i f f e r e n t , from each other a t $% l e v e l o f s i g n i f i c a n c e . To understand  i f any of the h a i r type / r e g i o n / coat a r e not  s i g n i f i c a n t l y d i f f e r e n t i n r e s p e c t of the parameter i n q u e s t i o n (yellow c o l o u r a t i o n ) see Table 1 4 .  I f underscored  the f i g u r e s  are n o t s i g n i f i c a n t l y d i f f e r e n t as per Duncan's m u l t i p l e range t e s t a t 5% s i g n i f i c a n c e  level.  TABLE 14 Yellow c o l o u r e d Zone Extent H a i r Type I Coat type Coat I  H a i r Type I I  Region  Yellow c o l o u r e d Zone  No.of Observations  1 2 3 4 5  0.0000 0.0000 0.0000 0.0000 0.0000  11 13 11 15 10  Yellow c o l o u r e d Zone  0.0000 0.0000  O.OOOO  0.0000 0.0000  No.of Observations  Mean & No.of Observations  23  0.0000(39) 0.0000(30) 0.0000(36) 0.0000(40) 0.0000(32)  17  25 25 22 Average  Coat I I  1 2 3 4 5  0.0212 0.0000  0.0197  0.0000  0.4542  11 6 11 16 14  0.0556 0.0961 0.0000 0.0378 0.4348  25 26 24  27 16  Average Coat I I I  Coat IV  1 2 3 4 5  0.0000 0.0000 0.0000 0.0000 0.0000  13 13  1 2 3 4 5  0.3126 0.3761 0.0000  11 12 9 9 8  0.2440 0.1080  14  13 13  0.0357 0.0000 0.0000 0.0000 0.0000 0.1052 0.0588 0.0000 0.0934 0.2727  25 24  25 25 25  Average 24  25 11 25 24  Average  0.0000(177) 0.0451(36) 0.0781(32) 0.0062(35) 0.0238(43) 0.4438(30) 0.1061(176) 0.0235(38) 0.0000(37) 0.0000(39) 0.0000(38) 0.0000(37)  0.0047(189)  0.1702(35) 0.1617(37) 0.0000(26) 0.1333(34) 0.2315(32) 0.1511(158)  135  TABLE 15 Duncan s M u l t i p l e Range Test 1  Yellow c o l o u r e d A Within Coat  I  Yellow zone  0.000000  zone  coats  III  II  IV  0.004700  0.106100  0.151100  B Regions w i t h i n  coats  .Coat I A l l f i g u r e s a r e zero no s i g n i f i c a n t d i f f e r e n c e Coat I I  3  Region Yellow zone  coloured  0.028300  1 0.045100  2  5  0.078100  0.443800  Coat I I I  2  Region Yellow zone  0.006200  4  coloured  0.000000  3 0.000000  4 0.000000  5 0.000000  1 0.023500  Coat IV  3  Region Yellow zone  coloured  0.000000  4 0.133300  2 0.161700  C H a i r types w i t h i n r e g i o n s  1 0.170200  see Table 14  5 0.231500  136 Grey or r e d d i s h - y e l l o w c o l o u r e d zone T h i s i s the next c o l o u r zone on the h a i r s h a f t .  In winter  coat i t i s grey and i n summer coat i t i s r e d d i s h - y e l l o w .  It i s  c h a r a c t e r i s t i c a l l y o f g r e a t e r extent i n the abdominal r e g i o n . T h i s zone i s l a r g e r i n the fawn b i r t h  coats and a d u l t summer  coats than i n the other p e l a g e s . The q u a n t i t a t i v e d e t a i l s o f t h i s r e g i o n a r e g i v e n i n  Table  1?. TABLE 16 Nested A n a l y s i s of Variance  of Grey/.;Reddlsh-Yellow Zone Sum square  Mean square  3  2.6347  0.87825  104.57**  Region w i t h i n coat  16  7.6320  0.47700  56.79**  Type w i t h i n r e g i o n w i t h i n coat Error  20  4.9701  0.24851  29.59**  660  5.5431  0.0083986  Total  699  2.0780  Degree of freedom  Source Coat  F  As the F ' v a l u e s a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e !  range t e s t L i (1964) was performed f o r the coat means, r e g i o n w i t h i n coat means, and type w i t h i n r e g i o n w i t h i n coat means. r e s u l t s a r e t a b u l a t e d i n Table 1 8 .  Where f i g u r e s have been under-  scored by a l i n e i t means t h a t they a r e not s i g n i f i c a n t l y a t $% l e v e l o f s i g n i f i c a n c e .  The  different  To f i n d out i f h a i r types w i t h i n  r e g i o n w i t h i n coat a r e s i g n i f i c a n t l y not d i f f e r e n t i n r e s p e c t o f parameter i n q u e s t i o n underscored  ( g r e y / r e d d i s h - y e l l o w zone) see Table 17  f i g u r e s imply t h a t they a r e not s i g n i f i c a n t l y  different.  TABLE 17 Grey or Reddish-yellow Zone  Extent  <  H a i r Type 2  H a i r Type 1  Coat type Coat  Region  1 2 3 4 5  Grey c o l o u r e d zone or Reddish-yellow  0.5787 0.8442 0.7453 0.8043 0.S365  •No.of Observations  16 13 11 1 5  10  Grey c o l o u r e d zone or Reddish-yellow  0.7477 0.8484 0.9720 0.8537 0.8206  'No.of Observations 2 3  17 2 5 2 5  22 Average  Coat I I  l  2 3 4 5  0.2874 0.8390 0.9223 0.8572 0.3893  11 6 11 16 14  O.7815 0.7726 0.895? 0.8551 0.3879  | 2 6 2  24 2 7  16 Average  Coat I I I  l  2 3 4 5 Coat IV  1 2 3 4 5  0.8347 0.89^9 0.9278 0.8747 0.8803  1 3 1 3  14 1 3  13  0.8123 0.8986 0.8717 0.8760 0.8168  2 5  24 2 5 2 5  24 Average  O.5368 0.4362 0.8002  0.5675  0.7578  11 12 9 9 8  0.7742 0.8528 0.8849 0.8204 0.5707  24 2 5  11 2 5  24 Average  Mean & No.of Observations  0.6184(39)  0.8466(30) 0.9027(36)  0.8352(40)  0.8256(32)  0.8146(177) 0.6305(36)  0.1850(32)  0.9042(35) 0.8559(43)  0.3885(30)  0.7269(176) 0.8200(38) 0.8973(37) 0.8918(39) 6.8756(38) 0.8391(37) 0.8649(189) 0.6996(35) 0.7265(37) 0.8468(20) 0.7534(34) 0.6175(32) 0.7125(158)  138  TABLE 18 Duncan's M u l t i p l e Range Test Grey/Reddish-yellow Zone A W i t h i n coats IV  II  I  III  0.719500  0.726900  0.814600  0.846900  Coat Grey/reddish yellow zone  B  Region w i t h i n coats Coat I  Region Grey/reddish yellow zone  1 0.678400  5  4  0.825600  6.835200  2  .  3  0.846600 0.902700  Coat I I Region Grey/reddish yellow zone  5 O.388500  1  2  0.630500  0.785000  4  3  0.855900 0.904200  Coat I I I Region Grey/reddish yellow zone  1  5  4  0.820000  0.839100  0.875600  3  2  0.891800 0.897300  Coat IV Region Grey/reddish yellow zone  5 0.617500  1 0.699600  2 0.726500  4  3  0.753400 0.846800  C H a i r types w i t h i n r e g i o n see Table 17  139 White c o l o u r e d zone  (Translucent)  T h i s zone c o n s t i t u t e s the b a s a l s t a l k o f the h a i r .  The  medulla i s m i s s i n g i n t h i s r e g i o n and the c u t i c l e and c o r t e x a r e translucent. T h i s r e g i o n i s c h a r a c t e r i s t i c a l l y longer i n the abdominal hairs.  C o n s i d e r i n g the coats i t reaches  i n the fawn b i r t h c o a t .  i t s g r e a t e r development  The s i g n i f i c a n c e of i t ' s r e a c h i n g  g r e a t e r extent i n abdominal h a i r s i s not c l e a r .  It i s likely  t h a t medulla f o r m a t i o n stops e a r l y i n t h i s a r e a and consequently a g r e a t e r p r o p o r t i o n of non medullated The  b a s a l r e g i o n i s formed.  e x p l a n a t i o n of e a r l y stoppage o f medulla f o r m a t i o n here i s  l o c k e d i n the complex b i o c h e m i c a l a c t i v i t y t a k i n g p l a c e w i t h i n the h a i r f o l l i c l e s and needs f u r t h e r study. Where two of more means a r e underscored  i t denotes t h a t f o r  the parameter i n q u e s t i o n they a r e not s i g n i f i c a n t l y from each other a t  level.  different  To f i n d out i f any o f the types  w i t h i n r e g i o n s w i t h i n coats a r e not s i g n i f i c a n t l y d i f f e r e n t to Table 19.  refer  F i g u r e s u n d e r l i n e d here a r e t e s t e d by Duncan's  m u l t i p l e range t e s t and found  t o be not s i g n i f i c a n t l y  different.  TABLE 19 White Coloured Zone H a i r Type I Coat  type  Coat I  Region 1 2 3 4  5  Coat I I  1 2 3 4 5  White c o l o u r e d zone 0.0220 0.0173 0.0240 0.0246 0.0753  H a i r Type I I  No. o f White c o l o u r e d zone Observations  16 13 11  15  10  0.0467 0.0328  0.0550  0.0444 0.0920  No. o f Observations  23  17  25 25 22  Average 0.0181 0.0171 0.0197 0.0214 0.0753  11 6 11  16 14  0.0261 0.0276 0.0319 0.0219 0.0920  25 26 24  27 16  Average Coat I I I  1 2 3 4 5  0.0131 0.0127 0.0147 0.0138  0.0465  13  13  14 13 13  0.0236 0.0216 0.0522  25  O.0795  24  0.0219  24  25 25 Average  Coat IV  1 2 3 4 5  0.0173 0.0174 0.0405 0.0173 0.0490  11 12 9 9 8  0.0238 0.0228 0.0473 0.0259 0.0851  24 25 11 25 24 Average  Mean & No.of Observations  .0366(34) .0261(30) .0455(36) .0370(40) .0808(32)  .0458(177) .0236(36) .0256(32)  .0281(35) .0262(43) .0818(30)  .035^(176  0.0200(38) 0.0185(37) 0.0387(39) 0.0191(38) 0.0679(37)  0.0328(189) 0.0217(35) 0.0211(37) 0.0442(26) 6.0236(34) 0.0761(32) 0.0358(158)  l 4 l  TABLE 2 0 Nested A n a l y s i s of V a r i a n c e . White Coloured Degree of freedom  Source Coat coat  Type w i t h i n r e g i o n w i t h i n coat Error Total  Mean square  F  0 . 0 1 7 5 8 0  . 0 0 5 8 5 9 9  1 6  0 . 2 9 1 2 1  .018201  2 5 0 . 7 6 * *  2 0  0 . 0 5 7 9 6 2  .002898  3 9 . 9 3 * *  6 6 0  0 . 0 4 7 9 0 3  . 0 0 0 0 7 2 5 8 1  699  0.41466  3  Region w i t h i n  Sum square  Zone  8 0 . 7 4 * *  As the ' F ' v a l u e s a r e h i g h l y s i g n i f i c a n t Duncan's m u l t i p l e range t e s t L i  ( 1 9 6 4 )  was performed f o r the coat means, r e g i o n s  w i t h i n coat means and type w i t h i n r e g i o n w i t h i n coat means. results  a r e t a b u l a t e d i n Table 2 1 .  The  142  TABLE 21 Duncan's M u l t i p l e Range Test White c o l o u r e d zone .A W i t h i n III  II  IV  0.032800  0.035400  0.035800  Coat White c o l o u r e d zone  coats I  0.045800  B Regions w i t h i n coats Coat I Region White c o l o u r e d zone  ?  p.026100  1  3  4  0.036600  0.037000  0.045500  5 0.086800  Coat I I Region White c o l o u r e d zone  1 0.023600  2  3  4  ;  0.025600  0.026200  0.028100  5 0.081000  Coat I I I Region White c o l o u r e d zone  2 0.018500  1  4  0.019100  0.020000  3  5  0.035700  0.067900  Coat IV Region White c o l o u r e d zone  2 0.021100  1  0.021700  3  4  0.023600  0.044200  C h a i r types w i t h i n r e g i o n see Table 19  5 0.076100  Summary T h i s chapter d e a l s w i t h morphometric o b s e r v a t i o n s on h a i r s i n r e s p e c t o f t h e i r l e n g t h , diameter and c o l o u r a t i o n ( i . e . prop o r t i o n o f the t o t a l h a i r l e n g t h occupied by each of the c o l o u r zones).  The data a r e based on o b s e r v a t i o n s on random samples o f  two h a i r types  ( l a r g e guard h a i r and i n t e r m e d i a t e guard h a i r ) .  These h a i r s were s t u d i e d i n the f o u r coats t r e a t e d as a whole).  being  Comparative v a r i a t i o n was a l s o s t u d i e d i n  r e s p e c t o f f i v e standard coats.  ( i . e . each coat  s e l e c t e d r e g i o n s w i t h i n each o f the  F i n a l l y , the h a i r types w i t h i n each r e g i o n were i n v e s t i -  gated and compared. Nested  ( w i t h i n ) a n a l y s i s of v a r i a n c e was done on d a t a  obtained on h a i r l e n g t h , h a i r diameter, zones p r e s e n t on the h a i r s h a f t .  and the d i f f e r e n t c o l o u r  The _'F' v a l u e s obtained were  h i g h l y s i g n i f i c a n t , i n d i c a t i n g t h a t there was s t a t i s t i c a l l y s i g n i f i c a n t v a r i a t i o n between some o f the aspects compared.  To  f i n d out the s t a t i s t i c a l s i g n i f i c e n c e of the i n d i v i d u a l v a l u e s , Duncan's m u l t i p l e range t e s t was a l s o done. The  l a r g e guard h a i r s and the i n t e r m e d i a t e guard h a i r s a r e  consistently different i n length.  Only i n r e g i o n f i v e of the  fawn b i r t h coat and fawn winter coat a r e these d i f f e r e n c e s not significant.  The h a i r s i n r e g i o n f i v e of a l l the coats were  c o n s i d e r a b l y s h o r t e r than those  i n the other r e g i o n s  Amongst r e g i o n s sampled h a i r s were found flanks.  sampled.  t o be l o n g e s t on the  The h a i r l e n g t h i n c r e a s e s from fawn b i r t h coat onward t o  a d u l t summer coat but decreases  i n the a d u l t w i n t e r  In fawn b i r t h coat the diameters  coat.  o f l a r g e guard h a i r s and  i n t e r m e d i a t e guard h a i r s a r e not s i g n i f i c a n t l y d i f f e r e n t , but  100  80  60 LU  o  B  CC LU  °- 4 0  20  o BIRTH  FAWN WINTER  ADULT SUMMER COAT  ADULT WINTER  TYPES  FIG.48 PERCENTAGES OF DIFFERENT COLOURED ZONES IN VISIBLE PORTION OF P E L A G E HAIR (ASSUMED TO BE 10 MM IN WINTER COAT AND 2 0 M M IN S U M M E R COAT) A = B L A C K ,B = Y E L L O W , C =GREY , D= REDDISH YELLOW  145  LENGTH EXPOSED TO INCIDENT LIGHT  S U M M E R COAT (LONG)  WINTER COAT (SHORT)  FIG, 49 DIAGRAM R E R R E i l N T I N O POSITION OF OF GUARD HAIRS IN S U M M E R COAT AND WINTER COAT  146 subsequently  l a r g e guard h a i r s , though of g r e a t e r l e n g t h ,  s m a l l e r diameters  than comparable Intermediate  possess  guard h a i r s .  The  average diameter f o r the pelage continues t o i n c r e a s e from fawn b i r t h coat onwards u n t i l a d u l t winter coat stage i s reached. The w i n t e r h a i r s a r e of l a r g e r diameter than the summer h a i r s . In fawn b i r t h coat and fawn w i n t e r coat the g r e a t e r diamet e r was n o t i c e d t o be a t t a i n e d by h a i r s i n f l a n k r e g i o n .  In  a d u l t summer and w i n t e r c o a t s i t was the abdominal h a i r s which attained greater  diameter.  The b l a c k c o l o u r e d zone has maximum extent i n the fawn b i r t h coat and decreases The  consistently t i l l  i t reaches  adult winter  coat.  l a r g e guard h a i r s have g r e a t e r p r o p o r t i o n o f t h i s than the  i n t e r m e d i a t e guard h a i r s . The coat.  Even abdominal h a i r s have dark t i p s .  yellow c o l o u r e d zone i s completely m i s s i n g i n fawn b i r t h  I t i s present t o a v e r y s m a l l extent i n the l o n g e r h a i r s  of the a d u l t summer c o a t . coat, but reaches  I t i s w e l l developed  i n fawn winter  i t s maximum extent i n the a d u l t w i n t e r  coat.  The g r e y - r e d d i s h yellow zone c o n s t i t u t e s the b u l k of the s h a f t — except  i n d i s t a l e x t r e m i t i e s of l i m b s .  yellow i n summer and grey i n w i n t e r c o a t s .  I t i s reddish  I t reaches i t s  g r e a t e s t p r o p o r t i o n i n abdominal h a i r s where i t i s always p a l e grey i n c o l o u r . A white c o l o u r e d  ( t r a n s l u c e n t ) zone c o n s t i t u t i n g the b a s a l  s t a l k of the h a i r s i s c h a r a c t e r i s t i c a l l y longer i n abdominal h a i r s . I t c o n s i s t s only o f c o r t e x and h a i r c u t i c l e . absent  here.  Pigmentation  The medulla being  of any k i n d i s l a c k i n g i n t h i s zone.  14-7  oI 0  i  i  10  i  i  20  i  i  30  i  i  40  i  i  50  i  i  60  L E N G T H , MM FIG. 5 0 R E G R E S S I O N LINES COMPARING L E N G T H AND D I A M E T E R R E L A T I O N S H I P IN FAWN S P O T T E D A R E A A G A I N S T F A W N N O N - S P O T T E D A R E A AND ALSO IN A D U L T WINTER C O A T  70 FIG. 51 HAIR L E N G T H AND D I A M E T E R R E L A T I O N S H I P IN F A W N BIRTH COAT IN A R E A S OTHER T H A N WHITE S P O T S ( S C A T T E R G R A M ) 60  50  I  40  X Iw 30 20  I  10  0  10  20  30  40  50  DIAMETER,  60 MICRONS  70  80  90  100 CD  70|  FIG. 52 HAIR L E N G T H A N D D I A M E T E R R E L A T I O N S H I P IN FAWN BIRTH C O A T WHITE S P O T T E D REGION ( S C A T T E R G R A M )  60  50  40 x Iz LL)  30  20h  _i  10  20  30  i _  40  50  60  D I A M E T E R , MICRONS  70  80  90  100 t—  1  VO  70, FIG. 53 HAIR L E N G T H AND D I A M E T E R  RELATIONSHIP  IN A D U L T (BACK) W I N T E R C O A T ( S C A T T E R G R A M ) 60  50  40  30  20  10 60  80  100  120  140  160  180  D I A M E T E R .MICRONS  200  220  240  260  H o  80 FIG. 5 4 HAIR L E N G T H AND DIAMETER RELATIONSHIP IN A D U L T ( B A C K ) S U M M E R COAT ( S C A T T E R G R A M )  70  60  50  z  UJ  40  30  20  10 I 60  '  1  80  "  1  100  1  1—  120  1  140  I  I  160  I  I  180  D I A M E T E R , MICRONS  I  I  200  •  •  220  I  I  240  L  26  152 Chapter  VII  EFFECT OF ADVERSE NUTRITION AND  VARIATION  OF HABITAT ON CERVID PELAGE INTRODUCTION B l a c k t a i l deer are o f t e n s h o r t of food i n w i n t e r , and where p o p u l a t i o n s are h i g h many animals d i e .  The adverse  nutri-  t i o n a f f e c t s the g e n e r a l b i o l o g y of the animal i s a t r u i s m . However there i s no i n f o r m a t i o n upon the i n f l u e n c e of impaired n u t r i t i o n upon the p i l a r y system and whether or not any  imposed  changes i n the pelage may  c o n t r i b u t e t o the w i n t e r m o r t a l i t y of  deer l i v i n g under adverse  circumstances.  The e f f e c t of n u t r i t i o n on animal pelage has a t t r a c t e d some attention.  F l e s c h (195*0 touches on t h i s .  Ryder (1958)  has  adequately reviewed the n u t r i t i o n a l f a c t o r s a f f e c t i n g h a i r growth and takes i n t o account among o t h e r s the c o n t r i b u t i o n of F r a s e r  (1934), K r i s h n a n (1939), Coop (1954), Van K o e t s v e l d (1954) and Ryder (195*0'  Bandy (1965) r e f e r s to c o n d i t i o n and behaviour of  the b l a c k t a i l e d deer as a f f e c t e d by the plane of n u t r i t i o n . C h i e f l y the r o l e of n u t r i t i o n has been s t u d i e d w i t h r e s p e c t to i t s e f f e c t on the r a t e of f i b r e p r o d u c t i o n and upon the chara c t e r i s t i c s of f i b r e s produced,  mechanism of h a i r l o s s and  the  p e r i o d of f o l l i c l e development. To document the e f f e c t of adverse n u t r i t i o n on the c e r v i d p i l a r y system an experiment were s t u d i e d .  was  designed and the r e s u l t i n g data  153 MATERIAL AND METHODS Four male b l a c k t a i l deer r a i s e d under i d e n t i c a l c o n d i t i o n s were s e l e c t e d .  These were Ul6, TR, U26 and W"4.  They were housed  under i d e n t i c a l c o n d i t i o n s i n the animal u n i t of the Department of  Zoology a t the U n i v e r s i t y o f B r i t i s h Columbia.  animals were maintained on U.B.C. r a t i o n 3 6 - 5 7 . Addison  A l l the (Table  22,23).  ( 1 9 6 5 ) has worked out the d i g e s t i b i l i t y of t h i s r a t i o n  (Table 2 3 ) and has determined  the c a l o r i f i c v a l u e of the r a t i o n  per gramme, as 3 » 1 3 6 . Animals U26 and W4 were put on an ad l i b i t u m d i e t and served as c o n t r o l s .  Ul6 and TR were used as experimental  animals and were put on a r e s t r i c t e d d i e t .  O r i g i n a l l y t h i s was  planned as 60% o f that consumed by the c o n t r o l animals, but t h i s did  n o t have any e a r l y e f f e c t s on the experimental animals,  perhaps due t o n u t r i t i o n a l r e s e r v e s i n the a n i m a l s .  The d i e t of  the experimental animals was t h e r e f o r e reduced u n t i l the f a t r e s e r v e s were exhausted and the animals evinced the s l u g g i s h behaviour accompanying m a l n u t r i t i o n . i n t a k e and weight  D e t a i l s of d a i l y  caloric  a t weekly i n t e r v a l s a r e g i v e n i n Appendix 1  and 2 . The e f f e c t o f adverse n u t r i t i o n on b l a c k t a i l pelage was s t u d i e d on a comparative animals.  b a s i s between c o n t r o l and experimental  TABLE 22 COMPOSITION OF ADULT RATION —  U.B.C. 36-57 Addison  Ingredient  (1965)  Amount  Corn meal  600 l b s .  Ground wheat  250 l b s .  bran  275 l b s .  Molasses  150 l b s .  Beet pulp  200 l b s  V i t a grass  200 l b s .  Soya bean meal  175 l b s .  H e r r i n g meal  110 l b s .  Bone meal  20 l b s  Iodised s a l t  20 l b s .  2000 l b s .  155  TABLE 23 NUTRIENT COMPOSITION OF RATION U.B.C.  36 - 57 Compared w i t h N.R.C.  REQUIREMENTS FOR GROWING SHEEP - Addison (l?6g) N.R.C. Nutrient  Units  Requirements! 36.3  U.B.C. 36 - 57 32  Digestible protein  mgm/cal3  Ca  mgm/cal  0.97  1.01  p  mgm/cal  O.87  I.63  Ia/cal  1.84  44  I./cal  0.5  44  2  Vitamin A Vitamin D  ,  1 - Calculated  from t o t a l d a i l y requirements f o r  a 60 l b . lamb. 2 - Crude p r o t e i n x 60% 3 - C a l o r i e s of apparent d i g e s t i b l e energy 4 - T o t a l c o n t r i b u t i o n from a l l r a t i o n i n g r e d i e n t not known but a p a r t i a l t o t a l exceeds the N.R.C. requirement.  156  TABLE 24 DIGESTIBLE ENERGY CONTENT OP THE ADULT RATION  Addison (1965)  TATION  ADULT  Gross e n e r g y Feed  faeces  4363  4136  1  Digestible _ energy Digestible % (Dry)  3  c  42 - 63$  171 t o 2873  Digestible^ energy (Air dry)  1518 t o 2543  1 - Gross energy i n c a l o r i e s /mg. 2 - % digestibility 3 - Digestible  energy i n calories/mgm of oven d r y feed  4 - Digestible  energy i n c a l o r i e s per mg o f a i r d r y  feed  (10$ moisture)  157 Once t h e normally growing w i n t e r coat reached i t s r e s t i n g stage, an a r t i f i c a l h a i r c y c l e was Induced by p l u c k i n g r e s t i n g h a i r s from s e l e c t e d body s i t e s on c o n t r o l ( U l 6 ) animals.  (W4) and experimental  Using the technique of i m m o b i l i z a t i o n and s k i n  b i o p s y sampling d e s c r i b e d i n e a r l i e r c h a p t e r s , I took samples e a r l i e r from these s i t e s .  T h e i r h i s t o l o g i c a l examination  me t o attempt a comparative  enabled  r e c o r d of h a i r growth i n w e l l f e d and  underfed a n i m a l s . The o b s e r v a t i o n s of p h y s i c a l c h a r a c t e r i s t i c s of h a i r ( l e n g t h diameter, c o l o u r a t i o n ) were made as per techniques described i n e a r l i e r chapters. "Mettler" balance.  Weight measurements were made on  The t e x t i l e chemistry s e c t i o n o f the N a t i o n a l  Research C o u n c i l , k i n d l y made some o b s e r v a t i o n s on t e n s i l e s t r e n g t h of h a i r s grown by w e l l f e d and underfed a n i m a l s .  The  f i b r e s were c o n d i t i o n e d and t e s t e d a t 70 ± 20°F and 65 - 2% R.H. The machine used was CRE ( I n s t r o n ) t e s t e r — 1 . 0 inch/min constant r a t e of specimen e x t e n s i o n , g i v i n g a b r e a k i n g time of r o u g h l y 20 - 25 seconds.  Machine c a p a c i t y used = 0 - 1.00 l b .  clamp s e p a r a t i o n s = 2 cms.  Initial  Root end o f f i b r e s p l a c e d i n the clamp.  OBSERVATIONS a) Normally grown w i n t e r pelage on c o n t r o l and experimental a n i m a l s . As soon as the e f f e c t of m a l n u t r i t i o n was f e l t the experirmental animals began chewing o f f l a r g e patches of h a i r on t h e i r sides.and by mid-winter thighs.  they had bare patches on f l a n k s and  These animals l a c k e d i n s u l a t i o n on l a r g e areas of body i n  w i n t e r and on p a r t i c u l a r l y c o l d days appeared  v i s i b l y a f f e c t e d as  158 m a n i f e s t by t h e i r s t i f f remaining body h a i r s .  g a i t and the f l u f f e d appearance  of the  In c o n t r a s t the c o n t r o l animals had  pelage and behaved n o r m a l l y .  normal  Towards e a r l y s p r i n g the bare  patches on the body of the experimental animals were covered by newly growing winter h a i r s , but b e f o r e they c o u l d a t t a i n any degree of l e n g t h they were chewed o f f a g a i n .  T h i s tendency t o  chew o f f the c o a t i n undernourished animals was a l s o n o t i c e d by Bandy ( 1 9 6 5 ) . who  d e t e c t e d i t i n f a l l and w i n t e r .  e x h i b i t e d the tendency throughout the y e a r .  My  animals  I t can impose an  added s t r e s s on animals l i v i n g under c o n d i t i o n s of w i n t e r  chill  and m a l n u t r i t i o n .  this  I t should not be assumed, however t h a t  behaviour occurs i n the w i l d where "roughage" m a t e r i a l , even i f of poor q u a l i t y may of  the a n i m a l s own 1  In ter  s u b s t i t u t e f o r the e a t i n g  hair.  the body a r e a where the pelage remained  i n t a c t the win-  coat of c o n t r o l animals d i f f e r e d from t h a t of the experimental  animals i n the f o l l o w i n g r e s p e c t s . was  i n the form of p l a n t  l o n g and s l e e k .  The coat of c o n t r o l animals  The experimental animals had shed the l a r g e  guard h a i r s and the overcoat c o n s i s t e d mostly of i n t e r m e d i a t e guard h a i r s and presented a rough appearance.  The h a i r s i n the  experimental animal were s h o r t e r and narrower than those of c o n t r o l animals, but appeared s t i f f e r than those i n c o n t r o l a n i m a l s . T h i s s t i f f n e s s can be a t t r i b u t e d t o g r e a t e r amount of c o r t i c a l t i s s u e v i s a v i s medulla i n experimental animals, s u g g e s t i n g t h a t undernourishment  a f f e c t s more medullary mass w i t h i n the h a i r s .  K r i s h n a n (1939) has suggested t h a t changes i n h a i r diameter due to adverse n u t r i t i o n are r e s u l t s from changes i n dimensions of medull a Ryder ( 1 9 5 6 ) , Coop (195*0 however f e e l t h a t both c o r t e x and  medulla are a f f e c t e d by undernourishment. t h a t i n deer medulla has h a i r diameters and observation  study suggests  the c r u c i a l r o l e to p l a y i n determining  thus c o r r o b o r a t e s  K r l s h n a n (1939)•  of undernourished deer d u r i n g  Vancouver I s l a n d  My  Field  severe w i n t e r s  on  (Cowan verbatim) suggested t h a t the h a i r s of  these animals broke o f f c l o s e to the body l e a v i n g the animal covered.  T h i s l e d to the p o s t u l a t e t h a t m a l n u t r i t i o n might  responsible for reducing  i t more v u l n e r a b l e  has  some study to t h i s i n sheep and  t i o n reduces the breaking  be  the p h y s i c a l p r o p e r t i e s of the h a i r  rendering given  ill  to normal a b r a s i o n .  Ryder  states that  and  (1958)  malnutri-  s t r e n g t h per u n i t c r o s s - s e c t i o n  and  makes the wool f i b r e s t h i n n e r . In order  to explore  t h i s p o s s i b i l i t y arrangements were made  w i t h the T e x t i l e Chemistry S e c t i o n of the D i v i s i o n of  Applied  Chemistry of the N a t i o n a l Research C o u n c i l of Canada. Tweedie and  Mr.  Mr.  A.S.  P. Sturgeon k i n d l y made some t r i a l t e s t s of  t e n s i l e s t r e n g t h on i n d i v i d u a l h a i r s taken from our  experimental  animals. Other evidences of imposed changes i n h a i r s t r u c t u r e sought i n l e n g t h , weight, diameter to l e n g t h and development of the c o r t e x and  i n the  was  relative  medulla i n the h a i r s of the  two  groups of animals. The  r e s u l t s were i n c o n c l u s i v e .  The  l a r g e guard h a i r s gave  r e s u l t s i n d i c a t i n g t h a t c o n t r o l h a i r s are a l i t t l e experimental h a i r s , thus supporting on intermediate  stronger  Ryder (1958) °ut  observations  guard h a i r s gave r e v e r s e r e s u l t s (Tables 25,  Thus c o n t r a d i c t o r y r e s u l t s were o b t a i n e d .  than  26).  To o b t a i n mean-  i n g f u l r e s u l t s very l a r g e number of h a i r s would have to be  tested  160  TABLE 25 BREAKING STRENGTH ( l b ) F i b r e s C o n d i t i o n e d and Tested a t  70 i 2°F and 65  ± 2%  R.H.  Large Guard H a i r s U26 F u l l D i e t  9.188  0.225 0.227  .Ul6 Reduced  0.207 0.257  0.281* 0.304  0.259  0.249 0.199 0.280* 0.180 0.243  0.249* 0.246  0.321* 0.271  0.263 0.250  0.274*  Av = 0.256  Diet  Av = 0.242  Average f o r 7 f i b r e s ( i . e . e x c l u d i n g f i b r e s = 0.240 which s l i p p e d )  Av = 0.232  Range f o r 10 f i b r e s  0.180 - 0.263  0.188 - 0.321  * F i b r e s s l i p p e d i n one clamp before r e a c h i n g breaking l o a d was r e l e a s e d f i b r e reclamped and extended t i l l  breaking,  l o a d was reached. TABLE 26 Intermediate U26 F u l l D i e t  0.133 0.139 0.153  0.163 0.140  0.136 0.119 0.184 0.129 0.133  Av = 0.144 l b . Range 0.119 - 0.184 l b .  Guard H a i r s Ul6 Reduced  0.199 0.209 0.202 0.202 0.218  Diet 0.182 0.195 0.208 0.183 0.169  Av = 0.197 l b .  Range 0.169 - 0.209 l b .  *Observations were a l s o made to evaluate e f f e c t of adverse n u t r i t i o n on f i b r e weight.  161  TABLE 27 Intermediate Guard H a i r s  U26  Ul6 15 I guard h a i r s  10 I guard h a i r s (Av. weight per f i b r e c a l c u l a t e d from t o t a l weight of sample) Fibre length (approx) Range Fibre  0.000457  Av - 52 mm - 46-58 mm 10  0.000314. !:  1  Av - 39 mm Range - 36-41 mm Fibre  15  *Thus weight of h a i r s as w e l l as l e n g t h i s g r e a t e r i n w e l l f e d animals than i n s t a r v e d a n i m a l .  162 and t h i s was n o t p o s s i b l e . H a i r samples c o l l e c t e d from the rump r e g i o n o f w e l l f e d and underfed animals were c o l l e c t e d when they were i n t h e i r w i n t e r coat.  R e g r e s s i o n a n a l y s i s was done on the l e n g t h and diameter  data c o l l e c t e d .  I n the w e l l f e d animals the h a i r l e n g t h v a r i e d  from 28.00 mm t o 75*00 mm as a g a i n s t 23 mm t o 52 mm i n the underThe diameter v a r i a t i o n was 117 microns t o 277 microns.  fed. the  In  underfed animals the diameter v a r i e d from 92 t o 235 microns. R e g r e s s i o n a n a l y s i s however r e v e a l e d t h a t i n underfed  animals though the a c t u a l mean diameter was l e s s there was a r e l a t i v e i n c r e a s e i n diameter f o r any g i v e n l e n g t h . appear  I t would thus  t h a t w i t h l i m i t e d n u t r i e n t s growth i n h a i r diameter enjoys  a h i g h e r p r i o r i t y than growth i n l e n g t h .  T h i s i s i n consonance  w i t h the b e l i e f t h a t h a i r s w i t h g r e a t e r diameter not o n l y p r o v i d e cover but a l s o b e t t e r i n s u l a t i o n greater medulla). At  (as they p r o p o r t i o n a t e l y possess  :,  t h i s stage the p o s s i b i l i t y of v a r i a t i o n i n h a i r  length  and diameter i n the b l a c k t a i l deer forms, occupying d i f f e r e n t c l i m a t e areas was a l s o i n v e s t i g a t e d .  For t h i s purpose b l a c k t a i l  pelage samples were o b t a i n e d from Southern C a l i f o r n i a and A l a s k a . H a i r s from i d e n t i c a l r e g i o n s were compared w i t h B r i t i s h forms as r e g a r d s h a i r l e n g t h and diameter.  Columbian  The Southern  Califor-  n i a n form i n h a b i t i n g warm and d r y areas was found to possess h a i r s which were c o n s i d e r a b l y s m a l l e r i n diameter, and s h o r t e r .  The  form i n A l a s k a ( s l t k e n s l s ) presented the g r e a t e s t diameter.  The  h a i r l e n g t h was however not a p p r e c i a b l y g r e a t e r than t h a t found i n the  B r i t i s h Columbian  variety.  The c o n s i s t e n t i n c r e a s e i n h a i r  diameter from Southern C a l i f o r n i a t o A l a s k a a g a i n underscores i t s  80T  TO  —i—i—i—i—i—i—i—i—i—i—\—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i—i  i i i  R G . 5 5 WINTER COAT (RUMP)HAIR L E N G T H AND DIAMETER RELATIONSHIP UN CHANGING IH'ABTTAT  •  • • o  •  o  i i i i  i  i  <~-  •  ©or so • i K  D  O  0  '410}  3 0  o o  o o o°  i(o=  20  40  60  SO  1100  o  o  o  S .  C A L I F O R N I A  120  •  • i  140  (a  FORM )  i i  160  i  180  i  i_  200  = B R I T I S H  220  COLUMBIA  240  *  FORM)  260  * • i 280  (m  =  ALASKAN  i i i  300  320  1_  FORM )  _l  340  I  360  L_  380  400  DIAMETER, MICRONS  H  ON NJJ  164 importance  i n p r o v i d i n g adequate i n s u l a t i o n t o the a n i m a l ,  b) The a r t i f i c i a l l y  induced h a i r  cycles.  The a r t i f i c i a l h a i r c y c l e was s t a r t e d by p l u c k i n g r e s t i n g h a i r s from the t h i g h r e g i o n of the c o n t r o l ( U l 6 ) animals.  (w4) and experimental  Most of the guard h a i r s were easy t o p l u c k .  w o o l l y h a i r s were d i f f i c u l t  The  to p l u c k — i n the sense t h a t most of  them broke a t the s u r f a c e , l e a v i n g p a r t embedded  i n the f o l l i c l e .  The new h a i r c y c l e study was thus c o n f i n e d t o guard  hairs.  F o r t n i g h t l y o b s e r v a t i o n s on the plucked s i t e s on c o n t r o l and experimental animals d i d r e v e a l that n u t r i t i o n had an e f f e c t on emergence of new h a i r s on plucked s i t e s .  Although h a i r s were  plucked on c o n t r o l and experimental animals on the same day i . e . 1st  November  1966, the time a t which the new h a i r s emerged on  the s u r f a c e were d i f f e r e n t .  In the c o n t r o l animal they emerged  i n 60 days w h i l e i n experimental animal they emerged i n 90 days. The r e s t i n g stages were reached i n W"4 by mid-March and t h a t i n Ul6  by m i d - A p r i l , i n the plucked s i t e s .  growth p e r i o d ( a r t i f i c i a l l y  Thus the d u r a t i o n of the  induced) i s s i m i l a r t o t h a t i n normal  h a i r c y c l e and d i d not d i f f e r between the experimental c o n t r o l animals.  Lowenthal  and Montagna (1955) found t h a t i n mice "when  the h a i r s a r e p l u c k e d a t the time when the animals a r e p l a c e d on reduced d i e t the f o l l i c l e s  remain q u i e s c e n t f o r as l o n g as two  months but they become a c t i v e on the very day the animals a r e g i v e n ad l i b i t u m f o o d " . My experimental animals were p l a c e d on reduced d i e t f o r some time before the a r t i f i c i a l h a i r c y c l e was a c t u a l l y and d u r i n g the experiment  started  a t no time were they g i v e n ad l i b i t u m  Artificially  induced h a i r c y c l e  FIGURE 5 6 . 1 Plucked f o l l i c l e s regrowing i n underfed animal ( U l 6 ) f i r s t week. N o t i c e the rounded dermal p a p i l l a , enveloping f o l l i c l e base and cord of u n d i f f e r e n t i a t e d c e l l s above i t . L o n g i t u d i n a l s e c t i o n . H. & E. FIGURE 5 6 . 2 Plucked f o l l i c l e s regrowing i n w e l l f e d animal (W4) f i r s t week. Note the appearance o f plucked follicle. L o n g i t u d i n a l s e c t i o n . H. & E.  FIGURE 5 7 H a i r s emerging a f t e r f o u r weeks i n w e l l f e d animal ( W 4 ) . Transverse s e c t i o n . H. & E. FIGURE 5 8 H a i r s a c t i v e l y growing two months a f t e r p l u c k i n g i n underfed animal ( U l 6 ) . Longitudinal section. H. & E. For e x p l a n a t i o n of a b b r e v i a t i o n s see Appendix IV, Page 2 1 4 .  used  please  166  167 diet.  At one  stage  (mid-Dec. 1966)  c o n d i t i o n of U l 6 , h i s d i e t was t h i s i n c r e a s e i n d i e t may  owing t o c o n s i d e r a b l y weakened  increased.  I t i s conceivable that  have t r i g g e r e d the h a i r growth c y c l e  e a r l i e r than i t would have otherwise  started.  In both the animals h a i r s grew c o n s i d e r a b l y l o n g e r i n the v i c i n i t y of the b i o p s y s i t e s than elsewhere Ebling  on the plucked a r e a .  (1964) f i r s t r e p o r t e d t h a t h a i r s a t t a i n g r e a t e r l e n g t h s a t  the s i t e of wounds and sutures d u r i n g h i s work on h a i r growth. T h i s can now  be confirmed a l s o f o r deer.  The h a i r s growing  In the plucked areas were of w i n t e r type  but d i d not e x h i b i t the m e t a l l i c grey c o l o u r a t i o n i n e a r l y of  stages  growth so c h a r a c t e r i s t i c of the e a r l y stages of a normally  grown w i n t e r c o a t , i n s t e a d they were l i g h t - b r o w n i n c o l o u r .  Here  too the h a i r s i n experimental animals were of s m a l l e r l e n g t h and diameter than those of the c o n t r o l a n i m a l s .  The d i f f e r e n c e i n  c o l o u r a t i o n of the e a r l y phases of a r t i f i c i a l l y (growing i n Nov.  - Dec.)  induced h a i r s  and n o r m a l l y growing w i n t e r h a i r s  (August to Sept.) c o u l d be a t t r i b u t e d to s u b t l e b i o c h e m i c a l changes w i t h i n the h a i r f o l l i c l e as i t prepares i t s e l f  f o r the  p r o d u c t i o n of normal summer h a i r s . c) H i s t o l o g i c a l changes d u r i n g the a r t i f i c i a l h a i r When the experiment  was  s t a r t e d on November 1,  w i n t e r coat had f i n i s h e d growing and a l l the primary  cycle  1966,  the  follicles  were i n t e l o g e n . In  the b l a c k t a i l e d deer t h i s stage i s s i m i l a r t o t h a t  found i n the mouflon,  Ryder (1966).  The f o l l i c l e  ceases  produc-  t i o n of medulla and the b a s a l h a i r p a r t i s consequently devoid of it.  The r e s t i n g h a i r f o l l i c l e  i s p u l l e d towards the s k i n s u r f a c e  FIGURE 59 Well f e d animal I n winter  coat.  FIGURE 6 0 Underfed animal i n winter c o a t . N o t i c e coat chewed o f f on s i d e s r e s u l t i n g i n bare patches and rough appearance of the c o a t . FIGURE 6 1 H a i r s growing f a s t e r i n the v i c i n i t y o f s k i n b i o p s y a r e a s . Notice the sampling s i t e s .  FIG 61  FIG.62 WINTER COAT GUARD HAIR (BACK) L E N G T H AND DIAMETER R E L A T I O N S H I P IN W E L L FED A N I M A L ( S C A T T E R G R A M )  20h  I0 '  80  "  100  •  1  120  1  "  140  1  1  160  1  1  180  1  i  200  D I A M E T E R , MICRONS  i  i  220  •  •  240  i  i  260  i  I  280  80 FIG.63 WINTER COAT G U A R D HAIR ( B A C K ) L E N G T H AND DIAMETER R E L A T I O N S H I P IN U N D E R F E D A N I M A L ( S C A T T E R G R A M ) 70  60  50  o z 40  30  20 -  10 80  100  120  140  160  180  200  D I A M E T E R , MICRONS  220  240  260  280  1000  10  20  30  40  LENGTH , MM FIG.64 REGRESSION LINES COMPARING L E N G T H AND DIAMETER RELATIONSHIP B E T W E E N WELL F E D AND U N D E R F E D WINTER COAT GUARD HAIR SAMPLES  173 and  the h a i r base l i e s near the v i c i n i t y of the a r r e c t o r  muscle attachment.  The h a i r base has a brush end and i s enclosed  i n an epidermal c a p s u l e .  The f o l l i c l e base i s connected to the  h a i r base by a c o r d of u n d i f f e r e n t i a t e d c e l l s . hair f o l l i c l e  i s g r e a t l y reduced i n s i z e .  rounded and h a l f enclosed it  pilii  by the b u l b .  The b u l b of the  The dermal p a p i l l a i s  In r e l a t i o n t o the bulb  i s p r o p o r t i o n a t e l y g r e a t e r than t h a t found i n a c t i v e l y growing  follicles.  The c e l l s a t the base o f the f o l l i c l e c o v e r i n g the  dermal p a p i l l a a r e much l a r g e r and prominently n u c l e a t e d . melanocytes a r e a l s o present w i t h i n t h i s r e g i o n . has  The f o l l i c l e  l o s t i t s i n n e r r o o t sheath and the epidermal capsule  e x t e r n a l r o o t sheath o r i g i n . p a p i l l a a r e enclosed  i s of  The f o l l i c l e as w e l l as dermal  by a l a y e r of c e l l s o f connective  T h i s l a y e r i s separated  Some  tissue.  from e x t e r n a l r o o t sheath by a g l a s s y  membrane v i s i b l e a t p l a c e s .  G e n e r a l l y the p a r t s of the r e s t i n g  f o l l i c l e s l y i n g below the attachment of a r r e c t o r p i l i i  muscle  are s t r a i g h t but o f t e n g e t bent s l i g h t l y t o one s i d e . When the h a i r s were plucked  out a t t h i s stage the remaining  e x t e r n a l r o o t sheath was p u l l e d out and mostly d e s t r o y e d . connective present and  The  t i s s u e elements as w e l l as the g l a s s y membrane a r e  i n the f o l l i c u l a r r e g i o n .  The process  of r e g e n e r a t i o n  r e p a i r s t a r t s immediately and w i t h i n a week the bulbs  f o l l i c l e s have descended t o lower depths.  of the  The cord of the u n d i f -  f e r e n t i a t e d c e l l s above the bulb has i n c r e a s e d i n l e n g t h and i s the cause of t h i s e l o n g a t i o n . and  i s mostly enclosed  The dermal p a p i l l a has.been rounded  by the f o l l i c l e b u l b .  The melanocytes a r e  no longer r e s t r i c t e d t o l a y e r s immediately above the dermal p a p i l l a but none occur along the l e n g t h of the growing  follicle.  174 The newly d e v e l o p i n g f o l l i c l e i s o f t e n t w i s t e d a l o n g i t s l e n g t h . In a 4 t h week sample the f o l l i c l e b u l b has become e n l a r g e d and the dermal c e l l elements a r e rounded.  The dermal p a p i l l a i s  e n c l o s e d by the f o l l i c l e bulb, which i n t u r n has reached the l e v e l of the sweat gland ( d i s t a l end). i n the 5th week a l s o .  The same s t a t e continues  Blood v e s s e l s a r e p r e s e n t i n the p a p i l l a  and a membrane separates the f o l l i c l e c e l l s from the p a p i l l a  cells.  By the 6th week the l a r g e guard h a i r s have emerged on the s u r f a c e . These f o l l i c l e s grow a t a f a s t e r r a t e than the i n t e r m e d i a t e guard hair f o l l i c l e s .  In the w e l l f e d animals the r e g e n e r a t i o n process  s t a r t s immediately and the the 4 t h week l a r g e guard h a i r s a r e emerging follicles  on the s u r f a c e .  I n the underfed animals most of the  experience a r r e s t e d growth a f t e r r e a c h i n g the stage when  they produce a l o n g c o r d o f u n d i f f e r e n t i a t e d c e l l s w i t h f o l l i c l e b u l b e n c l o s i n g three f o u r t h s of dermal  papilla.  Summary Underfed animals have s h o r t e r and more s l e n d e r h a i r s than w e l l f e d c o n t r o l s ; the h a i r s a l s o weigh l e s s .  There i s n o n - c o n s i s -  t e n t demonstrable d i f f e r e n c e i n t e n s i l e s t r e n g t h of h a i r s from c o n t r o l and experimental a n i m a l s .  A l s o undernourishment  seemed t o  have no e f f e c t on the percentage of w o o l l y undercoat. Woolly under h a i r s a r e d i f f i c u l t  t o pluck, s i n c e d u r i n g the  attempted p l u c k i n g they get broken o f f a t the s k i n s u r f a c e .  The  h a i r c y c l e induced a r t i f i c i a l l y by p l u c k i n g h a i r s i s mainly concerned w i t h guard h a i r s .  The r e g e n e r a t i o n of plucked  follicles  s t a r t s immediately, but i n the underfed animal appears t o have been a r r e s t e d f o r a l o n g e r time i n a t r a n s i t i o n a l stage.  In  175 c o n t r o l animal the f o l l i c l e r e g e n e r a t i o n and h a i r development i s f a s t e r , and t h a t of the l a r g e guard h a i r s i s f a s t e r than t h a t of the  i n t e r m e d i a t e guard h a i r f o l l i c l e .  In c o n t r o l animal the  l a r g e guard h a i r s have begun t o emerge on the s u r f a c e i n the 4 t h week and by the 6 t h week most of the other guard h a i r s have emerged.  In experimental animals the l a r g e guard h a i r s emerge by  the 6 t h week and the r e s t by the 8 t h week. Experimental animals were observed t o chew o f f h a i r s on the body; t h i s gave r i s e t o bare patches on the f l a n k s .  176 Chapter V I I I G-ENERAL DISCUSSION The f a m i l i e s c e r v i d a e and bovidae are the two major groups i n the wide and d i v e r s e assemblage of the e x i s t i n g (Simpson 1 9 ^ 5 ) .  ungulates  However knowledge of the ungulate p i l a r y  has been v i r t u a l l y c o n f i n e d to the Bovid genera Bos, Capra.  system  Ovls, and  I t i s t h e r e f o r e of p a r t i c u l a r i n t e r e s t to compare the  i n f o r m a t i o n on these w i t h the d e t a i l s from a c e r v i d form i . e . Odocolleus hemlonus columbianus,  and t o see whether any  signifi-  cant e v o l u t i o n a r y or a d a p t i v e trends emerge. Follicle  development and Anatomy  E m b r y o l o g i c a l l y the c e r v i d f o l l i c l e development f i t s  into  the g e n e r a l mammalian p a t t e r n ; and goes through the same developmental was  stages.  U n f o r t u n a t e l y no known-aged s e r i e s of deer f o e t u s e s  a v a i l a b l e , and to develop such a s e r i e s would have i n v o l v e d a  long-range  s p e c i a l breeding programme.  Consequently no  comparisons  on the t i m i n g of stages of f o l l i c l e development or emergence of h a i r s on the body, have been made w i t h other u n g u l a t e s .  However  these have been r e l a t e d to d e s i g n a t e d s i z e stages i n embryogeny. As the regards the development and the r e l a t i v e s i z e of the cle  a c c e s s o r i e s the deer resembles  domestic  sheep.  folli-  The s e c r e t o r y  p o r t i o n of the deer sweat gland , however, i s q u i t e sinuous. T h i s i s not so i n sheep or c a t t l e , and i n the l i g h t of present knowledge appears  to be a unique c e r v i d f e a t u r e .  Sokolov  (1963)  s t a t e s t h a t i n w i l d a r t i o d a c t y l of U.S.S.R. some sweat glands disappear completely d u r i n g the w i n t e r and the s e c r e t o r y p o r t i o n  177 of  the o t h e r s i s reduced. No such seasonal changes i n these glands have been encoun-  t e r e d i n Odocoileus hemionus columbianus.  and the sweat gland  f e a t u r e s remain c o n s t a n t . In  the genera  s t u d i e d by Sokolov  i t would, however, be of  i n t e r e s t t o document i n d e t a i l the redevelopment of a sweat gland that had r e g r e s s e d d u r i n g the p r e v i o u s w i n t e r .  I t i s not s t a t e d  if  the sweat gland r e f e r r e d above are of e c c r i n e or a p o c r i n e type.  In  Odocolleus they a r e a l l a p o c r i n e type. In  is  Odocolleus, as i n c a t t l e ,  sheep and goats, each  follicle  a s s o c i a t e d with no more than one sebaceous gland and t h i s may  be completely m i s s i n g i n some of the s m a l l e s t f o l l i c l e s .  In  l a r g e r f o l l i c l e s the sebaceous gland i s o f t e n b i l o b e d ; but no d i s t i n c t i v e a c i n i i have been observed  i n these l o b e s .  ( 1 9 6 3 ) s t a t e s t h a t the number of sebaceous glands v a r i e s from one t o t h r e e .  Sokolov  a t each h a i r  T h i s i s not so i n Odocolleus, but l i k e  A l c e s the sebaceous glands i n Odocoileus do appear t o be more developed  and enlarged i n summer.  role during t h i s  T h i s may I n d i c a t e a more a c t i v e  season.  The h a i r f o l l i c l e s of Odocolleus. sheep, and goats have been c l a s s i f i e d i n t o p r i m a r i e s and s e c o n d a r i e s .  The p r i m a r i e s can be  f u r t h e r d i v i d e d i n t o c e n t r a l p r i m a r i e s and l a t e r a l p r i m a r i e s . A l l the p r i m a r i e s a r e a s s o c i a t e d with sweat gland, sebaceous gland and A. p i l i i  muscle.  The secondaries have i n t u r n been d i v i d e d  f i r s t formed and l a t e r formed.  The f i r s t formed secondaries are  l a r g e r , as i n goats, mouflon, and some domestic The  into  sheep breeds.  Odocolleus d i f f e r s from these i n the p o s s e s s i o n of a sweat  gland, and an A. p i l i i  muscle i n a d d i t i o n to the sebaceous g l a n d .  178 T h i s has not been r e c o r d e d b e f o r e .  Such an occurrence, however,  r a i s e s doubts about the v a l i d i t y of the standard c h a r a c t e r i s t i c s d i s t i n g u i s h i n g a primary from a secondary f o l l i c l e . q u e s t i o n whether there i s a t a l l : any fundamental secondary f o l l i c l e t y p e s . stages of continuum,  primary and  I t i s p o s s i b l e t h a t they a r e d i f f e r e n t  reflecting,  i n t h e i r s i z e and morphology, the  g r a d u a l d e p l e t i o n of the f o l l i c l e - f o r m i n g substance. c a t t l e each o f the h a i r f o l l i c l e s ceous gland and A. p i l i i muscle; d i f f e r e n t s e q u e n t i a l ages. f i r s t formed,  I t r a i s e s the  In case of  possesses a sweat gland, sebabut the f o l l i c l e * s develop a t  Consequently they have been c a l l e d  l a t e r formed and l a s t formed,  By accepted d e f i n i -  t i o n however they a l l a r e homologous t o the primary  follicles,of  sheep, goats and deer. A n a t o m i c a l l y a l l the b a s i c c e l l l a y e r s c o n s t i t u t i n g the f o l l i c l e s a r e common t o the u n g u l a t e s . are  noteworthy  f o r Odocoileus.  The f o l l o w i n g f e a t u r e s  The e x t e r n a l r o o t sheath i s w e l l  developed and uniform around the f o l l i c l e as opposed t o sheep where i t i s b e t t e r developed on the e n t a l s i d e .  U n l i k e sheep i n  deer the g l a s s y membrane i s a l s o o f t e n c l e a r l y v i s i b l e i n the b a s a l b u l b r e g i o n , where the e x t e r n a l r o o t sheath i s c o n s i d e r a b l y reduced.  I n Odocolleus  an a d d i t i o n a l g l a s s y membrane o c c u r s  between the e x t e r n a l and i n t e r n a l r o o t sheath. r e p o r t e d i n sheep, goat or c a t t l e . know how widespread  T h i s has not been  I t would be i n t e r e s t i n g t o  t h i s c h a r a c t e r i s t i c i s among the c e r v i d a e and  its functional u t i l i t y .  Henle's l a y e r of i n n e r r o o t sheath i s  l a r g e and s t a i n s more h e a v i l y w i t h Haematoxylin and E o s i n than the a d j o i n i n g Huxley's l a y e r l y i n g on i t s inner s i d e . are  Both  s i n g l e c e l l e d but i n the l a t t e r the c e l l s a r e s m a l l e r .  layers In  179 deer Henle's l a y e r i s of uniform t h i c k n e s s u n l i k e that i n sheep where i t i s t h i c k e r on the e n t a l  side.  The d e v e l o p i n g primary f o l l i c l e s  i n Odocolleus are char-  a c t e r i z e d by the presence of an e n t a l s w e l l i n g . observed t o I n d i c a t e t h a t the A. p i l i i with i t .  No evidence  was  muscle had a n y t h i n g to do  My o b s e r v a t i o n s support Lyne and Heideman's  (1959)  c o n t e n t i o n t h a t there i s no c a u s e - a n d - e f f e c t r e l a t i o n s h i p between the e n t a l s w e l l i n g and the A. p i l i i  muscle.  There was  however a  c o n s i s t e n t r e l a t i o n s h i p between t h i s muscle and the sweat gland  —  they always o c c u r r e d t o g e t h e r . As i n c a t t l e the t r i o f o l l i c l e grouping i s c l e a r l y i n the developmental ly  stages but gets somewhat obscured  apparent  subsequent-  owing to growth of the body and r e s u l t a n t s t r e t c h i n g of the  skin.  In deer the f i r s t formed  secondary f o l l i c l e s  than i n the goat and a f o l l i c l e grouping of f i v e and two f i r s t formed  are l a r g e r  (three p r i m a r i e s  s e c o n d a r i e s ) becomes prominent.  a l s o been observed i n goat, mouflon, sheep, but not i n c a t t l e .  T h i s has  and some breeds of domestic  In sheep the secondary f o l l i c l e  group  i s l o c a t e d e n t i r e l y between the p r i m a r i e s , but i n deer and  goats  it  i s o n l y wedged between the p r i m a r i e s .  formed  In goats the  first  secondary f o l l i c l e forms the apex of t h i s wedge but t h i s i s  not always the case i n deer. In  the course of the h a i r f o l l i c l e development i n Odocolleus  some of the c e n t r a l p r i m a r i e s f o l l o w a d i f f e r e n t path.  They are  only a stage or two ahead i n development i n r e s p e c t of other c e n t r a l primary f o l l i c l e s a t t a i n large s i z e . mm  foetus.  but grow a t a much f a s t e r r a t e and  T h i s i s p a r t i c u l a r l y obvious i n a 2 6 9 and 2 8 7  O c c a s i o n a l l y the neck r e g i o n of these f o l l i c l e  appear  180 bulbous, but no d e f i n i t e s i n u s has been d e t e c t e d t h e r e .  These  f o l l i c l e s are v e r y s i m i l a r to the t y l o t r l c h s d i s c u s s e d by  Straile  ( 1 9 6 1 ) and are m o r p h o l o g i c a l types l y i n g i n between the v i b r i s s a f o l l i c l e and the normal h a i r f o l l i c l e . cle  The d i s c r e p a n c y i n f o l l i -  s i z e i s n o t i c e a b l e p r e n a t a l l y , but subsequently these  cannot be d i s t i n g u i s h e d c l e a r l y from other a d j o i n i n g follicles. —  These s p e c i a l i z e d f o l l i c l e s produce  obvious on the s k i n s u r f a c e of 287 mm  c a l l e d l a r g e guard h a i r s . by t h e i r l e n g t h —  foetus.  apart.  i n animals —  hair  These have been identified  Their stimulation  thus g i v i n g  the suspected sensory nature of the f o l l i c l e s Flerov  a l o n g guard  which i s 1 V 2 times longer than other guard  produces a t w i t c h i n g response  arise.  primary  In a d u l t pelage they can be  h a i r s ; and occur s c a t t e r e d about 2 . 5 mm  to  follicles  support  i n which they  ( i 9 6 0 ) r e f e r s to l a r g e guard h a i r s o c c u r r i n g i n  c e r v i d forms l i k e Dama, Capreolus, but makes no r e f e r e n c e to t h e i r development or l i k e l y  function.  In c a t t l e about  s i x percent of  h a i r f o l l i c l e s have been r e p o r t e d t o be of g i a n t s i z e a t m a t u r i t y and not d u r i n g development. f u n c t i o n of h a i r s produced  There are no data on the types or by these f o l l i c l e s .  no r e f e r e n c e t o such f o l l i c l e s  or h a i r s was  In goat and  noticed.  My  sheep,  observa-  t i o n thus probably are the f i r s t d e f i n i t i v e account of the d e v e l opment and l i k e l y  f u n c t i o n of the l a r g e guard h a i r s i n u n g u l a t e s .  They appear to be c h a r a c t e r i s t i c of f o r e s t - i n h a b i t i n g c e r v i d s but not of the p l a i n s and uplands d w e l l i n g ovlnae and c a p r i n a e . The p r i m a r i e s and f i r s t formed secondaries i n deer medullated h a i r s . hairs. of  form  Those a r i s i n g i n p r i m a r i e s c o n s t i t u t e the guard  The f i r s t formed s e c o n d a r i e s g i v e r i s e to medullated  t r a n s i t i o n a l type present o n l y i n the f i r s t fawn p e l a g e .  hairs The  181 other s e c o n d a r i e s g i v e r i s e to non medullated w o o l l y under h a i r s . Some of the n a t a l primary f o l l i c l e s  i n s t e a d of producing normal  guard h a i r s g i v e r i s e i n the fawn b i r t h coat, to white t i p p e d h a i r s c h a r a c t e r i s t i c of the white s p o t s . the subsequent  These same f o l l i c l e s i n  h a i r c y c l e s produce normal guard h a i r s .  Thus the  primary f o l l i c l e s are capable of producing d i f f e r e n t h a i r d u r i n g the animal's l i f e span. merino where f o l l i c l e s  types  T h i s has been shown to occur i n  f i r s t producing medullated h a i r s , i n l a t e r  non medullated h a i r s , Wildman (1937)'  h a i r c y c l e s produce  The dermal p a p i l l a e v a r y w i t h the type of h a i r being produced, they are s p a t u l a t e i n h e a v i l y medullated h a i r s and have a p o i n t e d apex i n h a i r s having s m a l l medulla or no medulla a t a l l . In  the f o l l i c l e s producing white t i p p e d h a i r the dermal  however has a p o i n t e d apex.  papilla  A l s o i n the white t i p p e d h a i r s the  c o r t e x i s r e l a t i v e l y w e l l developed v i s a v i s the medulla and  the  medulla i t s e l f l a c k s the i n t r a c e l l u l a r c a v i t i e s present i n other deer guard h a i r s .  T h i s i s a unique Odocoileus f e a t u r e and not  r e c o r d e d f o r other u n g u l a t e s . The d u r a t i o n of h a i r f o l l i c l e development i s a l s o v a r i a b l e with f o l l i c l e types.  Lyne (1965) s t a t e s t h a t i t i s i n v e r s e l y  p r o p o r t i o n a l to the mature s i z e of the h a i r f o l l i c l e .  This i s  t r u e f o r deer guard h a i r s where the s m a l l e r guard h a i r s come t o r e s t e a r l i e r than the l a r g e guard h a i r s . follicles  pose a problem.  But the deer  secondary  The f i r s t formed secondaries behave  l i k e s m a l l e r p r i m a r i e s , and precede them i n coming t o r e s t .  The  l a t e r formed s e c o n d a r i e s , which are s m a l l e r i n s i z e f o l l o w a c y c l e of  t h e i r own  and have no r e l a t i o n s h i p w i t h the primary and  formed secondary.  A l l primary f o l l i c l e s and f i r s t formed  first second-  a r i e s are w e l l formed a t b i r t h and are f u n c t i o n a l , the l a t e r  182 formed secondaries continue to form post n a t a l l y and become f u n c t i o n a l o n l y i n the fawn w i n t e r c o a t .  T h i s does not however  i n c r e a s e the f o l l i c u l a r d e n s i t y i n the p o s t n a t a l s t a g e s . i n c r e a s e i n body s i z e and r e s u l t i n g d i l u t i o n of f o l l i c l e t i o n more than compensates f o r the new  popula-  s e c o n d a r i e s being formed.  Ryder (1966) s t a t e s t h a t i n goats the f i r s t formed"hairs r e s t i n g stage f i r s t .  As  reached  T h i s i s of g r e a t i n t e r e s t as i t c o n t r a d i c t s  the normal t r e n d of events i n u n g u l a t e s .  A l s o i n deer the r a t e of  f o l l i c l e growth, as opposed t o the r a t e of f o l l i c l e development, is variable i n different f o l l i c l e s . follicles  Thus the l a r g e guard  though o n l y a stage or two ahead of t h e i r  hair  contemporaries  i n development are none the l e s s much longer (at l e a s t i n f o e t a l m a t e r i a l ) and t h i s can o n l y be brought cell division.  The f a c t o r s r e s p o n s i b l e f o r t h i s d i f f e r i n g growth  r a t e are not w e l l known.  The v a r i o u s h a i r f o l l i c l e s are i n c l o s e  p r o x i m i t y of each other and some s u b t l e  the governing f a c t o r s must operate i n  way.  Paired f o l l i c l e s i n the deer.  about by a f a s t e r r a t e of  present i n c a t t l e have a l s o been d e t e c t e d  These g e n e r a l l y are c o n f i n e d to l a t e r formed  s e c o n d a r i e s , one  of which i s of l a r g e r s i z e .  These  follicles  a r i s e independently very near each other but the h a i r s produced them emerge through a common a p e r a t u r e .  T h i s has not been r e c o r d -  ed f o r sheep or g o a t s . Branching f o l l i c l e s  i n v o l v i n g three t o f o u r secondaries of  s u c c e s s i v e l y s m a l l e r s i z e a r i s i n g from a l a t e r formed have a l s o been r e c o r d e d i n deer. present i n sheep and g o a t s . p a r t i c u l a r l y w e l l developed  by  These are absent  secondary  i n c a t t l e but  Branching of the secondaries are i n merino sheep where upto  s i x or  1 8 3  seven wool f i b r e s may  emerge from a f o l l i c u l a r  aperture.  However  i n as much as t h i s c o n d i t i o n has not been r e p o r t e d f o r w i l d sheep, i t must be regarded as a mutation s e l e c t e d d u r i n g g e n e r a t i o n s of husbandry. to  The normal ungulate p a t t e r n i s f o r not more than  three h a i r s , from simple branched  single aperture.  follicles  two  t o emerge from a  In a d d i t i o n the merino s k i n , u n l i k e any Jbhat -  of  other ungulate, i s g r e a t l y f o l d e d , which i n c r e a s e the number  of  follicles  Epidermis and  on the body. dermis  During the course of f o l l i c l e development the epidermis and the dermis undergo c e r t a i n changes. r e t i c u l a r l a y e r s of the dermis some may  The c o l l a g e n f i b r e s i n the  i n c r e a s e i n s i z e and w i t h m a t u r i t y  even be formed i n the p a p i l l a r y l a y e r .  In the epidermis  the stratum spinosum i n c r e a s e s i n s i z e as f o l l i c l e s are formed but a t m a t u r i t y i s h a r d l y d i s t i n g u i s h a b l e as a d i s c r e t e lamina as there i s a continuum of c e l l s from the b a s a l l a y e r t o the p e e l i n g stratum corneum.  Sokolov  ( 1 9 6 3 )  s t a t e s that the dermis, and i n  p a r t i c u l a r i t ' s p a p i l l a r y l a y e r , i s t h i c k e r i n summer than i n winter.  T h i s i s a l s o t r u e of the stratum spinosum.  corneum however behaves i n r e v e r s e f a s h i o n .  Stratum  T h i s has not been  d e f i n i t i v e l y established i n Odocolleus. Ling  ( 1 9 6 5 )  s t a t e s t h a t most of the animals undergo a moult  p r e n a t a l l y or immediately a f t e r b i r t h . i n d i c a t i o n of t h i s i n O d o c o l l e u s . development the  There was  never  any  Of course d u r i n g embryonic  'periderm' i s sloughed and r e p l a c e d by the stratum  corneum, but h a i r s are not y e t present a t t h i s  time.  184 H a i r types and morphology The deer i n course of i t s l i f e c y c l e bears f o u r c h a r a c t e r istic," . coats .  When the b l a c k t a i l fawns a r e born i n summer they  bear the b i r t h c o a t . The  T h i s coat has summer coat c h a r a c t e r i s t i c s .  important p o i n t of d i f f e r e n c e being that here there i s a  d i s t i n c t i v e undercoat. the w i n t e r c o a t .  I n a d u l t deer i t i s o n l y r e s t r i c t e d t o  A l s o the h a i r s c o n s t i t u t i n g the b i r t h coat  undercoat a r e mostly of t r a n s i t i o n a l type and have fragmental medulla.  (and not true w o o l l y )  They a r i s e i n the s m a l l e r of the  primary f o l l i c l e s and the f i r s t  formed s e c o n d a r i e s .  The l a t e r  formed s e c o n d a r i e s which g i v e r i s e to the non medullated w o o l l y under h a i r of the fawn and a d u l t w i n t e r coat a r e s t i l l and not f u n c t i o n a l .  forming  As many of the b i r t h coat undercoat  hairs  a r i s e i n primary h a i r f o l l i c l e s and as i t i s p r e s e n t i n a summer type of pelage i t may be c o n s i d e r e d i n p a r t homologous t o c a t t l e undercoat.  In c a t t l e a l l the h a i r f o l l i c l e s a r e s t r u c -  t u r a l l y comparable t o the primary f o l l i c l e s of deer, sheep and goat, and the undercoat winter pelages.  i s present g e n e r a l l y i n both summer and  The p o i n t s of d i f f e r e n c e b e i n g t h a t i n c a t t l e  the undercoat h a i r s a r i s e i n f o l l i c l e s homologous to deer primary f o l l i c l e s and a r e a l l non medullated. The presence o f an undercoat  They a r e not woolly.  i n an e s s e n t i a l l y summer type of coat,  as o c c u r r i n g i n the fawn b i r t h coat may be d i r e c t l y r e l a t e d to the need o f the fawn f o r b e t t e r i n s u l a t i o n i n i t s e a r l y stages. An a d u l t deer i n the summer appears need, and the undercoat  t o have no such  insulation  i s conspicuously l a c k i n g .  The c h a r a c t e r i s t i c i f l u f f y appearance of the newly born fawn can be a t t r i b u t e d t o g r e a t e r f o l l i c u l a r d e n s i t y which i s  185 subsequently reduced: by expansion of the s k i n a r e a without equivalent increase i n f o l l i c l e cle  elaboration.  The g r e a t e r  folli-  d e n s i t y r e s u l t i n g i n g r e a t e r h a i r c o n c e n t r a t i o n a l s o undoubt-  e d l y c o n t r i b u t e s to b e t t e r i n s u l a t i o n i n e a r l y stages of fawns life.  T h i s may  a l s o occur i n the newly born of other ungulates  but i s ;-str.l.kingly n o t i c e a b l e i n the b l a c k At f i r s t coat appeared  tail.  glance the w h i t e - t i p p e d h a i r s of the fawn b i r t h s i m i l a r to h e t e r o t y p e s ( h a i r s w i t h weak b a s a l end  but w e l l formed d i s t a l end) formed i n sheep. and diameter)  Morphometric  (length  study of h a i r samples r e v e a l e d no e s s e n t i a l morpho-  m e t r i c d i f f e r e n c e between these h a i r s and those o c c u r r i n g near them.  The d i f f e r e n c e s are only of c o l o u r a t i o n whose b a s i s l i e s  i n the b i o c h e m i s t r y of the h a i r f o l l i c l e s .  The d i f f e r e n c e of the  c o r t e x and the medulla have been r e f e r r e d to e a r l i e r . The h a i r types present on the body of the b l a c k t a i l resemble  those present on the  g e n e r a l form.  The beard type of h a i r s i n deer i s r e s t r i c t e d to  the t a i l and inguinum. of The  body of the goat; i n r e s p e c t of t h e i r  The l a r g e and the i n t e r m e d i a t e guard  hairs  deer are the kemp type and comparable t o kemps of the goat. s m a l l e s t of deer i n t e r m e d i a t e guard h a i r s , and those  constit-  u t i n g the bulk of the under coat i n fawn b i r t h coat, and are i n form s i m i l a r t o i n t e r m e d i a t e type h a i r s i n the goat. arising in first  The  hairs  formed s e c o n d a r i e s are a l s o of i n t e r m e d i a t e t y p e .  The w o o l l y under h a i r s c o n s t i t u t i n g the undercoat  of the deer are  comparable t o the w o o l l y undercoat h a i r s of the goat.  This i s  d i f f e r e n t from the h a i r types formed i n that i n sheap, the undercoat overtops the coarse outer coat h a i r s .  186 The g e n e r a l c h a r a c t e r i s t i c s o f pelage of non-woolly  animal  remains c o n s t a n t , although there may be some v a r i a t i o n i n d e t a i l w i t h changing seasons.  F i b r e s may v a r y g r e a t l y i n l e n g t h and  diameter but a l l grade i n t o one another from one extreme t o the other.  " U s u a l l y the c o a r s e r f i b r e s extend w e l l beyond the o t h e r s  and approximate  t o a l o o s e d e f i n i t i v e coat w h i l e the f i n e r  are c l o s e l y d i s p o s e d and suggest wo:o£ly/ undercoat". t i a l l y a l l the f i b r e s a r e of one type. category.  Cattle f a l l  fibres  Thus essenInto t h i s  In mouflon the undercoat reached the same l e n g t h as  the o v e r c o a t , whereas i n the case of goat the under wool was s h o r t e r than t h a t of mouflon and thus l i k e t h a t i n deer Ryder (1966). In deer no awns have been observed.  I t i s also  interesting  to r e c o l l e c t that F r i e n d & H e s s e l t o n ( 1 9 6 6 ) observed i n an Odocoileus v l r g l n i a n u s patches on the body where the w o o l l y under h a i r s had overtopped guard h a i r s which were not v i s i b l e  externally.  T h i s c o n d i t i o n of exposed wool has been r e p o r t e d as a r a r e anomaly. No doubt  i t i s g e n e t i c a l l y r e g u l a t e d and occurs as a mutant s t a t e .  I f one were t o t r a c e the development  of w o o l l y coat i n  ungulates s t u d i e s , c a t t l e would r e p r e s e n t the p r i m i t i v e  non-woolly  type; deer and goat r e p r e s e n t the p r i m i t i v e wooly type; the mouflon has a g r e a t e r development  of wool; next come domestic  sheep breeds, t e r m i n a t i n g i n the merino, which r e p r e s e n t s the w o o l l y c o a t a t i t s h i g h t e s t development  so f a r .  The c u t i c u l a r s c a l e c h a r a c t e r i s t i c s of the h a i r types a r e of i n t e r e s t w i t h i n a group such as the u n g u l a t e s ; these have been found t o depend on the p h y s i c a l dimensions of the h a i r and not on i t ' s m o r p h o l o g i c a l type (Mahal e t a l 1 9 5 1 ) .  Appleyard  (i960)  187 r e f e r s to s c a l e p a t t e r n s on h a i r s from genus Cervus and  states  t h a t c o a r s e h a i r s have a t t h e i r base an " i r r e g u l a r p e t a l "  scale  p a t t e r n , w h i l e a t mid-way and a t the t i p i t i s " i r r e g u l a r waved mosaic" w i t h 'smooth' margins and i n t e r m a r g i n a l d i s t a n c e •close'.  In the case of b l a c k t a i l  o n l y some of the very t h i c k  guard h a i r s bear " i r r e g u l a r p e t a l " s c a l e p a t t e r n on the base all  the o t h e r s bear  Appleyard's  (i960)  —  " i r r e g u l a r mosaic" t o " i r r e g u l a r waved mosaic" statement t h a t a l l f i n e h a i r s i n Cervus bear  fragmental medulla i s of i n t e r e s t , as i n the case of b l a c k t a i l the  f i n e w o o l l y under h a i r s a r e non-medullated.  They a l s o bear a  s c a l e p a t t e r n which resembles a v a r i a t i o n of the. c o r o n a l type as r e f e r r e d t o by Mahal et a l ( 1 9 5 1 ) r a t h e r than the i r r e g u l a r waved mosaic p a t t e r n as suggested by Appleyard ( i 9 6 0 ) .  I f one  i s to  take i n t o account the b l a c k t a i l h a i r s c a l e morphology i n comparison with c a t t l e , resemble  sheep.  sheep and goat, then b l a c k t a i l can be s a i d t o " R i p p l e d c r e n a t e " s c a l e margins present i n  r e g i o n s of c a t t l e and goat haifis were a t no time observed on b l a c k tail  hairs. The narrowing of the l a t t i c e d medulla i n the base of the  guard h a i r s i n deer i s more abrupt than t h a t i n the sheep. branched h a i r f i b r e s of the type r e f e r r e d by Ryder  (i960,  Also 1966)  as o c c u r r i n g i n the mouflon and the goat have not been observed i n Odocoileus. A d u l t Odocoileus have two d i s t i n c t  s e a s o n a l pelages and these  r e p l a c e each other a l t e r n a t e l y a c c o r d i n g to the season.  These  c o a t s d i f f e r from each other i n r e s p e c t of h a i r dimensions and colouration.  The summer coat h a i r s are l o n g e r , more s l e n d e r and  i n g e n e r a l the pelage p r e s e n t s a r e d d i s h - y e l l o w appearance.  The  188 w i n t e r coat h a i r s on the other hand p r e s e n t s an o v e r a l l g r e y i s h appearance; have l a r g e r diameter, and more crimped nature of the hair shaft.  The summer coat h a i r s  (intermediate guard h a i r s )  presented no d i s t i n c t i v e l e n g t h to diameter r e l a t i o n s h i p p a t t e r n whereas h a i r growing from the same f o l l i c l e s  i n w i n t e r have had a  d i s t i n c t i v e c o r r e l a t i o n between l e n g t h and diameter i . e . i n c r e a s i n g length.  The w i n t e r coat i s a l s o c h a r a c t e r i z e d by p o s s e s s i o n of  w o o l l y undercoat — a r i s i n g i n secondary f o l l i c l e s .  T h i s i s absent  i n the summer c o a t . These changes  i n h a i r c o l o u r a t i o n and morphology  are of  p a r t i c u l a r s i g n i f i c a n c e because the same f o l l i c l e s produce these two types of h a i r s .  The changing a c t i v i t y p a t t e r n of the melano-  c y t e s , and the v a r i a t i o n s i n b i o c h e m i c a l r e a c t i o n s i n v o l v e d produ c i n g melanin, pheomelanin to are of  study.  e t c . , would be of p a r t i c u l a r  interest  The f o l l i c l e s producing ' w h i t e - t i p p e d ' h a i r s i n fawn  a l s o of i n t e r e s t as i t i s obvious t h a t d u r i n g the f o r m a t i o n the white t i p the melanocytes a r e behaving v e r y d i f f e r e n t l y .  B i l l i n g h a m and S i l v e r s  ( i 9 6 0 )  suggest t h a t white c o l o u r i n g or  " s p o t t i n g " may be due t o a g e n e t i c b a r r i e r p r e v e n t i n g melanocytes from r e a c h i n g t h e i r end organ from the n e u r a l c r e s t or a t l e a s t f a i l i n g to d i f f e r e n t i a t e .  The f o l l i c l e s  producing w h i t e - t i p p e d  h a i r s however o f t e n show a brownish p i g m e n t a t i o n .  Perhaps t h i s i s  because the white t i p has a l r e a d y been formed, and the r e s t of the  h a i r body which i s pigmented  i s i n the process of f o r m a t i o n .  Such sharp changes o f c o l o u r a t i o n have not been r e f e r r e d t o i n goat, mouflon, domestic sheep, or i n c a t t l e . The l e n g t h and diameter v a r i a t i o n i n summer h a i r s produced by the same f o l l i c l e i s a l s o o f great i n t e r e s t , and r e f l e c t s  189 f u n c t i o n a l p l a s t i c i t y on the p a r t of the h a i r f o l l i c l e s .  The  environmental c o n d i t i o n s may a l s o have a b e a r i n g on these n o r m a l l y o c c u r r i n g changes.  The h a i r l e n g t h can,be v a r i e d e i t h e r by  i n c r e a s e d r a t e o f growth, or l o n g e r p e r i o d o f growth.  In deer  the former appears l i k e l y as no n o t i c e a b l e change i n the d u r a t i o n of h a i r growth was d e t e c t e d i n the present study.  Use of auto-  r a d i o g r a p h i c techniques may h e l p t o e l u c i d a t e t h i s i s s u e . major f a c t o r r e s p o n s i b l e f o r the changes i n h a i r diameter  The i s the  medulla, but the processes governing i t s f o r m a t i o n a r e not c l e a r . T h i s must v a r y i n d i f f e r e n t body r e g i o n s o f the same coat too, f o r i n a d u l t s the abdominal h a i r s have a much l a r g e r development of the medulla. Adaptive v a l u e The major f u n c t i o n performed  by Odocolleus pelage i s i n  a d a p t i n g the animal t o i t s environment  and a c t i v i t i e s w i t h i n the  pelage l i k e the h a i r growth c y c l e s and the t i m i n g of moult a r e o r i e n t e d towards meeting  the above mentioned o b j e c t i v e .  w i n t e r coat has f e a t u r e s adapted capacity.  The deer  t o i n c r e a s e the i n s u l a t i o n  These a r e , p r o d u c t i o n s of h e a v i l y medullated h a i r s , and  the presence  of a w e l l developed w o o l l y undercoat.  The c r i n k y  nature of the i n t e r m e d i a t e guard h a i r s i s h e l p f u l f o r proper accommodation of the w o o l l y undercoat.  The g r e a t e r v a r i a t i o n i n  the l e n g t h of i n d i v i d u a l w i n t e r coat guard h a i r s , enables them t o be arranged compactly  and thus p r o v i d e b e t t e r i n s u l a t i o n .  The  s i g n i f i c a n c e o f the medulla i n deer i n s u l a t i o n i s f u r t h e r a t t e s t e d by the f a c t t h a t the Southern C a l i f o r n i a n forms l i v i n g i n dry a r i d c o n d i t i o n s have i n t h e i r winter coat h a i r s much l e s s p r o p o r t i o n  190 of medulla,  ( r e s u l t i n g i n s m a l l e r h a i r diameter)  than n o t i c e d i n  the i d e n t i c a l r e g i o n of the Alaskan forms l i v i n g under very c o l d winter c o n d i t i o n s .  The absence of w o o l l y undercoat  i n summer and  the l o n g e r h a i r s makes summer c o a t o f t e n , more amenable to a i r c i r c u l a t i o n , and thus w e l l s u i t e d f o r warm summer c o n d i t i o n s . As a f u r t h e r a d a p t a t i o n t o thermoregulation, the pinnae of deer  i n h e i g h t o f summer appears  of s m a l l h a i r s .  naked and s h a r i n g a sparse "down"  I d i d not determine  whether or not there was a  seasonal r e d u c t i o n i n the number o f f o l l i c l e s producing however t h i s seems p r o b a b l e . and  i t i s tempting  hairs,  The blood supply here i s profuse  t o suggest t h a t t h i s may have some thermoregu-  l a t o r y f u n c t i o n i n the deer. P r o d u c t i o n of a w o o l l y undercoat which c e r v i d s have adapted Przewalskium  i s not the o n l y way i n  to winter c o n d i t i o n s .  The sub genus  a c e r v i n e form i n h a b i t i n g c o l d T i b e t a n h i g h l a n d s has  i n i t s w i n t e r coat no w o o l l y undercoat  (Flerov i 9 6 0 ) .  Instead  i t ' s winter coat c o n s i s t s of t h i c k h e a v i l y medullated h a i r s . T h i s supports the c o n t e n t i o n that i n deer h a i r medulla importance  i n s e c u r i n g adequate i n s u l a t i o n .  i s of g r e a t  I t would be of g r e a t  i n t e r e s t t o examine t h i s coat h i s t o l o g i c a l l y as w e l l as t o compare i n s u l a t i o n c a p a c i t y of t h i s type of coat w i t h t h a t where a woolly undercoat  i s also present.  Woolly undercoat  i s present i n goats and mouflon and i s  dominant i n the domestic i n cold conditions.  sheep, and p r o v i d e s e f f e c t i v e  insulation  I n c a t t l e however the s i t u a t i o n i s d i f f e r e n t .  Dowling (1959) has concluded t h a t here the summer h a i r s a r e s h o r t e r than w i n t e r h a i r s and possess g r e a t e r m e d u l l a t i o n and h a i r diameter.  The w i n t e r coat f i b r e s a r e on the other hand long and  191 non-medullated.  Dowling  f u r t h e r contends  that  -thicker shorter  medullated f i b r e s which a r e s t i f f e r enhance a i r movement a t the skin surface.  T h i s would p r o v i d e a g r e a t e r o p p o r t u n i t y f o r  e v a p o r a t i o n of m o i s t u r e .  F u r t h e r the more medullated the f i b r e  the more e f f e c t i v e would be the r e f l e c t i o n of the i n f r a r e d wave lengths of solar r a d i a t i o n .  He a l s o found on experimentation  t h a t animals w i t h medullated coat were more h e a t - t o l e r a n t than those having h a i r s without or w i t h s m a l l medulla.  I n Odocolleus  the mechanism i s o b v i o u s l y d i f f e r e n t and heavy m e d u l l a t i o n f a c i l itates better insulation.  Apparently i n c a t t l e the winter  insu-  l a t i o n i s a f f e c t e d o n l y by h a v i n g a longer coat, which may p r o v i d e b e t t e r body coverage.  L i k e deer i n c a t t l e too t h e r e i s g r e a t e r  v a r i a t i o n i n h a i r l e n g t h o f w i n t e r coat h a i r s . Moult In deer the summer and w i n t e r coats a r e assumed by the animal through a process of moulting,  j u s t before the onset of the  summer and w i n t e r seasons r e s p e c t i v e l y . moults  Thus the deer overcoat  twice namely i n s p r i n g , and l a t e summer t o e a r l y autumn,  and the w o o l l y undercoat moults o n l y once a year namely i n s p r i n g . The primary and l a t e r formed secondary f o l l i c l e s thus have d i f f e r ent c y c l e s .  The goat has c o m p a r a t i v e l y a very p r i m i t i v e  cycle.  Here both primary and secondary f o l l i c l e s undergo a s i m i l a r i.e  of a c t i v i t y i n summer and i n a c t i v i t y i n w i n t e r .  goat l a c k s w o o l l y undercoat.  cycle  I n summer the  I n mouflon both the primary and  secondary f o l l i c l e s a r e shed i n s p r i n g , and the pelage i s devoid of w o o l l y undercoat  i n summer.  Some p r i m a r i e s a r e a l s o shed a g a i n  i n autumn, but t h e r e i s no moult as such.  T h i s i s homologous t o  192 deer autumn moult.  T h i s i s a l s o t r u e of p r i m i t i v e domestic  sheep  and to a l e s s e r extent i n the more h i g h l y evolved domestic  sheep.  In c a t t l e , although some h a i r s are c o n s t a n t l y being shed a l l the year around (very much u n l i k e d e e r ) , two d i s t i n c t p e r i o d s have been observed overcoat and undercoat I n Odocoileus directions.  namely i n s p r i n g and  shedding  the autumn.  The  are shed and r e p l a c e d twice a y e a r .  s p r i n g and autumn moults have d i f f e r e n t  The autumn moult i s caudad w h i l e the s p r i n g moult  begins on the f l a n k s and proceeds both cephalad and caudad. fawn b i r t h coat the moult i s caudad. i t are not known.  The  The  In  factors responsible for  extent to which the f o r m a t i o n of new  a c t s as a p h y s i o l o g i c a l or p h y s i c a l stimulus i n shedding  hair  of the  o l d h a i r i s a l s o of i n t e r e s t , i n i n v e s t i g a t i n g moult p a t t e r n s . I t would a l s o be of great s i g n i f i c a n c e to f i n d out i f there i s any phase d i f f e r e n c e i n a c t i v i t y of h a i r f o l l i c l e s over  different  r e g i o n s of the body and the e f f e c t of any t h a t t h i s has on the t i m i n g and the d i r e c t i o n of the moult.  L i n g (1965) has  rightly  s t r e s s e d the need to i n v e s t i g a t e these a s p e c t s . The d i r e c t i o n of moult i n the deer fawn has been d i s c u s s e d earlier.  No corresponding  Ryder ( i 9 6 0 ) has s t a t e d t h a t the  ones of goat and c a t t l e . coat of the mouflon was Here the shedding  o b s e r v a t i o n s are a v a i l a b l e on young  shed between f o u r and  began ( i n U.K.)  i n August.  i n mats of outer h a i r mixed w i t h wool. coming i n .  During September there was  the shoulder, and  t h i s was  b i r t h coat however tended new  h a i r coat and was  soon l o s t .  s i x months of The  The new  coat was  coat was  birth age. peeling  already  b i r t h coat remaining  on  Masses of wool from the  to remain a t t a c h e d to the t i p s of the  l o s t when the new  coat was  shed the f o l l o w -  1 9 3  ing  spring.  I n Odocoileus fawn moult takes l o n g e r than i n the  mouflon lamb, and there was no masses o f undercoat l e f t behind. In  mouflon a d u l t Ryder  ( i 9 6 0 ) , the t r e n d i s v e n t r a d .  The s p r i n g  moult begins from the a n t e r i o r and v e n t r a l p a r t s and the l o i n s are  l a s t t o moult.  There i s no autumn moult as such but o n l y  p a r t i a l shedding o f overcoat h a i r s . In  most of the domestic sheep even the s p r i n g moult has no  d i r e c t i o n as such but c o n s i s t s of o v e r h a i r and w o o l l y masses peeling o f f .  Though the wool i s dominant  i n the c o a t , kempts have  been observed t o have a p a r t i a l shedding i n autumn. horn sheep however S l e e  In W i l t s h i r e  (1959) r e p o r t s a s p r i n g moult p a t t e r n very  s i m i l a r t o that of the mouflon.  The domestic sheep a t times have  a tendency t o shed t h e i r h a i r s b e f o r e the new h a i r s , have emerged on the s u r f a c e ; g i v i n g r i s e t o occurence of b a l d patches on the body.  T h i s never occurs i n mouflon, goat, c a t t l e and O d o c o i l e u s . In  c a t t l e approximately f o u r months a r e r e q u i r e d t o complete  moult from w i n t e r to summer coat but the change over from summer to  w i n t e r r e q u i r e s l e s s time.  In deer the d u r a t i o n of the moult  as w e l l as time r e q u i r e d t o complete growth i s same f o r both coats. for  But summer coat i s borne on the deer body i n r e s t i n g stage  two months as a g a i n s t f i v e months f o r the r e s t i n g w i n t e r c o a t .  The p r o g r e s s of moult has not been r e c o r d e d i n f u l l d e t a i l f o r cattle.  Hayman and Nay (i960) r e p o r t t h a t the new summer coat  f i r s t appears on the neck and the-back of t h i g h s and g r a d u a l l y extends i n a r e a over the shoulders and the back. the  In Bos taurus  mid s i d e i s the l a s t t o moult, i n t o the summer c o a t .  In Bos  i n d i c u s however the back and the rump a r e the l a s t t o moult the  summer c o a t .  into  No d e f i n i t e moult p a t t e r n has been r e c o r d e d f o r  1  change over the summer to winter Cowan ( 1 9 5 6 )  ex-  coat.  s t a t e s t h a t i n the b l a c k t a i l males normally  moult a month ahead of the female w i t h young.  The  female without  fawns are s a i d to moult the same time as the males. moulting of does w i t h fawns i s very l i k e l y due demands of l a c t a t i o n . known to d e l a y moulting  The d e l a y i n  to the a d d i t i o n a l  N u t r i t i o n a l and d i s e a s e s t r e s s has been i n animals and t h e r e f o r e the  likelihood  t h a t s t r e s s of r a i s i n g fawns b r i n g s about a d e l a y i n moulting seems r e a s o n a b l e .  In mammals having a delayed i m p l a n t a t i o n there  i s g e n e r a l l y a r e l a t i o n s h i p betvreen i m p l a n t a t i o n of the b l a s t o c y s t and m o u l t i n g . of  In deer however o e s t r u s occurs i n the l a t t e r p a r t  the autumn moult and the i m p l a n t a t i o n a month l a t e r , the young  being born when the s p r i n g moult i s complete. In c a t t l e , to  sheep, goat, the pelage has not been r e c o r d e d  be of any b e h a v i o u r a l s i g n i f i c a n c e .  t i o n ; Cowan and G e i s t ( 1 9 6 1 ) Odocoileus same was  Odocoileus  i s an excep-  r e p o r t t h a t when i n a g r e s s i v e s t a t e  e l e v a t e s i t s pelage as p a r t of a t h r e a t d i s p l a y .  The  r e p o r t e d by G i e s t f o r the d o r s a l r i d g e h a i r s of Oreamnus  display. E f f e c t of adverse  nutrition  Adverse n u t r i t i o n was on the b l a c k t a i l pelage.  observed  to have s i g n i f i c a n t  In e x p e r i m e n t a l l y s t a r v e d b l a c k  the l a r g e guard h a i r s were l o s t but no g e n e r a l premature of  the coat o c c u r r e d .  The  effect tail  shedding  experimental animals d i d e x h b i t  tendency to chew o f f h a i r s from f l a n k s exposing bare patches the s i d e s and the pelage.  on  c o n s i d e r a b l y a f f e c t i n g the i n s u l a t i o n c a p a c i t y of I t appears however u n l i k e l y t h a t i n the w i l d where  195 roughage i s a v a i l a b l e i n q u a n t i t y , i f not i n q u a l i t y , such off  w i l l take p l a c e .  chewing  The h a i r s borne by underfed animals were of  s m a l l e r dimensions and had p r o p o r t i o n a t e l y b e t t e r developed c o r t e x , which made them s l i g h t l y s t i f f .  S t a t i s t i c a l a n a l y s i s of  data c o l l e c t e d on h a i r l e n g t h and diameter from underfed animals and i t s subsequent r e g r e s s i o n a n a l y s i s i n d i c a t e d t h a t i n the unde r f e d animals though the a c t u a l l e n g t h and diameter was  less,  r e l a t i v e i n c r e a s e i n diameter f o r any u n i t of h a i r l e n g t h g r e a t e r than t h a t found i n w e l l f e d a n i m a l s  1  hairs.  the  was  Thus when the  n u t r i e n t s are l i m i t e d the growth i n h a i r diameter enjoys a p r i o r i t y over growth i n l e n g t h .  H a i r diameter i s p r i m a r i l y determined  by the extent of the medulla and i t s presence a l s o h e l p s i n providing insulation.  T h i s can be i n t e r p r e t e d i n support of im-  portance of the medulla i n p r o v i d i n g adequate d i e t i s a l s o supposed fibres. In  insulation.  to reduce the b r e a k i n g s t r e n g t h of h a i r  A t e s t on deer f i b r e s however proved course of an a r t i f i c i a l l y  inconclusive.  induced h a i r c y c l e , the pro-  cess of f o l l i c l e r e g e n e r a t i o n and p r o d u c t i o n of new s i d e r a b l y slower than t h a t i n w e l l f e d a n i m a l s . moulting was In  A poor  h a i r i s con-  No d e l a y i n  observed i n the experimental b l a c k t a i l deer.  the b l a c k t a i l the r a t e of h a i r growth was much f a s t e r  around b i o p s y sampling s i t e s , than t h a t i n a d j o i n i n g a r e a .  This  has been observed i n other s p e c i e s and has been e x p l a i n e d as a consequence  of i n c r e a s e d m i t o t i c a c t i v i t y c h a r a c t e r i s t i c of areas  w i t h h e a l i n g wounds Montagna ( 1 9 5 6 ) .  However i t has not been  r e c o r d e d i n sheep and c a t t l e , where s k i n b i o p s i e s a r e o f t e n taken. In to  c a t t l e , Hayman and Nay  p r o l o n g s p r i n g shedding.  ( i 9 6 0 ) n u t r i t i o n a l s t r e s s i s known  A l s o the p r o p o r t i o n of p a r t i a l l y  196 medullated h a i r s i n the w i n t e r coat i n c r e a s e d .  In undernourished  animals the w i n t e r coat had developed more r a p i d l y , grew longer and was fed  r e t a i n e d l a t e on i n t o the s p r i n g , than i n case of w e l l  animals.  T h i s i s i n c o n t r a s t to deer.  The guard  hair  diameter a l s o appears to be reduced i n underfed a n i m a l s . shedding due to adverse n u t r i t i o n was In  No  hair  noticed.  sheep adverse n u t r i t i o n produced no h a i r shedding.  A  decrease i n h a i r l e n g t h was more e v i d e n t than decrease i n diameter. In deer both were e v i d e n t .  A poor d i e t a l s o reduces b r e a k i n g  s t r e n g t h of the h a i r f i b r e i n sheep.  No comparable data are  a v a i l a b l e f o r the goat. In  c o n c l u s i o n i t can be s a i d t h a t the present study has  r e v e a l e d a number of f e a t u r e s of the c e r v i d p i l a r y system which was  h i t h e r t o an obscure and r e l a t i v e l y unknown e n t i t y .  The  e m b r y o l o g i c a l development of the f o l l i c l e s has been s t u d i e s and the presence of t y l o t r i c h - l i k e f o l l i c l e s d e f i n i t i v e l y  established/  A m o r p h o l o g i c a l study of the pelage types and the h a i r s c o n s t i t u t e them has been made and has r e v e a l e d the  that  remarkable  morphometric and pigment d i f f e r e n c e s i n h a i r s produced by the same follicles  d u r i n g the course of a year, and a l s o i n d i f f e r e n t  age-  r e l a t e d pelages.  The dynamics of the pelage i . e h a i r c y c l e s and  p a t t e r n s of moult  i n the course of a year have a l s o been s t u d i e d .  The main f u n c t i o n of c e r v i d pelage i s assumed to be t o adapt animal to i t s environment, insulation.  i n p a r t i c u l a r by p r o v i d i n g  the  adequate  In c o n t r a s t t o t h e c a t t l e t h i s has been done i n deer  by the presence of a w e l l developed medulla as w e l l as a undercoat i n winter pelage.  woolly  The deer summer coat has i n c o n t r a s t  no w o o l l y undercoat and much s m a l l e r medulla development.  197 Adverse n u t r i t i o n has been n o t i c e d to reduce deer h a i r l e n g t h , and diameter, as w e l l as the c a p a c i t y of the animal t o regrow h a i r s on plucked s i t e s .  However f o r a u n i t i n c r e a s e i n l e n g t h , the  r e l a t i v e i n c r e a s e of h a i r diameter was than i n w e l l f e d a n i m a l s .  g r e a t e r i n underfed animals  Thus even under s t r e s s emphasis i s put  on diameter i n c r e a s e ( i . e . i n c r e a s e d medulla l e a d i n g to r e l a t i v e l y g r e a t e r i n s u l a t i o n ) than on l e n g t h may  be  significant.  T h i s study has r e v e a l e d few c h a r a c t e r i s t i c s of the f o l l i c l e s , h a i r , or pelage t h a t can be regarded as of systematic cance.  signifi-  The two annual moults, the presence of the second  glassy  l a y e r , the sinuous r a t h e r than t i g h t c o i l e d sweat g l a n d and a l l are  d e s c r i b e d only from deer and may  cervidae.  be c h a r a c t e r i s t i c of the  However w i t h only one s p e c i e s s t u d i e d i n that  t h i s cannot be  detail  certain.  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Seasonal changes i n coat c h a r a c t e r and t h e i r importance i n heat regulation. A u s t r a l i a n J . A g r l • Res. 6: 891-902. 1957. P h o t o p e r i o d i c i t y i n c a t t l e . I I . The e q u a t o r i a l l i g h t environment and i t s e f f e c t on the coat of European c a t t l e . A u s t r a l i a n J . A g r i c . Res. 8: 733-739.  APPENDIX  I  WEEKLY WEIGHT DATA Date Aug 6 6 Sept. 6 6 Sept. 6 6 Sept. 6 6 Sept. 6 6 1 s t Oct. 6 6 8 Oct. 6 6 1 5 Oct. 6 6 2 2 Oct. 6 6 2 9 Oct. 6 6 5 Nov. 6 6 1 2 Nov. 6 6 2 6 Nov. 6 6 2 Dec. 6 6 1 0 Dec. 6 6 1 7 Dec. 6 6 24 Dec. 6 6 2 7  3rd 9th 17 24  7  14 2 2 2 7  4 18 2 5  4 12 18 25 18 8 15 22 29 6 t h 1 3  18  10 1st 8 15  Jan. 6 7 Jan. 6 7 Jan. 6 7 Jan. 6 7 Feb. 6 7 Feb. 6 7 Feb. 6 7 March 6 7 March 6 7 March 6 7 March 6 7 April 6 7 April 6 7 April 6 7 April 6 7 April 6 7 May 6 7 May 6 7 May 6 7 June 6 7 July 6 7 July 6 7 July 6 7  Ul6 194 199 190.5 194 192 193 190 186  183 176  172  164 155 154 154  147 142  TR  U26  w4  160 160 161 160 160 160  184 191 192 192 201 201 202  127 132  160 162 160  156 i4o  -  -  128  -  128  143 146  128  147 147 148 148 147  -  146  150 151  152 154 154 156  158 158 159 159 159 155  158 158 157  -  — —  125 126 —  -  125 125 126 125 127 127 127  -  127 123 125  122 122  207  202 200 195 192 195 185 182 179 176  138 138 14 0 140 142 145 144  146 142 138 142 126 124 120 121  176 175  121 121 121  173 170  121 124  176 174 160 160 166 166 166  164 164 160 168  168 168 170 170  171 176 178 177  123 126 126  128 128 130  131  132 132 134 134 134 137  139 142 147 148 153  208 APPENDIX I I FEED INTAKE IN CALORIES (WEEKLY AVERAGE) Date  1966  Aug. to Sept.  2 6  Sept. to Sept.  2  Ul6  Tg  U26  W4  4685.20  4673.13  7124.11  6527.26  4609.71  4571.54  5828.82  5803.73  4317.64  3644.59  6108.16  5633.73  3 9 4 9 . 3 7  3809.68  13803.15  5117.67  Sept. 2 2 to Sept. 28  3149.33  3111.24  5841.52  5584.27  Sept. to Oct.  2565.I8  2641.38  5193.87  5295.46  2742.97  6285.98  5H7.67  5740.24  2146.11  2209.61  4139.85  4876.46  2031.82  2044.52  2806.4  4876.39  1968.33  3 9 3 . 6 6  2349.30  4762.10  2323.89  914.03  2781.06  5041.48  2311.21  177.78  2946.15  4089.06  Sept. to Sept. Sept. to Sept.  Oct. to Oct. Oct. to Oct. Oct. to Oct.;? Oct. to Nov. Nov. to Nov. Nov. to Nov.  1  8 9  1 5 1 6  2 1  2 9  5 6  1 2  1 3  1 9 2 0  2 6  2 7  2  3  9 1 0  1 6  209 APPENDIX I I  (cont'd)  FEED INTAKE IN CALORIES (WEEKLY AVERAGE) Date 1966  Ul6  TR  U26  w4  .  Nov....17 to Nov. 22  2311.21  179.0  2844.69  4000.17  Nov. 23 to Nov. 29  2514.41  747.96  3212.83  4317.64  Nov. 30 to Dec. 6  3136.64  1981.09  3581.10  5651.03  Dee. 7 to Dec. 13  5592.92  2539.78  3873.17  5270.05  Dec. 14 to Dec. 20  2869.96  2435.20  3365.21  5790.72  Dec. 21 to Dec. 27  4038.26  3060.44  3708.09  5689.12  Dec. 28 to Jan. 3  5765.32  2488.99  3657.29  6222.49  5562.14  2857.26  4228.75  5857.17  Jan. 11 to Jan. 17  5790.72  2374.71  3898.57  3644.69  Jan. 18 to Jan. 24  5041.48  2958.85  4470.03  5065.29  Jan. 25 to Jan. 31  4876.39  2412.79  4863.69  4330.34  Feb. to Feb.  5854.22  2285.80  4063.57  3923.79  1967 Jan. 4 to Jan. 10  1 7  210 APPENDIX I I  (cont»d)  FEED INTAKE IN CALORIES (WEEKLY AVERAGE) Date 1967  U16  TR  U26  Feb. 8 to Feb. 14  5346.34  2376.69  4063.57  3949.37  5155.77  3123.93  4076.36  4216.05  Feb. 22 to Feb. 28  5562.14  2463.59  4076.36  4266.84  March to March  5866.92  2552.48  3822.38  4177.95  5460.55  2679.47  4216.05  4622.41  March 15 to March 21  5689.44  2946.15  3736.49  3949.30  March 22 to March 28  5816412  3238.74  3784.28  4139.89  March 29 to April 4  5358.95  2933.46  3467.38  4558.92  5155.77  2933.46  3923.97  4203.35  5033.38  2984.25  4127.15  4367.17  4749.70  3085.84  3923.97  4203.35  4495.42  3009.65  3911.27  4139.85  Feb. 15 to Feb. 21  1 7  March 8 to March 14  April 5 to A p r i l 11 A p r i l 12 to A p r i l 18 A p r i l 19 to A p r i l 25 A p r i l 26 to May 2  w4  211"  APPENDIX I I (cont»d) FEED INTAKE IN CALORIES (WEEKLY AVERAGE) V  Date 1 9 6 7  W4  TR  U26  4292.24  2933.46  3809.08  4139.86  4089.06  2933.46  3708.08  4812.90  3987.47  2831.92  3835.08  4089.05  3911.28  2755.67  4038.26  3987.47  3987.47  2755.67  4419.23  4660.57  June 7 to June 13  3962.07  2986.25  6381.13  4647.81  June 14 to June 20  4089.06  2933.46  3923.97  4419.23  June 21 to June 27  4089.06  2933.46  3923.97  4419.23  June 28 to 4 July  4089.06  2984.25  4774.80  4431.93  July 5 to 11 July  4089.06  2933.46  4863.69  5041.48  12 July to 18 July  4089.06  2933.46  4749.40  4914.49  July 19 to July 25  4089.06  2933.46  5295.46  5295.46  4089.06  2933-46  5126.14  5052.06  May May May May May May May  to  to  to  to  3 9 10 16 17 23 24  May  30  May  31  to June  6  26 July to July 31  Ul6  212 APPENDIX I I I HISTOLOGICAL TREATMENT S k i n biopsy  samples taken by means of a t r e p h i n e were  f i x e d i n Bouin"s f l u i d f o r 24 hours and a l c o h o l f o r storage. f i x e d and  preserved  The  t r a n s f e r r e d to  f o e t a l m a t e r i a l a v a i l a b l e was  i n formol  already  saline.  Subsequently the f i x e d m a t e r i a l was Where h a i r s were present  70%  t r e a t e d as f o l l o w s .  they were cut by means of  fine  s u r g i c a l s c i s s o r s as c l o s e to the s k i n s u r f a c e as p o s s i b l e , t a k i n g care to l e a v e enough l e n g t h to adequately i n d i c a t e the h a i r o r i e n t a t i o n v i s a v i s the s k i n s u r f a c e .  Using a sharp  s i n g l e edge ("Gem") s a f e t y r a z e r blade and a d i s s e c t i n g microscope the t i s s u e m a t e r i a l was the h a i r s .  halved  i n t o two  As f a r as p o s s i b l e attempt was  f o l l i c l e s along dehydrated and  t h e i r whole l e n g t h .  The  c l e a r e d i n a T i s s u e Tek  along the plane of  made to cut the h a i r  m a t e r i a l so:out  was  Automatic t i s s u e p r o c e s s i n g  machine, u s i n g the f o l l o w i n g r o u t i n e : W-AX  EMBEDDING  10% F o r m a l i n 70% A l c o h o l ( i ) 70% A l c o h o l ( i i ) 90% A l c o h o l ( i ) 90% A l c o h o l ( i i ) Absolute A l c o h o l ( i ) Absolute A l c o h o l ( i i ) Absolute A l c o h o l ( i i i ) Xylene or Chloroform ( i ) Xylene or Chloroform ( i i ) Wax ( i ) Wax + 5% Bees wax ( i i )  SKIN Foetal Storage 24 h r s . 4 hrs. 2 hrs. 2 hrs. 1 hr. 1 hr. 1 hr. 1V2 hrs. l l / 2 hrs. 2 hrs. 2 hrs. 18 h r s .  SKIN Adult Storage 24 h r s . 4 hrs. 2 hrs. 2 hrs. 1 hr. 1 hr. 1 hr. 1V2 hrs. l V 2 hrs. hrs. hrs. 2.2 "hrs. 4  4  213 Of the two with  p o r t i o n s of each sample,, one was  embedded i n  wax  i t s l o n g i t u d i n a l l y cut surface f a c i n g the base of the mould,  while  i n case of the other h a l f i t was  f a c i n g the mould base.  The  the s k i n s u r f a c e which  b l o c k s were duly l a b e l l e d .  was  On  s e c t i o n i n g , the former gave l o n g i t u d i n a l s e c t i o n of the h a i r f o l l i c l e s while 8 to 10/*and  the l a t t e r gave s u r f a c e  (Transverse  sectioni).  t h i c k s e c t i o n s were cut on a r o t a r y microtome, mounted,  s t a i n e d as f o l l o w s u s i n g the f o l l o w i n g methods. a) Haematoxylin and b) M a l l o r y ' s t r i p l e (Cason, J.E., c) V e r h o e f f ' s  and  eosin s t a i n : a r a p i d one 1950.  Van  step method.  S t a i n Technology, 2j>:  Giesons method.  Gurr  p.  (1952)  S k i n samples were a l s o taken from tanned deer h i d e s coat and winter The  samples were, p l a c e d i n a 0.5$  cedarwooxl o i l and  embedded i n 5 6  s e c t i o n e d a t 8/*- to 10/*' eosin.  (Summer  coat) and were t r e a t e d as f o l l o w s : s o l u t i o n of  trisodium  phosphate f o r three days, dehydrated v i a a l c o h o l and  and  225)  and  0  M. P t . wax.  The  cleared i n  blocks were  s e c t i o n s s t a i n e d with Haematoxylin  APPENDIX IV KEY Ap Bf CR" CO Cp Cts Cap CIGF D Dp Dil.p. DDC E ES F FB FF FS Fib FBS Fan GF GM Gr H HC He" HN Hu HF Hcu IS IGH ISC Int.Ca LP LS Lu LGH LGHF LIGF M Mec Mel NH  TO ABBREVIATIONS USED IN ILLUSTRATIONS A r r e c t o r p i l i i muscle Branching f o l l i c l e s Club h a i r Cortex C e n t r a l primary f o l l i c l e Connective t i s s u e sheath Capsule C e n t r a l i n t e r m e d i a t e guard hair f o l l i c l e Dermis Dermal p a p i l l a Dilated portion Dedifferentiated c e l l s Epidermis Ental swelling Fibrocytes F o l l i c l e bulb F o l l i c l e folds F i r s t formed secondary f o l l i c l e Fibres F o l l i c l e base F o l l i c l e anlagen Growing f o l l i c l e G l a s s y membrane C e l l s c o n t a i n i n g 'Keratohyaline granules Keratinized hair Hair canal Henle s layer H a i r cone Huxley s layer Hair f o l l i c l e Hair c u t i c l e I n t e r n a l r o o t sheath Intermediate guard h a i r s I n t e r n a l r o o t sheath c u t i c l e Intracellular cavities L a t e r a l primary f o l l i c l e s L a t e r formed secondary f o l l i c l e Lumen Large guard h a i r s Large guard h a i r f o l l i c l e L a t e r a l i n t e r m e d i a t e guard h a i r follicles Medulla Mesenchymal c e l l s Melanocytes New h a i r 1  1  215 APPENDIX IV (cont'd)  OS p PP PP PLF SbC SbG SC SGe SGr Sb 0 SSP SWD SWG SW 0 T Tr UDC WtpF WtP WuH  Outer sheath ( E x t e r n a l r o o t sheath) Periderm Paired f o l l i c l e s Pre p a p i l l a Plucked f o l l i c l e Sebaceous c e l l s Sebaceous gland Stratum corneum Stratum germinativum Stratum granulosum Sebaceous gland opening Stratum spinosum Sweat duct Sweat gland Sweat gland opening T r i o grouping' Transitional hair Undifferentiated c e l l s White t i p p e d h a i r f o l l i c l e s White t i p p e d h a i r Woolly under h a i r  

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