Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Desmids of some lakes in southwestern British Columbia with observations on Triploceras in culture Gerrath, Joseph Frederick 1965

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1965_A6_7 G4.pdf [ 6.58MB ]
Metadata
JSON: 831-1.0105285.json
JSON-LD: 831-1.0105285-ld.json
RDF/XML (Pretty): 831-1.0105285-rdf.xml
RDF/JSON: 831-1.0105285-rdf.json
Turtle: 831-1.0105285-turtle.txt
N-Triples: 831-1.0105285-rdf-ntriples.txt
Original Record: 831-1.0105285-source.json
Full Text
831-1.0105285-fulltext.txt
Citation
831-1.0105285.ris

Full Text

DESMIDS OF SOME LAKES IN SOUTHWESTERN BRITISH COLUMBIA WITH OBSERVATIONS ON TRIPLOCERAS IN CULTURE 4 by JOSEPH FREDRICK GERRATH B.A., University of British Columbia, 1959 B.Sc., University of British Columbia, 1963 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of BIOLOGY AND BOTANY We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA August 1965 In presenting th i s thes i s in p a r t i a l f u l f i lmen t of the requirements for an advanced degree at the Un ivers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make i t f r ee l y a va i l ab l e fo r reference and study. I fur ther agree that per -mission for extensive copying of t h i s thes i s for scho la r l y purposes may be granted by the Head of my Department or by his representatives,, It is understood that copying or p u b l i -ca t ion of th i s thes i s for f i n anc i a l gain sha l l not be allowed without my wr i t ten permiss ion. Department The Un ivers i ty of B r i t i s h Columbia Vancouver 8, Canada Date /' £ ^J<^fuZ. / 9&S~ i ABSTRACT A l g a l c o l l e c t i o n s from e i g h t lakes i n southwestern B r i -t i s h Columbia have been examined. The desmid f l o r a c o n s i s t s of 2 0 5 species and kh v a r i e t i e s i n 26 genera. Two genera, Spino-c l o s t e r i u m and Spinocosmarium, and s e v e r a l species of other genera, are reported f o r the f i r s t time from B r i t i s h Columbia. Seasonal changes i n the abundance and kinds of desmids o c c u r r i n g i n c o l -l e c t i o n s are noted. C u l t u r a l s t u d i e s on the v a r i a b i l i t y of T r i p l o c e r a s g r a -c i l e and T. v e r t i c i l l a t u r n were undertaken t o determine the v a l -i d i t y of s u b s p e c i f i c characters used i n the genus. These s t u d i e s showed t h a t the a p i c a l r a d i a t i o n of the s e m i c e l l (the number of lobes at the end of the s e m i c e l l ) can vary from b i r a d i a t e ( 2 -lobed) t o q u a d r i r a d i a t e (4-lobed) w i t h i n a s i n g l e clone. Thus i n the genus t h i s character must be discarded as a taxonomic c r i t e r -i o n . The morphology of the protuberances of the s e m i c e l l s was con-s t a n t i n both s p e c i e s , and i s a u s e f u l s u b s p e c i f i c c h a r a c t e r . A number of abnormal forms occurred i n c u l t u r e s but were not observed i n f i e l d c o l l e c t i o n s . The n u c l e a r c y t o l o g y of T r i p l o c e r a s was i n v e s t i g a t e d . T. v e r t i c i l l a t u r n has the l a r g e s t chromosomes yet reported f o r the Desmidiaceae, almost 2 0 u i n l e n g t h measured at l a t e prophase i n c o l c h i c i n e t r e a t e d c e l l s . The chromosome number f o r t h i s species s i s n = 1 5 - 2 0 . The chromosomes of T. g r a c i l e are s m a l l e r , but no chromosome counts were obtained f o r t h i s s p e c ies. i i TABLE OF CONTENTS Page Abstract i Table of Contents i i List of Tables i i i List of Illustrations iv I. Introduction 1 II. Material and Methods 3 III. Desmids from Eight Lakes in Southwestern British Columbia A. Literature 6 B» Results 7 C. Discussion 11 IV. Studies on Triploceras in Culture A. Literature 2 $ B. Results 32 C. Discussion 39 Literature Cited U6 i i i LIST OF TABLES Page T a b l e I . Desmids p r e s e n t i n e i g h t l a k e s f r o m S o u t h w e s t e r n B r i t i s h C o l u m b i a 13-24 T a b l e I I . D i s t r i b u t i o n a l r e c o r d s f o r T r i p l o c e r a s 27-29 T a b l e I I I . S i z e r a n g e s o f c e l l s o f T r i p l o c e r a s i n c u l t u r e s and c o l l e c t i o n s 3U i v LIST OF ILLUSTRATIONS P l a t e I. Map showing l a k e s i n v e s t i g a t e d n e a r Haney, B. C. P l a t e I I . P h o t o g r a p h s o f c o l l e c t i o n a r e a s a t G w e n d o l i n e Lake and P l a c i d Lake. P l a t e I I I . D r awings o f v a r i e t i e s o f T r i p l o c e r a s and r e l a t e d d e s r a i d s . P l a t e I V . Camera l u c i d a d r a w i n g s o f T r i p l o c e r a s . P l a t e V. Camera l u c i d a d r a w i n g s o f T r i p l o c e r a s i n c u l t u r e . P l a t e V I . Camera l u c i d a d r a w i n g s o f T r i p l o c e r a s v e r t i c i l -l a t u m i n c u l t u r e . P l a t e V I I . P h o t o g r a p h s o f T r i p l o c e r a s v e r t i c i l l a t u m and P l e u r o t a e n i u m s p i n u l o s u m . P l a t e V I I I . P h o t o g r a p h s o f T r i p l o c e r a s i n c u l t u r e . P l a t e I X . P h o t o g r a p h s o f chromosomes o f T r i p l o c e r a s v e r t i c i l l a t u m . 1 I . INTRODUCTION. Desmids a r e members o f t h e g r e e n a l g a l o r d e r Zygnema-t a l e s , c h a r a c t e r i z e d b y s e x u a l r e p r o d u c t i o n b y c o n j u g a t i o n o r f u s i o n o f amoeboid gametes. The desmids c o m p r i s e t h r e e o f t h e f o u r f a m i l i e s w i t h i n t h i s o r d e r , t h e M e s o t a e n i a c e a e , t h e Gona-t o z y g a c e a e , and t h e D e s m i d i a c e a e ( P r e s c o t t 1962). The f o u r t h f a m i l y , t h e Zygnemataceae, c o n t a i n s f i l a m e n t o u s a l g a e s u c h as t h e common S p i r o g y r a , Zygnema and M o u g e o t i a . The M e s o t a e n i a c e a e d i f f e r f r o m t h e Zygnemataceae b y h a v i n g o n l y u n i c e l l u l a r s p e c i e s whereas t h e Gonatozygaceae form s h o r t f i l a m e n t s and have i n a d d i t i o n m u c i l a g e p o r e s i n t h e c e l l w a l l . The D e s m i d i a c e a e may be u n i c e l l u l a r o r f i l a m e n t o u s b u t t h e c e l l s a l w a y s c o m p r i s e two h a l v e s , o r s e m i c e l l s , u s u a l l y i d e n t i c a l i n shape, and t h e c e l l w a l l a l w a y s has m u c i l a g e p o r e s . Most o f t h e D e s m i d i a c e a e have a c o n s t r i c t i o n , o r i s t h m u s , a t t h e r e g i o n where t h e two s e m i c e l l s j o i n . A l a r g e number o f desmid s p e c i e s have b e e n d e s c r i b e d . W i t h i n N o r t h A m e r i c a most o f t h e desmid s t u d i e s have b e e n f r o m c o l l e c t i o n s made i n t h e e a s t e r n o r s o u t h e a s t e r n p a r t o f t h e c o n t i n e n t . S i n c e r e l a t i v e l y few s t u d i e s have b e e n made i n w e s t e r n N o r t h A m e r i c a , one aim o f t h i s s t u d y was t o add t o t h e knowledge o f t h e d e s m i d f l o r a o f B r i t i s h C o l u m b i a . The taxonomy o f desmids i s b a s e d on t h e shape o f t h e c e l l and on t h e o r n a m e n t a t i o n o f t h e c e l l w a l l . R e c ent s t u d i e s have i n d i c a t e d t h a t some o f t h e m o r p h o l o g i c a l c r i t e r i a u s e d t o 2 d i s t i n g u i s h desmid s p e c i e s may n o t b e c o n s t a n t ( f o r example see G r o n b l a d and S c o t t 1955). One i m p o r t a n t f e a t u r e o f t h e desmid c e l l i s t h e shape o f t h e apex o f t h e c e l l when v i e w e d p e r p e n d i -c u l a r t o t h e p l a n e formed b y t h e i s t h m u s . The c e l l may be c y l i n d r i c a l , i n w h i c h c a s e t h e apex i s s a i d t o be o m n i r a d i a t e . The apex may b e e l l i p t i c a l ( b i r a d i a t e ) , t r i a n g u l a r ( t r i r a d i a t e ) o r many-angled ( t e t r a r a d i a t e , p e n t a r a d i a t e , e t c . ) . I t has b e e n f o u n d t h a t i n some desmid s p e c i e s t h e a p i c a l r a d i a t i o n may v a r y c o n s i d e r a b l y ( T a i l i n g 1950). The s e c o n d a i m o f t h i s i n v e s t i g a t i o n was t o s t u d y t h e r a n g e o f m o r p h o l o g i c a l v a r i a t i o n o c c u r r i n g i n two s p e c i e s o f T r i p l o c e r a s ( D e s m i d i a c e a e ) . T. g r a c i l e , t h e more w i d e l y d i s -t r i b u t e d s p e c i e s o f t h i s genus, h a s been r e g a r d e d as one o f t h e most p o l y m o r p h i c desmids ( T u r n e r 1892, West 1909, S m i t h 1921). S e v e r a l v a r i e t i e s have been d e s c r i b e d b u t some seem b a s e d on m i n o r m o r p h o l o g i c a l d i f f e r e n c e s . I n o r d e r t o d e t e r m i n e t h e v a l i d i t y o f t a x o n o m i c c h a r a c t e r s u s e d i n d i s t i n g u i s h i n g v a r i e t i e s o f T. g r a c i l e and T. v e r t i c i l l a t u m i t was n e c e s s a r y t o e s t a b l i s h c u l t u r e s so t h a t v a r i a b i l i t y , l i f e h i s t o r y and c y t o l o g y c o u l d be s t u d i e d under c o n t r o l l e d c o n d i t i o n s . 3 I I . MATERIAL AND METHODS C o l l e c t i o n s were made a t i r r e g u l a r i n t e r v a l s f r o m t h e f o l l o w i n g l a k e s n e a r V a n c o u v e r : ( T e x t f i g u r e 1) Como L a k e , Munday Lake and L o s t Lake i n C o q u i t l a m M u n i c i p a l i t y , 15 m i l e s e a s t o f Va n c o u v e r . These l a k e s a r e n e a r a r e s i d e n t i a l a r e a and a r e a c c e s s i b l e t o t h e p u b l i c b y s h o r t h i k i n g t r a i l s . M i k e L a k e , G w e n d o l i n e L a k e , P l a c i d L ake, Loon L a k e , B l a n e y Lake and M a r i o n L a k e , a p p r o x i m a t e l y 1*0 m i l e s e a s t o f Vancouver ( P l a t e I ) . M i k e Lake i s i n G a r i b a l d i P r o v i n c i a l P a r k and t h e r e m a i n i n g l a k e s a r e i n t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a R e s e a r c h F o r e s t . The l a k e s a r e s i t u a t e d among mountains and a r e n o t r e a d i l y a c c e s s i b l e t o t h e p u b l i c . TEXTFIGURE 1. MAP SHOWING LOCATION OF LAKES STUDIED. PITT LAKE BURRARD INLET O o MUNDAY L. L05T L. AREA IN PLATE I FRASER RIVER k Collections were usually made from the lake margin using a large basting pipette to pick up algae from the soft bottom material. Alternatively filamentous algae or mosses from the edge of the lake were squeezed to expel water that contained desmids. Plankton and material from Nuphar, Potamogeton, and Utricularia growing in the lakes were also collected. Water temperature was measured at each collection spot and the pH was determined using pHydrion paper. Water samples were taken to the laboratory where pH was checked with a Beckman meter. The algae were collected in small glass jars and kept in a refrigerator until they could be examined. Samples of each collection were examined i n i t i a l l y with a dissecting microscope in order to find cells of Triploceras which could then be isolated for culturing. Some of the desmids which were very rare in these collections were detected during this preliminary examination. The remainder of the desmid identifi-cation was done by examining several slides of material from each collection with a compound microscope. Standard references used for desmid identification were West and West (1904-1923), Krieger (1937), and Kossinskaya (I960). Camera lucida drawings were made of those desmids not readily identified using these monographs. The drawings were then compared with those in the literature. Isolation of cells for culturing was by the capillary pipette method of Pringsheim (1946). A l l cultures were clonal, the result of a single inoculated ce l l . Cells were placed in a modified soil-water medium prepared in the following way. Equal 5 parts of s o i l and pulverized peat (approximately 0.$ cc. of each) were placed i n a test tube with 20 cc. d i s t i l l e d water. The tubes were steamed for one hour or, alternatively, autoclaved for 30 minutes on each of three successive days. Additional inoculations were made into acid (pH 6.0) MXS medium (Waris 1953). Cultures were kept at 20°C with illumination by daylight fluorescent lamps at approximately 350 ft.-candles on a Iii hour light and 10 hour dark cycle. For cytological studies cultures of T. verticillatum were treated with 1$ colchicine before fixation. The colchicine was added to a culture the night before fixation in order to affect divisions occurring during the dark period. Cells were fixed i n 1;1 acetic acid-alcohol for 15 to 30 minutes. Staining was by the iron alum-acetocarmine method of Godward (King I960). Suit-able cells were squashed by rubbing the cover s l i p with the t i p of a dissecting needle as described by King (I960). 6 I I I . DESMIDS FROM EIGHT LAKES I N SOUTHWESTERN B. C. A. L i t e r a t u r e R e l a t i v e l y few s t u d i e s have b e e n made on t h e desmid f l o r a o f B r i t i s h C o l u m b i a . A l i s t o f 265 s p e c i e s i n 2k g e n e r a was c o m p i l e d b y W a i l e s (1925) f o r t h e s o u t h w e s t e r n p a r t o f t h e p r o -v i n c e . T h i s l i s t was sup p l e m e n t e d b y s h o r t p a p e r s on i s o l a t e d c o l l e c t i o n s f r o m t h e same a r e a ( W a i l e s 1930a, b , c, 1931a, b , c, 1932, 1933, W a i l e s & T i f f a n y 1929). Two l a k e s i n t h e Van-c o u v e r a r e a were examined b y W a i l e s . I n Como Lake 37 s p e c i e s i n 15 g e n e r a were i d e n t i f i e d ( W a i l e s 1930a) and i n Munday Lake 107 s p e c i e s i n 17 g e n e r a were r e p o r t e d ( W a i l e s 1930b, 1 9 3 1 a ) . The o n l y o t h e r r e s e a r c h on B r i t i s h C o l u m b i a desmids was t h a t o f C a r t e r (1935) on c o l l e c t i o n s made i n t h e 1920«s b y W. R. T a y l o r f r o m a l p i n e a r e a s o f e a s t e r n B r i t i s h C o l u m b i a i n t h e G l a c i e r N a t i o n a l P a r k r e g i o n . N i n e t y - t w o s p e c i e s i n LU g e n e r a were i d e n t i f i e d f r o m T a y l o r ' s c o l l e c t i o n s . 7 B. Results All of the lakes sampled are situated in forested areas (Plate II). The surrounding trees are mainly cedar (Thuja p l i - cata) and Douglas f i r (Pseudotsuga menziesii). Each lake has a boggy margin whose main components are Sphagnum papillosum and S. capillaceum. Drosera rotundifolia commonly grows in these marginal bogs. Further away from the lake margin there is a shrub zone made up principally of Ledum groenlandicum and Kalmia sp. Extensive beds of Nuphar polysepalum grow in the shallow areas of a l l lakes sampled. A bed of pond weed (Potamogeton sp.) is found in Mike Lake. Utricularia vulgaris and Vallisneria sp. are common in a l l the lakes. The pH of a l l the lakes ranges between when measured with paper indicator and between U.8 and 6 .5 with pH meter (2 hours after collection). Water temperatures measured at collection sites along the edges of the lakes vary from a low of 7-10°C during January and February to a high of 18-21°C during August. Desmid species identified from the lakes are listed in Table I. The flora of each lake differs somewhat both in com-position and in relative abundance of species. Filamentous des-mids, especially species of Desmidium, are abundant in Gwendoline Lake but in other lakes the only filamentous desmid which can be commonly found is Bambusina borreri. Three lakes, Loon, Lost and Placid, are exceptional because the rarely reported Pleurotaenium  spinulosum (Plate VII, fig. 5) is present in large quantities in each lake. In general the desmids which could be found most often 8 in collections were Cylindrocystis brebissonii, Netrium digitus, Closterium costatum, CI. libellula, CI. r a l f s i i var. hybridum, CI. ulna. Euastrum didelta, Xanthidium antilopaeum, X . anti- lopaeum var. polymazum, Hyalotheca dissiliens and Bambusina  borreri. Differences exist between the desmid flora of a given lake at different times of the year. In Mike Lake during the winter (January-February) the water level of the lake is 0.3-0.7 m higher than in the summer due to the increased rainfall during the winter. Water temperature is approximately 7°C in the lake and 5 to 7°C in the marginal areas flooded by the high water. The pH of the water is 5.0. Algae are not common in collections taken from the lake bottom. However in the flooded marginal areas diatoms (mainly species of Tabellaria and Fragilaria) occur along with several desmid species, the commonest being Cylindrocystis brebissonii, Micrasterias americana, and Xanthidium antilopaeum var. polymazum. In May the lake water level is slightly lower but there are s t i l l several shallow puddles covering parts of the marginal bog. Lake temperature is 11°C and water temperature in the shallow puddles is 15 to 16°C. The pH in both areas is U.5 to 5.0. In the lake the diatoms Tabellaria and Fragilaria are very abundant along with filaments of Mougeotia and Oedogonium. Desmids are s t i l l quite rare in collections from the lake bottom, altthough over 20 species are present. The commonest desmids are Closterium baillyanum and CI. ulna. In the warmer shallow areas a large variety of desmids is found. Cylindrocystis brebissonii (with abundant zygotes), 9 N e t r i u m d i g i t u s , and Tetmemorus b r e b i s s o n i i a r e e x t r e m e l y common. O t h e r desmids w h i c h a r e l e s s common i n c o l l e c t i o n s a r e S p i r o t a e n i a  c o n d e n s a t a , C l o s t e r i u m l i b e l l u l a , C l . l i b e l l u l a v a r . i n t e r r u p t u r n , C l . s t r i o l a t u m , E u a s t r u m d i d e l t a and H y a l o t h e c a d i s s i l i e n s . I n A u g u s t , b e c a u s e o f t h e low summer r a i n f a l l , t h e w a t e r l e v e l i s a t i t s l o w e s t f o r t h e y e a r ( a p p r o x i m a t e l y 10 cm. b e l o w t h e l e v e l o f t h e m a r g i n a l b o g ) . Water t e m p e r a t u r e i s 17-20°C and t h e pH r e m a i n s a t U.5-5.0. The dominant a l g a i s M o u g e o t i a s p . ( s t e r i l e ) . The desmid f l o r a r e a c h e s i t s maximum d i v e r s i t y a t t h i s t i m e , b u t most s p e c i e s o c c u r o n l y once o r t w i c e i n any c o l l e c t i o n . Many desmids a r e p r e s e n t i n c o l l e c t i o n s o n l y a t t h i s t i m e o f t h e y e a r . Common desmids a t t h i s t i m e a r e N e t r i u m d i g i t u s , S p i r o t a e n i a  c o n d e n s a t a , C l o s t e r i u m c o s t a t u m , C l . l i b e l l u l a , C l . setaceum, P l e u r o t a e n i u m e h r e n b e r g i i , Euastrum e l e g a n s , M i c r a s t e r i a s c o n f e r t a v a r . hamata, M. t r u n c a t a , and S t a u r a s t r u m a r c t i s c o n . D u r i n g l a t e O c t o b e r t h e w a t e r l e v e l r e m a i n s a t a p p r o x i m a t e l y t h e same l e v e l as f o r August b e c a u s e o f i n c r e a s i n g r a i n f a l l b u t t h e w a t e r t e m p e r a t u r e f a l l s t o about 10°C. The de s m i d f l o r a changes o n l y s l i g h t l y f r o m t h a t p r e s e n t i n August c o l l e c t i o n s . Those s p e -c i e s p r e s e n t i n t h e l a k e d u r i n g t h e warm summer months have d i s -a p p e a r e d f r o m t h e c o l l e c t i o n s . Many empty c e l l s and c e l l s p a r a -s i t i z e d b y f u n g i a r e s e e n . Common s p e c i e s d u r i n g O c t o b e r a r e N e t r i u m d i g i t u s , C l o s t e r i u m l i b e l l u l a , C l . setaceum, P l e u r o t a e n i u m  e h r e n b e r g i i , and S t a u r a s t r u m a r c t i s c o n . As w i n t e r approaches t h e t e m p e r a t u r e o f t h e l a k e w a t e r c o n t i n u e s t o f a l l . The w a t e r l e v e l r i s e s as a r e s u l t o f t h e 10 i n c r e a s e d w i n t e r r a i n f a l l . The number o f desmids i n c o l l e c t i o n s d e c r e a s e s u n t i l t h e y a g a i n become r a r e i n w i n t e r c o l l e c t i o n s . Q u a l i t a t i v e l y t h e desmid f l o r a changes f r o m t h a t c h a r a c t e r i s t i c o f t h e warmer autumn w a t e r s t o t h a t c h a r a c t e r i s t i c o f w i n t e r , w i t h v e r y few s p e c i e s p r e s e n t . 11 C. D i s c u s s i o n T h i s i n v e s t i g a t i o n combined w i t h t h o s e o f W a i l e s and C a r t e r and w i t h a r e c e n t s u r v e y ( S t e i n , u n p u b l i s h e d ) i n d i c a t e s t h a t t h e desmid f l o r a o f B r i t i s h C o l u m b i a i s among t h e most d i v e r s i f i e d i n t h e w o r l d . Over $00 s p e c i e s and 100 v a r i e t i e s have now been r e p o r t e d , l a r g e l y f r o m t h e s o u t h w e s t e r n c o a s t a l r e g i o n o f t h e p r o -v i n c e . The l a r g e number o f desmids f o u n d i n t h e c o a s t a l a r e a i s due i n p a r t t o t h e a c i d i c w a t e r p r e v a l e n t i n t h e a r e a , one o f t h e p r e r e q u i s i t e s f o r t h e development o f a d i v e r s e d esmid f l o r a , and i n p a r t t o t h e g r e a t e r number o f a l g a l c o l l e c t i o n s w h i c h have b e e n made i n t h i s a r e a . I t i s p r o b a b l e t h a t many more s p e c i e s w i l l b e added t o t h e desmid f l o r a when s t u d i e s a r e made on c o l l e c t i o n s f r o m o t h e r p a r t s o f t h e p r o v i n c e . B o t h q u a l i t a t i v e and q u a n t i t a t i v e d i f f e r e n c e s i n t h e desmid f l o r a o f t h e l a k e s s t u d i e d a r e e v i d e n t a t d i f f e r e n t s e a s o n s o f t h e y e a r . The t e m p e r a t u r e o f t h e w a t e r a p p e a r s t o be t h e m a j o r f a c t o r i n t h e development o f t h e d i v e r s e f l o r a o f t h e summer months. When w a t e r t e m p e r a t u r e e x c e e d s 10°C t h e number o f desmids i n t h e c o l l e c -t i o n s i n c r e a s e s g r e a t l y . The pH changes o f t h e w a t e r do n o t show any a n n u a l p a t t e r n and do n o t seem t o c o r r e l a t e w i t h any changes i n t h e d e s m i d f l o r a t h r o u g h o u t t h e y e a r . The w a t e r l e v e l o f t h e l a k e r i s e s d u r i n g t h e w i n t e r due t o i n c r e a s e d r a i n f a l l a t t h i s t i m e , b u t t h e r e seems t o be no r e l a t i o n between w a t e r l e v e l and t h e desmids p r e s e n t i n t h e l a k e . W i t h r e g a r d t o t h e i r abundance d u r i n g t h e y e a r t h r e e c l a s s e s o f desmids c a n be r e c o g n i z e d i n t h e l a k e s s t u d i e d . These a r e : 12 a) desmids t h a t a r e commonest i n c o l l e c t i o n s t a k e n d u r i n g t h e w i n t e r ( e . g . M i c r a s t e r i a s a m e r i c a n a ) . b) desmids t h a t appear i n c o l l e c t i o n s o n l y d u r i n g t h e summer. T h i s group i n c l u d e s t h e p l a n k t o n i c desmids ( e . g . S t a u r a s t r u m a r c t i s c o n ) and t h e m a j o r i t y o f o t h e r desmids i n c l u d i n g t h e two s p e c i e s o f T r i p l o c e r a s . c) desmids w h i c h a r e common i n c o l l e c t i o n s t h r o u g h o u t t h e y e a r ( e . g . N e t r i u m d i g i t u s , C y l i n d r o c y s t i s b r e b i s s o n i i ) . S e v e r a l new d esmid r e c o r d s f o r t h e p r o v i n c e a r e i n d i c a t e d b y a s t e r i s k s i n T a b l e I . The g e n e r a S p i n o c o s m a r i u m (S. q u a d r i d e n s ) and S p i n o c l o s t e r i u m (S. curvatum) have b e e n p r e v i o u s l y r e p o r t e d o n l y f r o m e a s t e r n N o r t h A m e r i c a . An e x t r e m e l y r a r e d e s m i d , P l e u r o t a e n i u m  s p i n u l o s u m , w h i c h has b e e n r e p o r t e d i n t h e l i t e r a t u r e o n l y s e v e n t i m e s s i n c e i t was d e s c r i b e d b y W o l l e i n 1881, i s p r e s e n t i n f i v e o f t h e e i g h t l a k e s examined. I n L o s t L ake, Loon Lake and P l a c i d Lake t h i s desmid i s p r e s e n t i n l a r g e numbers, b u t t h e r e a s o n s f o r t h i s abundance a r e unknown. P. s p i n u l o s u m may have a v e r y r e s t r i c t e d range o f t o l e r a n c e t o one o r more e n v i r o n m e n t a l f a c t o r s and t h e s e f a c t o r s may have b e e n a t t h e i r optimum f o r g r o w t h o f t h i s d e s m i d i n t h e l a k e s where i t was v e r y abundant. TABLE I DESMIDS PRESENT IN EIGHT LAKES FROM SOUTHWESTERN BRITISH COLUMBIA Symbo l s : I . I I . I I I . I V. M a r i o n Lake V. Loon Lake S u n d a y Lake V I . B l a n e y Lake L o s t Lake V I I . G w e n d o l i n e Lake M i k e Lake V I I I . P l a c i d Lake S p e c i e s p r e s e n t - S p e c i e s n o t p r e s e n t Not r e p o r t e d f r o m B r i t i s h C o l u m b i a i n t h e l i t e r a t u r e TAXON Lake Number I I I I I I IV V V I V I I V I I I G o n a t o z y g a c e a e Gonatozygon G. b r e b f s s o n i i ~ De B a r y G. b r e b i s s o n i i ~ v . l a e v e ( H i l s e ) West & West *G. k i n a h a n i ( A r c h . ) Rab. G. monotaenium ~ De B a r y M e s o t a e n i a c e a e C y l i n d r o c y s t i s C. b r e b i s s o n i i Menegh. N e t r i u m N. d i g i t u s ~" I t z i g s . & Rothe •w. lame l l o sum (Br e b . ) G r o r i b l . * v « n a e g e l i ( B r e b . ) K r i e g . - + + + - + - + - + c o n t i n u e d TABLE I. ( c o n t i n u e d ) I I I I I I I V V VI V I I V I I I * v . rhomboideum - + - + G r o r i b l . N. i n t e r r u p t u m _ _ _ + - -Lutkera. N. oblongum - - - + Lutkem. M e s o t a e n i a c e a e S p i r o t a e n i a S. c o n d e n s a t a - - + + + + B r e b . D e s m i d i a c e a e Arthrodesmus A. o c t o c o r n i s - - _ + - -E n r l Baxnbusina B. b o r r e r i + - + - + — K u t z . C l o s t e r i u m -*C1. acerosum - - - + + -( S c h r a n k ) E h r . C l . acutum - + - - - -B r e b . C l . angustatum + - + + K u t z . C l . a r c h e r i a n u m - - + + + C l e v e *C1. b a i l l y a n u m - + + + + + B r e b . C l . c o s t a t u m + - + + + C o r d a * v . W e s t i i - + - - + Cushman C l . c y n t h i a - - _ + - + De Not. -KGI. d e l p o n t e i - - - - + -— (ELebs) W o l l e C l . d i a n a e + - + + - + E h r . #v. arcuatum - - + + + ( B r e b . ) Rab. C l . didymotocum + + - + C o r d a C l . g r a c i l e + - + + - + B r e b . c o n t i n u e d TABLE I ( c o n t i n u e d ) I I I I I I v . elongatum West & West C I . i n t e r m e d i u m - + R<alfs C I . j e n n e r i - -R a l f s C I . j u n c i d u m - -R a l f s v . b r e v i o r - -( R a l f s ) Roy C l . k u t z i n g i i - -B r e b . C l . l e i b l e i n i i + -K u t z . C l . l i b e l l u l a + -Foc k e v . i n t e r m e d i u m - -(Roy & B i s s . ) West v . i n t e r r u p t u m - -(West & West) Donat *C1. l i n e a t u m E h r . v . c o s t a t u m - -W o l l e C l . l u n u l a + -N i t z s c h C l . m o n i l i f e r u m - -E h r . C l . n a v i c u l a - -( B r e b . ) Lutkem. v . erassum - -(West & West) G r o n b l . C l . p a r v u l u m - -N a g e l i v . angustum - -West & West C l . pronum - -B r e b . * C 1 . p s e u d o d i a n a e - -Roy C l . r a l f s i i - -B r e b . v . h y b r i d u m + -RaFI C l . r o s t r a t u m - -E h r . C l . setaceum - -E h r . TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V i l l i C l o s t e r i u m ( c o n t i n u e d ) C l . s t r i o l a t u m - _ + _ - + E h r . #C1. t o x o n - + + + -West C l . u l n a - + + + + + + + F o c k e Cosmarium C. a l p e s t r e - - _ + - -Roy & B i s s . C. amoenum - + + + - - + B r e b . c. angulosum - + + - + -B r e b . * c . annulatum v . e l e g a n s - -N o r d s t . + c. a u r i c u l a t u m - - - + - + -R e i n s c h c. binum + - - + - - -N o r d s t . c. b l y t t i i + - + + + W i l l e c. b o e c k i i - - - + - - -W i l l e c. -Menegh. c i r c u l a r e - - + - -R e i n s c h c. c l e v e i - -(Lund.) Lutkem. - + - + -c. connatum - - _ + - -B r e b . c. c o n t r a c t u m v . e l l i p s o i d e u m - -( E l f v . ) West & West + - + + c. cucumis - - - + - - -C o r d a c. c u c u r b i t a + - - + + • + + B r e b . c. d i f f i c i l e - - + - -Lutkem. •«c. formosulum v. n a t h o r s t i i - -( B o l d t ) West & W e s t + c. globosum - - - - + — c o n t i n u e d TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V I I I Cosmarlum ( c o n t i n u e d ) c. i s t h m i u m - - + - + - + West c. m a r g a r i t a t u r a Roy & B i s s . - + + + + c. m a r g a r i t i f e r u m - - + - - - -Menegh. c. m e n e g h i n i l - - + - -B r e b . c. m o n i l i f o r m e + - + - - - + R a l f s , G. n o v a e - s e r a l i a e - - - + - - - -W i l l e C. ornatum + + - + + + — R a l f s C. p o r t i a n u m + - + - - - -A r c h . C. pseudamoenura - - _ + - - - -W i l l e c. ps eudoconnatum f . m a j o r W i l l e - + - + c. ps eudopyramidatum - - - - - + - -N o r d s t . c. p u n c t u l a t u m + B r e b . c. pygraaeum + A r c h . c. pyramidatum B r e b . - — - + - + + + c. q u a d r i f a r i u m - - - + + + + Lund. c. q u i n a r i u m + — _ + - + Lund. G. r a l f s i i — _ - + — B r e b . C. r e g n e l l i i - - - + + - -W i l l e C. s e x a n g u l a r e - - - - + - -Lund. C. t a x i c h o n d r u m - - + - + - + Lund. C. tumidum - - - - - + - -Lund. C. venustum - _ — _ + _ -A r c h . c o n t i n u e d TABLE I ( c o n t i n u e d ) I I I I I I I V V VT V I I V I I I Cosmocladium *C. saxdnTcum - - - + - - - + De B a r y Desmidium »D. aptogonum - - - - - + + ~ B r e b . D. b a i l e y i - - - - + + ( R a T f s ) N o r d s t . D. c o a r c t a t u m + - - + - - + N o r d s t . D. c y l i n d r i c u m - - - + - -G r e v . *D. g r a c i l e p s - - - - - - - + ( N o r d s t . ) L a g e r h . D. s w a r t z i i + - _ + - - + Ag. D o c i d i u m D. b a c u l u m - _ _ _ + - + B r e b . *D. u n d u l a t u m + - - - + + B a i l . v . b i s a n n i c u m - - - - - - - + D u c e l l . E uastrum E. a f f i n e + + + + - -R a l f s , , E. ampullaceum - - - - - + - + R a l f s c E. ansatum - + - + - -R a l f s , E. b i d e n t a t u m - - _ + + + - + Nag. E. b i n a l e - - - + - - - + E h r . E. e r a s sum + - - + - + + + K u t z . * v . m i c h i g a n e n s e - - - - - + - + P r e s c o t t E. d e n t i c u l a t urn + + _ + + + + + Gay E. d i d e l t a - - + + _ + + + R a l f s -Lund. K u t z . B r e b . c o n t i n u e d TABLE I (continued) I I I I I I I V V V I V I I V I I I Euastrum (continued) »E, inerme + - - - + + i R a l f s ) Lund. E. insulare - - - + - -Roy E. intermedium + - - - - - - + ~ Cleve E. pinnatum - - - + - - + + Ralfs E. pulchellum - - - - - + ~~ Breb. E. sinuosum - - - - - - - + Lenorm. E. sublobatum - - - - + ~~ Breb. #E. verrucosum — v. alatum - - - - + Wo l i e Hyalotheca H. „ dissiliens + + _ + _ - + + Breb. H. mucosa - - - - + - + Ehr. Micrasterias M. americana - + _ + - - - + Ralfs M. conferta + - - + - - - + Lund. *v. hamata _ - _ + _ _ _ + Wolle M. denticulata - + - + + -— Breb. v. angulosa - - - + - - + West *-M. depauperata v. wolleT - + + + - - - + Cushman -»M. fimbriata ~ f. spinosa - - - + - -Biss. M. laticeps - - - + - -Nordst. Bailey )illife] Breb. West continued 20 TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V I I I M i e r a s t e r i a s ( c o n t i n u e d ) M, p i n n a t i f i d a + - -R a l f s M. r a d i a t a + + + + + Hass. M. r o t a t a - - + + - -R a l f s M. t r u n c a t a + + + + - + B r e b . •MM. t h o m a s i a n a - + - + + - + + -+ - + v . n o t a t a - - - - - -( N o r d s t . ) G r o r i b l . Onychonema 0. f i l i f o r m e + - - - - -Roy & B i s s . Penium P. m a r g a r i t a c e u m + - - + + -*" B r e b . P. polymorphum P e r t y P. r u f e s c e n s + G l e v e P. s p i r o s t r i o l a t u m ~~ B a r k e r P l e u r o t a e n i u m •M-P. b a c u l o i d e s (Roy & B i s s . ) P l a y f . P. coronatum + - _ + - -~ Rab. P. e h r e n b e r g i i + - + + - + + ~ De B a r y P. minutum •?• ^ * •sj- + [ R a l f s ) D e l p . * v . g r a c i l e - - - + - + ( W i l l e ) K r i e g e r * v . r e c t i s s i m u m - - - + - -(West & West) K r i e g e r P. nodosum - - - + + + + ( B a T l . ) Lund. *P. s p i n u l o s u m - - + + + - + ( W o l l e ) B r u n e i P. t r a b e c u l a - - + + -~ N a g e l i v. r e c t u m + - + - + + West & West c o n t i n u e d TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V I I I Sphaerozosma S. excavatum - - - - - - + R a l f s S. g r a n u l a t u m - - _ + - - + + Roy & B i s s . S p i n o c l o s t e r i u m •M-S. cur v a t u m * - - - - - - + ~ ( B a i l ) P r e s c o t t S p i n o c o s m a r i u m •B-S. q u a d r i d e n s + - - - - - - - + ~ (Wood) P r e s c . & S c . S p o n d y l o s i u m S. p u l c h e l l u m - + + - - -~ A r c h . S. p u l c h r u m + - - + - - + + ~ ( B a i l . ) A r c h . S t a u r a s t r u m -*S. a c u l e a t u m - - _ + - -~ ( E h r . ) Menegh. S. a l t e r n a n s - - _ + - -- B r e b . -»S. a n a t i n u m + - - + - + Cooke & W i l l s #v. grande - - - - - - - + West & West •K-V. l a g e r h e i m i i - - - - + (Scnmid.) West & West S. a r a c h n e - + + + - -~ R a i l s S. a r c t i s c o n - - _ + - - - + ( E h r . ) Lund. S. arcu a t u m - - - + - - - + ~ N o r d s t . *S. a r i s t i f e r u m — v . p r o t u b e r a n s - - - - - - + West & West #S. aversum - - - - + ~ Lund. S. b r a c h i a t u m - - - + - - - + ~ R a l f s S. b r a s i l i e n s e ~ v . l u n d e l l i i + - _ - - + - + West & West S. c e r a s t e s - - _ + - + - + ~ Lund. S. c l e v e i - - - - - + - + ( W i t t r . ) Roy & B i s s . c o n t i n u e d TABLE I ( c o n t i n u e d ) I I I I I I IV V 71 V I I V I I I S t a u r a s t r u m ( c o n t i n u e d ) S. curva'tum — — + - + _ + West S. c y r t o c e r u m + - + - - -B r e b . S. f o r f i c u l a t u m _ — - + - + - -Lund. S. f u r c a t u m — — + - - - -B r e b . S. f u r c i g e r u m - - - + + - -B r e b . * f . a r m i g e r a - - + - + - -( B r e b . ) N o r d s t . S. g l a d i o s u m - - - + - - - -T u r n . S. g r a c i l e + + + + - - -R a i l ' s v . nanum + -W i l l e #S. g r a l l a t o r i u m + N o r d s t . S. grande - - - + - - - -B u l n h . S. hexacerum - _ - _ - + - -W i t t r . S. i n c o n s p i c u u m - + + - + + + N o r d s t . S. i n f l e x u m — + - _ - - -B r e b . #S. l o n g i s p i n u m + ( B a i l . ) A r c h . S. m a r g a r i t a c e u m - + - + - - - + Menegh. S. m i n n e s o t e n s e - - + - - -W o l l e #S. m o n t i c u l o s u m + - + - - - -B r e b . S. murieatum - + + + - - + -B r e b . •KS. n a t a t o r + - - + - - - -West S. n e g l e c t u m + - + - - - -West S. o p h i u r a + - + - + + + Lund. c o n t i n u e d 23 TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V I I I S t a u r a s t r u m ( c o n t i n u e d ) S. o r b i c u l a r e v . depressum - - + - - - -Roy & B i s s . S. pachyrhynchum - - - - + - -N o r d s t . S. paradoxura + - - + - - + + Meyen #S. p i l o s u m - - - + - -(Nag.) A r c h . S. polymorphum — aw + + - - - -breD. S. p u n c t u l a t u m + + + - - - -B r e b . S. scabrum - - - - + - -B r e b . *S. s u b c r u c i a t u m - - - - + - -Cooke & W i l l s S. subscabrum - - - + - -N o r d s t . S. t e t r a c e r u m _ + + - + + + R a l f s f . t r i g o n a - - - + - - - -Lund. S. t o h o p e k a l i g e n s e + - - + - - - -W o l l e S. v e s t i t u m - - - + - - + -R a l f s •K-V. subanatinum - - - + - - - + West & West Staurodesmus 3 . c o n v e r g e n s - - + - - -( E h r . ) T e i l . s. c u s p i d a t u s - + - - - -(Breb.) T e i l . s. d e j e c t u s v . a p i c u l a t u s + -( B r e b . ) C r o a s d a l e + s. d i c k i e i - -( R a l f s ) L i l i e r o t h + v . c i r c u l a r i s - - - + + -( T u r n . ) C r o a s d a l e v . rhomboideus - - - + - - + (West & West) L i l i e r o t h *s. g l a b r u s v . r a l f s i i - - + - - -(West & West) T e i l . c o n t i n u e d 2 U TABLE I ( c o n t i n u e d ) I I I I I I I V V V I V I I V I I I Staurodesmus ( c o n t i n u e d ) -H-S. i n d e n t a t u s - - - - - - - + ~ (West & West) T e i l . S. j oshuae + + _ + - - + + ""' (Gutw.) T e i l . S. subpygmaeus - - _ + - -"* (West; f j r o a s d a l e #S. s u b t r i a n g u l a r i s - - _ + - - - + (Borg e ) T e i l . S. s u b u l a t u s - - - + - -( K u t z . ) C r o a s d a l e S. t r i a n g u l a r i s - - - + - -~ ( L a g e r h . ) T e i l . Tetmemorus T. b r e b i s s o n i i - + + + + + - + ~ (Menegh.) R a l f s T. g r a n u l a t u s - + + + - + - + ~ ( B r e b . ) R g l f a T. l a e v i s - + + - - + - + ~ ^ K u t z . ) R a l f s T r i p l o c e r a s T. g r a c i l e - _ + - + + + ~~ B a i l e y * v . b i d e n t a t u m - - _ + - - - + N o r d s t . #T. v e r t i c i l l a t u m + - - + - - - + ~ B a i l e y X a n t h i d i u m X. a n t i l o p a e u m + + + + - - - + ~ (B r e b . ) K u t z . v. h e b r i d a r u m - + _ _ + West & West v . polymazum + + + + + + - + N o r d s t . X. armatum - + - - - - + "" ( B r e b . ) Rab. * v . c e r v i c o r n e - - + West &>West v . f i s s u m + -N o r d s t . -H-X. c o n t r o v e r s u m - -- West & West X. c r i s t a t u m + -~ B r e b . - + 2$ I V . S t u d i e s on T r i p l o c e r a s i n C u l t u r e . A. L i t e r a t u r e . L i t e r a t u r e r e f e r e n c e s t o T r i p l o c e r a s a r e a l m o s t e x c l u s i v e l y c o n c e r n e d w i t h d i s t r i b u t i o n a l r e c o r d s o r w i t h d e s c r i p t i o n s o f new t a x a . C e l l s o f t h e genus were f i r s t c o l l e c t e d b y J . W. B a i l e y i n 181*7 f r o m ponds i n New J e r s e y and Rhode I s l a n d . Drawings s e n t b y him t o R a l f s were p u b l i s h e d b y R a l f s (181*8) as D o c i d i u m v e r t i -c i l l a t u m B a i l e y b u t a n o t e was i n c l u d e d s t a t i n g t h a t B a i l e y p r o p o s e d t o e r e c t a new genus f o r t h e p l a n t . L a t e r , h a v i n g d i s c o v e r e d a d d i t i o n a l m a t e r i a l i n G e o r g i a and F l o r i d a , B a i l e y ( l 8 $ l ) d e s c r i b e d t h e genus T r i p l o c e r a s w i t h two s p e c i e s , T. v e r t i c i l l a t u m ( B a i l e y ) B a i l e y ( P l a t e V I I , f i g . 1) and T. g r a c i l e B a i l e y ( P l a t e I V , f i g . 1 ) . I n 1937 K r i e g e r r e c o g n i z e d s i x s p e c i e s o f T r i p l o c e r a s . I n a d d i t i o n t o B a i l e y ' s two s p e c i e s t h e s e a r e T. a u s t r a l i a n u m (Borge) K r i e g e r , T. a b b r e v i a t u m T u r n e r , T. s p i n u l o s u m K i s s e l e v , and T. s i m p l e x A l l o r g e . The l a s t t h r e e s p e c i e s have b e e n removed t o a new genus, T r i p l a s t r u m I y e n g a r and Ramanathan 191*2 ( s e e G a u t h i e r -L i e v r e I 9 6 0 ) , b e c a u s e r i n g s o f p r o t u b e r a n c e s a r e l a c k i n g and b e c a u s e o f t h e i r s m a l l s i z e . The r a r e l y c o l l e c t e d T. a u s t r a l i a n u m ( P l a t e I I I , f i g . 11*) was p l a c e d b y S c o t t as a s p e c i e s o f P l e u r o -t a e n i u m b e c a u s e i t s o m n i r a d i a t e apex d i f f e r s f r o m t h e b i r a d i a t e t o q u a d r i r a d i a t e apex p r e s e n t i n T. g r a c i l e and T. v e r t i c i l l a t u m ( S c o t t and P r e s c o t t 1 9 $ 8 ) . T h e r e f o r e B a i l e y ' s o r i g i n a l s p e c i e s a r e now c o n s i d e r e d t o be t h e o n l y members o f t h e genus. T r i p l o c e r a s i s d i s t i n g u i s h e d f r o m P l e u r o t a e n i u m and D o c i d i u m , 26 m o r p o l o g i c a l l y t h e most s i m i l a r d e s m i d s , b y t h e shape o f t h e s e m i c e l l apex. I n T r i p l o c e r a s ( P l a t e V, f i g . 9, l o , 1 1 , 1 3 , l U , 16) i t i s 2- t o l i - l o b e d ( b i r a d i a t e t o q u a d r i r a d i a t e ) and c y l i n -d r i c a l , o r o m n i r a d i a t e , i n b o t h P l e u r o t a e n i u m ( P l a t e I I I , f i g . 2) and D o c i d i u m ( P l a t e I I I , f i g . 1 ) . I n b o t h s p e c i e s o f T r i p l o c e r a s t h e l a t e r a l w a l l s o f t h e s e m i c e l l s a r e ornamented w i t h r e g u l a r w h o r l s , o r v e r t i c i l s o f p r o t u b e r a n c e s , g i v i n g t h e c e l l i t s c h a r a c t e r i s t i c appearance ( P l a t e I V , f i g . 1; P l a t e V, f i g . 12, 17; P l a t e V I , f i g . $ ) . S i n c e i t s d e s c r i p t i o n T. g r a c i l e has b e e n c o l l e c t e d many t i m e s t h r o u g h o u t t h e w o r l d . T. v e r t i c i l l a t u m has a more r e s t r i c t e d d i s t r i b u t i o n , a l m o s t a l l r e c o r d s b e i n g f r o m N o r t h A m e r i c a . The d i s t r i b u t i o n a l r e c o r d s o f b o t h s p e c i e s a r e summarized i n T a b l e I I . P a p e r s w h i c h have n o t b e e n s e e n a r e l i s t e d i n p a r e n t h e s e s . R e f e r e n c e s t o t h e s e p a p e r s were o b t a i n e d f r o m K r i e g e r ( 1 9 3 7 ) , Moura and S i l v a ( 1 9 3 8 ) , K o s s i n s k a y a ( I 9 6 0 ) , and G a u t h i e r - L i e v r e ( I 9 6 0 ) . 27 TABLE I I DISTRIBUTIONAL RECORDS FOR TRIPLOCERAS L o c a l i t y A u s t r a l i a T. g r a c i l e T. v e r t i c i l l a t u r a R e f e r e n c e New Z e a l a n d S o u t h e a s t A s i a I n d i a , C e y l o n + + (Borge 1896) (F . M. B a i l e y 1898) P l a y f a i r 1907, 1910 West 1909 P r e s c o t t & S c o t t 1952 S c o t t & P r e s c o t t 1958 M a s k e l l 1880, 1882, 1888 M a s k e l l 1885 N o r d s t e d t 1888 A r c h e r 1665 (Moebius 1892) ( G u t w i n s k i 1902) K r i e g e r 1932 Vaas & S a c h l a n 191*8 S k u j a 191*9 Behre 1956 S c o t t & P r e s c o t t 196l Hobson 1863 T u r n e r 1892 West & West 1902 F r i t s c h 1907 Crow 1923 28 L o c a l i t y F i n l a n d , R u s s i a TABLE I I ( c o n t i n u e d ) T. g r a c i l e T. v e r t i c i l l a t u m R e f e r e n c e A f r i c a S o u t h A m e r i c a N o r t h A m e r i c a N. E. U. S. A. S. E. U. S. A. ( W i t t r o c k 1869) ( L u n d e l l I87I) E l f v i n g 1881 H i r n 1903 G r o n b l a d 1920, 1936 ( R o l l 1923, 1927) ( K o s s i n s k a y a i960) ( B o u r r e l l y 1957) G r o n b l a d , Prowse & S c o t t 1958 Woodhead & Tweed 1959 G a u t h i e r - L i e v r e i960 N o r d s t e d t 1877 ( B o r g e s e n I89O) G r o n b l a d 1945 Wood 1874 W o l l e 1892 Cushman 1905 H y l a n d e r 1928 G r o n b l a d 1956 Brown 1930 P r e s c o t t & S c o t t 1942 S c o t t & G r o n b l a d 1957 Schumacher 1958 29 L o c a l i t y TABLE I I ( c o n t i n u e d ) T. g r a c i l e T. v e r t i c i l l a t u m R e f e r e n c e S. E. U. S. A. ( c o n t i n u e d ) C e n t r a l U. S. A. E a s t e r n Canada A l a s k a W h i t f o r d 1958 West & West I896 S m i t h 1924 Andrews 1926 T a y l o r 1934 I r e n e e - M a r i e 1938, 1952, 1959a, b Hughes 1950 S m i t h 1921 Saunders 1901 I r e n e e - M a r i e and H i l l i a r d 1963 B r i t i s h C o l u m b i a + W a i l e s 1930a 30 Ten v a r i e t i e s o f T. g r a c i l e a r e r e c o g n i z e d b y K r i e g e r (1937). T. g r a c i l e v a r . g r a c i l e i s shown on P l a t e I V , f i g . 1. The o t h e r v a r i e t i e s a r e shown on P l a t e I I I and a r e s v . b i d e n t a t u m N o r d t s t e d t v . q u a d r i l o b a t u m T u r n e r v . d e n t i c u l a t u m ( P l a y f a i r ) West v . robustum G. S. West v . e l e g a n s (Borge) K r i e g e r v . t r i d e n t a t u m ( M a s k e l l ) v . i a t i c e p s N o r d s t e d t K r i e g e r v . montanum Cushman v. a c u l e a t u m N o r d s t e d t Three a d d i t i o n a l v a r i e t i e s d e s c r i b e d r e c e n t l y f r o m A f r i c a a r e : v . sudanense G r o n b l a d , Prowse and S c o t t v. a f r i c a n a Woodhead and Tweed v . t o r r i d a Woodhead and Tweed K r i e g e r (1937) r e c o g n i z e d t h r e e v a r i e t i e s o f T. v e r t i c i l - l a t u m shown on P l a t e I I I and p l a t e V I , f i g . 5 and t h r e e a d d i t i o n a l v a r i e t i e s have been d e s c r i b e d s i n c e t h e n . The v a r i e t i e s o f T. v e r t i c i l l a t u m a r e : v a r . v e r t i c i l l a t u m B a i l e y v a r . superbum ( M a s k e l l ) N o r d s t e d t v a r . t u r g i d u m ( W o l l e ) Cushman v a r . t u r g e s c e n s S c o t t & G r o n b l a d v a r . t a y l o r i i S c o t t & G r o n b l a d v a r . m i n o r G a u t h i e r - L i e v r e L i t t l e i s known o f t h e e c o l o g i c a l r e q u i r e m e n t s o f T r i p l o c e r a s . I n N o r t h A m e r i c a t h e genus i s u s u a l l y f o u n d i n s l i g h t l y a c i d i c ponds and l a k e s . I t has a l s o been r e p o r t e d f r o m d i t c h e s and swampy a r e a s ( S c o t t and G r o n b l a d 1957) and f r o m t h e 31 b l a d d e r s o f U t r i c u l a r i a (Schumacher 1958). Low pH o f t h e w a t e r does n o t seem t o be r e q u i r e d b e c a u s e K r i e g e r (1932) r e p o r t e d f i n d i n g T. g r a c i l e i n J a v a i n ponds w i t h pH f r o m 5 t o o v e r 8. Vaas and S a c h l a n (1948) r e p o r t e d T. g r a c i l e f r o m J a v a i n a s h a l l o w l a k e w i t h v e r y l ow c a l c i u m c o n c e n t r a t i o n and pH o f 6.8 t o 7.0. T. g r a c i l e was r e p o r t e d f r o m A l a s k a n l a k e s w i t h pH 6.6-6.8 and t e m p e r a t u r e 7.0 -15.2°C ( I r e n e e - M a r i e and H i l l i a r d 1963). F r i t s c h (1907) n o t e d t h a t T. g r a c i l e was a dominant e l e m e n t o f t h e a l g a l f l o r a o f f e r r u g i n o u s p o o l s i n C e y l o n w h i c h were c h a r a c t e r i z e d b y h a v i n g a r e d g r a n u l a r d e p o s i t o f f e r r i c h y d r o x i d e on t h e b o t t o m o f t h e p o o l and on t h e p l a n t s i n t h e p o o l . Sphagnum i s o f t e n p r e s e n t a r o u n d l a k e s where T r i p l o c e r a s i s f o u n d ( K r i e g e r 1932) a l t h o u g h a r e a s w i t h Sphagnum a r e known t o be e x c e l l e n t f o r t h e growth o f desmids i n g e n e r a l ( P r e s c o t t 19U8). D a t a f o r T. v e r t i c i l l a t u m a r e l a c k i n g b u t i n N o r t h A m e r i c a t h i s s p e c i e s i s f r e q u e n t l y f o u n d i n t h e same c o l l e c t i o n s t h a t c o n t a i n T. g r a c i l e . T h i s w o u l d i n d i c a t e t h a t t h e two s p e c i e s have s i m i l a r e n v i r o n m e n t a l r e q u i r e m e n t s . 32 B. R e s u l t s . The morphology o f t h e v e r t i c i l l a t e p r o t u b e r a n c e s i s u s e d t o d i s t i n g u i s h t h e two s p e c i e s o f T r i p l o c e r a s . I n T. g r a c i l e t h e p r o t u b e r a n c e s a r e c o n i c a l and may be t i p p e d w i t h one t o t h r e e s p i n e s i n some o f t h e v a r i e t i e s ( P l a t e I I I , f i g . 10, 11$ P l a t e I V , f i g . 1). I n T. v e r t i c i l l a t u m t h e p r o t u b e r a n c e s a r e b r o a d w i t h a c e n t r a l d e p r e s s i o n , p r o d u c i n g an e m a r g i n a t e o u t l i n e when v i e w e d f r o m t h e s i d e ( P l a t e V I , f i g . 5, 6). The r i m o f t h e p r o t u b e r a n c e i s some-t i m e s s p i n o s e i n v a r i e t i e s o f t h i s s p e c i e s ( P l a t e I I I , f i g . 12). The c h l o r o p l a s t s o f b o t h s p e c i e s a r e a x i a l w i t h s e v e r a l l o n g i t u d i n a l l o b e s r a d i a t i n g f r o m a c e n t r a l s t r a n d c o n t a i n i n g a v a r i a b l e number o f p y r e n o i d s . The n u c l e u s i s s i t u a t e d i n t h e i s t h m u s r e g i o n e n c l o s e d b y t h e l o b e s o f t h e c h l o r o p l a s t s . T r i p l o c e r a s i s p r e s e n t i n f i v e o f t h e l a k e s sampled f r o m J u l y t o November ( T a b l e I ) . T. g r a c i l e i s f o u n d i n f o u r l a k e s and T. v e r t i c i l l a t u m i s i n t h r e e l a k e s . B o t h a r e r a r e i n any one c o l l e c t i o n b u t T. v e r t i c i l l a t u m i s f o u n d more o f t e n t h a n T. g r a c i l e . T. g r a c i l e v a r . b i d e n t a t u m ( P l a t e I V , f i g . 2) i s p r e s e n t i n M i k e and M a r i o n Lakes b u t i s e x t r e m e l y r a r e . No s e x u a l s t a g e s o f T r i p l o c e r a s were f o u n d . C e l l s i s o l a t e d i n t o m i n e r a l m e d i a f a i l t o grow, b u t g r o w t h o c c u r s when c e l l s a r e i s o l a t e d i n t o s o i l - p e a t medium. Three c l o n e s o f T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m and one o f T. g r a c i l e v a r . g r a c i l e e s t a b l i s h e d f r o m 1963 c o l l e c t i o n s f r o m M i k e Lake and M a r i o n Lake. C e l l s o f b o t h s p e c i e s a t t a c h b y a m u c i l a g i n o u s s t a l k t o s o i l p a r t i c l e s o r t o t h e s i d e o f t h e c u l t u r e t u b e . M i g r a t i o n o f t h e 33 c e l l s may o c c u r b y s e c r e t i o n o f a t r a i l o f m u c i l a g e w h i c h r e m a i n s b e h i n d on t h e g l a s s s u r f a c e . D i v i d e d c e l l s sometimes r e m a i n a t t a c h e d i n a g e l a t i n o u s c y l i n d e r f o r m i n g a p s e u d o f i l a m e n t o u s s t r u c t u r e w i t h t h e c e l l s s e p a r a t e d f r o m each o t h e r . I n o l d c u l t u r e s o f T. g r a c i l e an amorphous mass o f m u c i l a g e may f o r m i n w h i c h c e l l s become t r a p p e d . C e l l s embedded i n t h e m u c i l a g e o f t e n d e v e l o p i n t o a bnormal f o r m s . The m o r p h o l o g y o f c e l l s i n c u l t u r e does n o t d i f f e r g r e a t l y f r o m t h a t o f c e l l s p r e s e n t i n l a k e c o l l e c t i o n s . The s i z e o f t h e c e l l s i n c u l t u r e i s s m a l l e r r e s u l t i n g i n t h e p r e s e n c e o f f e w e r r i n g s o f p r o t u b e r a n c e s on t h e s e m i c e l l s ( P l a t e V I I , f i g . U). No v a r i a -t i o n s i n t h e m o r p h o l o g y o f t h e p r o t u b e r a n c e s a r e o b s e r v e d , t h o s e o f T. v e r t i c i l l a t u m r e m a i n i n g e m a r g i n a t e and t h o s e o f T. g r a c i l e r e m a i n i n g as a c u t e s p i n e s ( P l a t e V, f i g . 12, 1 7 ) . C h l o r o p l a s t m o r p h o l o g y rem a i n s unchanged, w i t h s i x t o n i n e l o n g i t u d i n a l c h l o r o -p l a s t l o b e s r a d i a t i n g f r o m an a x i a l c h l o r o p l a s t s t r a n d c o n t a i n i n g s e v e n t o t e n p y r e n o i d s . Measurements o f c e l l s i n c u l t u r e and i n c o l l e c t i o n s a r e compared i n T a b l e I I I . 3a TABLE I I I S I Z E RANGES OF CELLS OF TRIPLOCERAS IN CULTURES AND COLLECTIONS S i z e i n u i n C u l t u r e i n C o l l e c t i o n T. g r a c i l e L. 22$ - 1*30 1*20 - 1*90 ¥. 30 - 35 28 - 37 N. 8 - 13 10 - 13 T. v e r t i c i l l a t u m L. 280 - 1*50 415 - 1*90 ¥. 38 - 1*9 37 - 1*5 N. 9 - 13 13 - 17 L. = l e n g t h o f c e l l W. = maximum w i d t h o f c e l l a t s e m i c e l l b a s e N. = number o f r i n g s o r v e r t i c i l s o f p r o t u b e r a n c e s V a r i a t i o n s i n t h e mor p h o l o g y o f t h e s e m i c e l l apex a r e r e g u l a r l y o b s e r v e d i n b o t h T. g r a c i l e and T. v e r t i c i l l a t u m . The s e m i c e l l a p i c e s o f T. g r a c i l e a r e u s u a l l y b i r a d i a t e ( P l a t e V, f i g . 9) b u t a p p r o x i m a t e l y f i v e p e r c e n t o f t h e c e l l s i n c u l t u r e have a t l e a s t one apex w h i c h i s t r i r a d i a t e ( P l a t e I V , f i g . 5). The a p i c a l l o b e s may be t i p p e d w i t h one o r two s p i n e s ( P l a t e I V , f i g . 7j P l a t e V, f i g . 10, 13). F i e l d c o l l e c t i o n s a l s o c o n t a i n c e l l s w i t h t r i r a d i a t e a p i c e s . A few c e l l s w i t h q u a d r i r a d i a t e s e m i c e l l a p i c e s a r e o b s e r v e d i n T. g r a c i l e c u l t u r e s ( P l a t e V, f i g . 11, 11*). The c e l l s o f T. v e r t i c i l l a t u m u s u a l l y have b i r a d i a t e s e m i -c e l l a p i c e s ( P l a t e V I , f i g . 5, 6, 9) b u t a g a i n about f i v e p e r c e n t 35 o f t h e c e l l s i n c u l t u r e have a t l e a s t one t r i r a d i a t e s e m i c e l l apex ( P l a t e I V , f i g . 8, 11; P l a t e V, f i g . 16). C e l l s w i t h one b i r a d i a t e and one t r i r a d i a t e a p e x a r e p r e s e n t i n f i e l d c o l l e c t i o n s ( P l a t e Y H , f i g . 1). C e l l s w h i c h h ave e x t r a p r o t u b e r a n c e s n o t a s s o c i a t e d w i t h t h e r e g u l a r w h o r l s on t h e c e l l s a r e o b s e r v e d i n c u l t u r e s o f T. g r a c i l e . These e x t r a p r o t u b e r a n c e s a r e u s u a l l y l o c a t e d b etween t h e a p i c a l two o r t h r e e w h o r l s on t h e s e m i c e l l and a r e n e v e r p r e s e n t n e a r t h e b a s e o f t h e s e m i c e l l ( P l a t e I V , f i g . 6; P l a t e V, f i g . 15). E x t r a p r o t u b e r a n c e s a r e r a r e l y f o u n d on c e l l s f r o m c u l t u r e s o f T. v e r t i c i l l a t u m . They a r e u s u a l l y p r e s e n t i n t h e r e g u l a r w h o r l s g i v i n g t h e s e w h o r l s o f p r o t u b e r a n c e s a v e r y crowded appearance ( P l a t e V I , f i g . 6, upper s e m i c e l l ) . I n o t h e r c a s e s t h e r e may be p r o t u b e r a n c e s l a c k i n g w i t h i n one o r more o f t h e w h o r l s ( P l a t e V I , f i g . 6, l o w e r s e m i c e l l ) . I n o l d c u l t u r e s o f T. g r a c i l e c e l l s w i t h a b n o r m a l l y shaped s e m i c e l l s a r e fo r m e d . A f t e r d i v i s i o n t h e new s e m i c e l l does n o t e l o n g a t e i n t o t h e n o r m a l c y l i n d r i c a l f o r m . The u s u a l r e s u l t i s a s h o r t s w o l l e n s e m i c e l l ( P l a t e I V , f i g . U ) . I n an extreme c a s e t h e s e m i c e l l becomes b u l b o u s , g i v i n g t h e c e l l t h e appearance o f a c l u b ( P l a t e V I I I , f i g . 2). R a r e l y t h e d e v e l o p i n g s e m i c e l l becomes b i f u r c a t e ( P l a t e V I I I , f i g . 1). These a b n o r m a l i t i e s a r e sometimes o b s e r v e d i n p a i r s , t h e r e s u l t o f d i v i s i o n o f a s i n g l e c e l l . When i s o l a t e d i n t o f r e s h medium n o r m a l s e m i c e l l s a r e p r o d u c e d a t subsequent c e l l d i v i s i o n s . F a i l u r e o f c y t o k i n e s i s i n T. g r a c i l e r e s u l t s i n t h e 36 f o r m a t i o n o f a b i n u c l e a t e c e l l i n w h i c h t h e two p a r e n t s e m i c e l l s r e m a i n c o n n e c t e d b y an i n f l a t e d c e n t r a l a r e a . T h i s c o n n e c t i n g r e g i o n i s u s u a l l y i r r e g u l a r i n shape w i t h p r o t u b e r a n c e s d i s t r i b u t e d a t random b u t i n some c a s e s t h i s c e n t r a l r e g i o n has one o r two e x t e n -s i o n s f r o m i t w h i c h m o r p h o l o g i c a l l y a r e t h e same as t h e a p i c a l p a r t o f a n o r m a l s e m i c e l l ( P l a t e I V , f i g . 3; P l a t e V, f i g . 8 ) . Such a c e l l i s r e l a t i v e l y common i n o l d c u l t u r e s o f T. g r a c i l e , e s p e c i a l l y i n c e l l s t r a p p e d i n s i d e a c c u m u l a t e d m u c i l a g e . Young c u l t u r e s o f T. g r a c i l e c o n t a i n v e r y few abnormal c e l l s b u t t h e number o f a b n o r m a l i t i e s i n c r e a s e s s t e a d i l y as t h e c u l t u r e ages. A p p r o x i m a t e l y two p e r c e n t o f c e l l s i n o l d c u l t u r e s have a b n o r m a l s e m i c e l l s o r a r e b i n u c l e a t e c e l l s . I n c u l t u r e s o f T. v e r t i c i l l a t u m a b n o r m a l l y - s h a p e d c e l l s a r e r a r e , a l m o s t n o n e x i s t e n t i n young c u l t u r e s and l e s s t h a n one p e r c e n t o f t h e c e l l s i n o l d c u l t u r e s . S h o r t e n e d s e m i c e l l s w i t h o r w i t h o u t p r o t u b e r a n c e s o c c u r ( P l a t e V I I , f i g . 2, 3 ) . C e l l s w i t h t w i s t e d o r s w o l l e n s e m i c e l l s h a v i n g i r r e g u l a r o r n a m e n t a t i o n i n t h e s w o l l e n r e g i o n a r e a l s o p r o d u c e d i n o l d c u l t u r e s ( P l a t e I V , f i g . 9, 10; P l a t e V I , f i g . 7 ) . D i v i s i o n a n o m a l i t i e s due t o t h e f a i l u r e o f c y t o k i n e s i s o c c u r b u t t h e c e n t r a l r e g i o n o f t h e b i n u c l e a t e c e l l u s u a l l y r e m a i n s i r r e g u l a r l y s w o l l e n ( P l a t e V I , f i g . 8 ) . The f o r -m a t i o n o f e x t e n s i o n s f r o m t h e c e n t r a l r e g i o n w h i c h r e s e m b l e a n o r -m a l s e m i c e l l i s e x t r e m e l y r a r e ( P l a t e V, f i g . 1 ) . C e l l d i v i s i o n i n c u l t u r e s o f b o t h s p e c i e s o f T r i p l o c e r a s o c c u r s e v e r y t h r e e t o f i v e d ays u s u a l l y d u r i n g t h e d a r k p e r i o d . The e a r l i e s t d i v i d i n g c e l l s a r e f o u n d about s i x h o u r s a f t e r t h e 37 b e g i n n i n g o f t h e d a r k p e r i o d b u t d i v i d i n g c e l l s may s t i l l be f o u n d a f t e r t h e l i g h t p e r i o d b e g i n s . A f t e r n u c l e a r d i v i s i o n and c y t o -k i n e s i s t h e s e m i c e l l s s e p a r a t e a t t h e i s t h m u s and a r e pushed a p a r t b y t h e e l o n g a t i n g new s e m i c e l l s ( P l a t e V, f i g . 2-7; P l a t e 7 1 , f i g . 1-U). As t h e new s e m i c e l l becomes l o n g e r t h e n u c l e u s m i g r a t e s i n t o t h e new s e m i c e l l and i s f o l l o w e d b y t h e e l o n g a t i n g c h l o r o p l a s t . The n u c l e u s s t o p s about 25 u f r o m t h e i s t h m u s and i s pushed t o t h e s i d e and o b s c u r e d b y t h e e l o n g a t i n g c h l o r o p l a s t . The young s e m i c e l l r e a c h e s i t s f i n a l l e n g t h b e f o r e a p i c a l l o b e s o r w a l l p r o t u b e r a n c e s a r e f o r m e d ( P l a t e V, f i g . 7; P l a t e 7 1 , f i g . 3 , U). The l a t e r a l m a r g i n s o f t h e new s e m i c e l l become u n d u l a t e and t h e n t h e c h a r a c t e r -i s t i c p r o t u b e r a n c e s a r e formed. The a p i c a l l o b e s f o r m and t h e i r s p i n a t e o r n a m e n t a t i o n i s p r o d u c e d ( P l a t e 7 1 , f i g . I i ) . E l o n g a t i o n o f t h e new s e m i c e l l l a s t s a p p r o x i m a t e l y 2 1/2 h o u r s . The c h l o r o -p l a s t t h e n d i v i d e s d u r i n g t h e f o l l o w i n g one o r two h o u r s and t h e n u c l e u s moves t o t h e i s t h m u s r e g i o n between t h e two c h l o r o p l a s t s . T h i s sequence o f e v e n t s o c c u r s i n c u l t u r e s o f b o t h s p e c i e s o f T r i -p l o c e r a s . M i t o t i c s t a g e s i n l i v i n g T r i p l o c e r a s c e l l s a r e d i f f i c u l t t o o b s e r v e as c h l o r o p l a s t l o b e s o b s c u r e t h e n u c l e u s . I n s t a i n e d c e l l s f i l a m e n t o u s chromosomes c a n sometimes be s e e n b u t a r e u s u a l l y o b s c u r e d b y a m a t r i x w h i c h t a k e s up t h e a c e t o c a r m i n e s t a i n ( P l a t e V I I I , f i g . 5 ) . Treatment o f t h e c e l l s w i t h one p e r c e n t c o l c h i c i n e makes t h e chromosomes more c o n s p i c u o u s . The c o l c h i c i n e t r e a t m e n t c a u s e s t e m p o r a r y d e l a y o f m i t o s i s i n l a t e p r o p h a s e o r metaphase b u t d i v i s i o n o f t h e n u c l e u s e v e n t u a l l y o c c u r s . Njo e v i d e n c e was 38 f o u n d t h a t c o l c h i c i n e had any e f f e c t on t h e p l o i d y l e v e l o f t h e n u c l e u s . C e l l s l e f t i n c o l c h i c i n e d i e d w i t h i n a week, h a v i n g undergone one o r a t most two d i v i s i o n s . The chromosomes o f T. v e r t i c i l l a t u m a r e l o n g and f i l a -mentous i n c e l l s t r e a t e d w i t h c o l c h i c i n e ( P l a t e I X , f i g . 1). The l o n g e s t chromosomes, measured i n l a t e p r o p h a s e , a r e a p p r o x i m a t e l y 20 JU i n l e n g t h and t h e s m a l l e s t a r e 2-3 fx. l o n g . S e v e r a l d a r k l y s t a i n e d r e g i o n s o c c u r on t h e chromosomes ( P l a t e I X , f i g . 3, 4 ) . The p a r a l l e l s e p a r a t i o n o f c h r o m a t i d s a t l a t e metaphase i n d i c a t e s t h a t t h e r e i s no l o c a l i z e d c e n t r o m e r e on t h e chromosomes ( P l a t e I X , f i g . 2 ) . Chromosome c o u n t s f o r T. v e r t i c i l l a t u m a r e n = l $ - 2 0 . The chromosomes o f T. g r a c i l e a l s o appear f i l a m e n t o u s b u t a r e s m a l l e r t h a n t h o s e o f T. v e r t i c i l l a t u m ( P l a t e V I I I , f i g . 3» U ) . S a t i s f a c t o r y p r e p a r a t i o n s o f T. g r a c i l e f o r chromosome c o u n t i n g were n o t o b t a i n e d . 39 C. D i s c u s s i o n . B o d i e s o f w a t e r a d j a c e n t t o Sphagnum bogs u s u a l l y have v e r y w e l l d e v e l o p e d d e s m i d f l o r a s ( P r e s c o t t 19U8). The f a c t t h a t T r i p l o -c e r a s w i l l n o t grow on a s o i l w a t e r medium b u t w i l l grow when a s m a l l amount o f p u l v e r i z e d p e a t i s added s u g g e s t s t h a t t h e p r e s e n c e o f Sphagnum may be an i m p o r t a n t f a c t o r i n t h e d i s t r i b u t i o n o f t h e genus. The e f f e c t o f t h e p u l v e r i z e d Sphagnum i s n o t due t o changes i n t h e pH o f t h e medium b e c a u s e t h e r e i s l i t t l e change i n pH when p e a t i s added t o t h e medium ( f r o m 6.0-6.5 t o 5.5-6.5). The f i n d i n g o f T r i - p l o c e r a s i n w a t e r o f pH 8.4 a l s o s u g g e s t s t h a t t h e a c i d i t y o f t h e w a t e r i s n o t n e c e s s a r y f o r g r o w t h o f T r i p l o c e r a s ( K r i e g e r 1937). The most p r o b a b l e e x p l a n a t i o n f o r t h e e f f e c t o f Sphagnum i s t h a t o r g a n i c c h e l a t o r s o f "humates" p r o d u c e d i n t h e bog a r e i m p o r t a n t i n m a i n t a i n i n g t h e a v a i l a b i l i t y o f n u t r i e n t i o n s . The a d d i t i o n o f e t h y l e n e d i a m i n e t e t r a a c e t i c a c i d (EDTA) t o c u l t u r e m e d i a i s a s t a n d a r d p r o c e d u r e f o r m a i n t a i n i n g t h e a v a i l a b i l i t y o f m i c r o n u t r i e n t s , e s p e -c i a l l y i r o n ( P r o v a s o l i & P i n t n e r I960). W a r i s (1953) f o u n d t h a t t h e d e s m i d M i c r a s t e r i a s grew b e t t e r i n m i n e r a l m e d i a w i t h added EDTA. A n o t h e r e x p l a n a t i o n w h i c h must be c o n s i d e r e d f o r t h e s t i m u l a t i n g e f f e c t o f Sphagnum p e a t i s t h a t i t may c o n t a i n a compound r e q u i r e d f o r g r o w t h o f T r i p l o c e r a s . Many a l g a e have b e e n f o u n d t o r e q u i r e v i t a m i n s i n o r d e r t o grow i n c u l t u r e ( P r o v a s o l i & P i n t n e r I960). A few d e s m i d s , s p e c i e s o f Cosmarium and M i c r a s t e r i a s , have been grown i n p u r e c u l t u r e w i t h o u t v i t a m i n s ( P r i n g s h e i m 1946). However, s u c h a r e q u i r e m e n t may e x i s t f o r o t h e r d e s m i d s , i n c l u d i n g T r i p l o c e r a s . uo Desmids have b e e n grouped i n t o t e n a s s o c i a t i o n s b y L a p o r t e ( 1 9 3 1 ) . Some o f t h e s e a s s o c i a t i o n s a r e d e f i n e d on t h e b a s i s o f h a b i t a t ( e . g . s u b a e r i a l d e s m i d s , b e n t h i c l a k e d e s m i d s , p l a n k t o n i c d e s m i d s , c a l c i p h i l i c d esmids) w h i l e o t h e r s a r e d e f i n e d b y t h e p r e s e n c e o f l a r g e q u a n t i t i e s o f c e r t a i n desmid g e n e r a ( e . g . C l o s -t e r i e t u m commune, E u a s t r e t o - M i c r a s t e r i e t u m , C o s m a r i e t u m - S t a u r a s -t r e t u m ) . Desmids f r o m t h e l a k e s i n t h i s s t u d y f i t i n t o t h e g e n e r a l i z e d a s s o c i a t i o n o f b e n t h i c desmids (Desmidiaceatum Benthicum) w h i c h i s c h a r a c t e r i s t i c o f t h e bo t t o m o f a c i d l a k e s . I t was r e c o g -n i z e d b y L a p o r t e t h a t t h i s a s s o c i a t i o n was p o o r l y d e f i n e d and p r o -b a b l y c o n s i s t e d o f s e v e r a l s e p a r a t e ones. The desmids s q u e e z e d f r o m mosses a t t h e edges o f t h e l a k e s , M i k e Lake and P l a c i d Lake i n p a r t i c u l a r , f i t i n t o t h e E u a s t r e t o - M i c r a s t e r i e t u m a s s o c i a t i o n d o m i n a t e d b y s p e c i e s o f Euast r u m and M i c r a s t e r i a s . These r e s u l t s a g r e e w i t h t h e o b s e r v a t i o n o f L a p o r t e t h a t t h i s a s s o c i a t i o n i s s p h a g n o p h i l i c . T r i p l o c e r a s i s a r a r e element i n b o t h t h e s e a s s o -c i a t i o n s , b u t i s more common among t h e b e n t h i c d e s m i d s . T h e r e does no t seem t o be any group o f s p e c i e s w i t h w h i c h T r i p l o c e r a s can be d e f i n i t e l y a s s o c i a t e d . S e v e r a l d e s m i d s , i n c l u d i n g T r i p l o c e r a s , a r e p r e s e n t i n c o l l e c t i o n s o n l y d u r i n g t h e summer months. The s e a s o n a l o c c u r r e n c e o f t h e s e desmids r a i s e s t h e q u e s t i o n o f what happens t o them i n t h e w i n t e r . Z y g o t e s o f desmids have n o t been seen i n any c o l l e c t i o n s f r o m t h e l a k e b o t t o m , a l t h o u g h z y g o t e s o f some s p e c i e s a r e common i n d r y i n g a r e a s o f t h e m a r g i n a l bogs d u r i n g t h e s p r i n g . A r e c e n t i n v e s t i g a t i o n s u g g e s t s t h a t desmids may be a b l e t o s u r v i v e f o r Ul l o n g p e r i o d s a t low t e m p e r a t u r e s w i t h o u t f o r m i n g r e s i s t a n t s t a g e s o r z y g o t e s ( D u t h i e 1°6U)» However, b e c a u s e no c e l l s o f T r i p l o c e r a s have b e e n f o u n d d u r i n g t h e w i n t e r and be c a u s e c e l l s a r e v e r y r a r e even i n t h e summer c o l l e c t i o n s t h e method o f o v e r w i n t e r i n g b y T r i p l o c e r a s r e m a i n s u n c e r t a i n . F o r m a t i o n o f ab n o r m a l c e l l s i n M i c r a s t e r i a s has been i n d u c e d e x p e r i m e n t a l l y b y t e m p e r a t u r e changes and b y c h e m i c a l t r e a t m e n t s ( K a l l i o 1951, W a r i s 1950, W a r i s & K a l l i o 1957). I t i s a l s o known t h a t u n f a v o u r a b l e c u l t u r e c o n d i t i o n s r e s u l t i n t h e spontaneous f o r m a t i o n o f ab n o r m a l c e l l s ( K a l l i o 1951). S i n c e t h e number o f abnormal c e l l s o f T r i p l o c e r a s i n c r e a s e s as t h e c u l t u r e ages t h e p r o d u c t i o n o f a b n o r m a l c e l l s may be due t o t h e h i g h c o n c e n t r a t i o n o f c e l l s w h i c h w o u l d r e s u l t i n t h e a c c u m u l a t i o n o f s u b s t a n c e s i n h i b i -t o r y t o n o r m a l c e l l d e v e l opment. The p r e s e n c e o f b a c t e r i a i n t h e c u l t u r e t u b e may a l s o b e d e t r i m e n t a l ( K a l l i o 1951) e s p e c i a l l y i n o l d e r c u l t u r e s where t h e p r o p o r t i o n o f b a c t e r i a i n c r e a s e s due t o t h e s l o w g r o w t h o f t h e de s m i d s . I n o l d c u l t u r e s o f T. g r a c i l e c e l l s become t r a p p e d i n a c c u m u l a t e d m u c i l a g e w h i c h may p r e v e n t c e l l s f r o m o b t a i n i n g s u f f i c i e n t n u t r i e n t s f o r n o r m a l development. B i n u c l e a t e c e l l s sometimes r e s u l t f r o m c e l l s t r a p p e d i n m u c i l a g e so t h a t c y t o k i n e s i s i s somehow d i s r u p t e d . The X-shaped c e l l s formed i n T. g r a c i l e c u l t u r e s a r e u n i q u e i n t h e D e s m i d i a c e a e . K a l l i o (1951) l i s t s s e v e r a l p o s s i b l e morpho-l o g i c a l t y p e s r e s u l t i n g from t h e f a i l u r e o f c y t o k i n e s i s i n M i c r a s - t e r i a s . I n no c a s e i s t h e r e t h e f o r m a t i o n o f e x t e n s i o n s o f t h e c e n t r a l r e g i o n o f t h e b i n u c l e a t e c e l l w h i c h a r e i d e n t i c a l i n fo r m 1*2 w i t h n o r m a l s e m i c e l l s . I n T. v e r t i c i l l a t u m , and i n some i n s t a n c e s w i t h T. g r a c i l e , b i n u c l e a t e c e l l s a r e formed w h i c h c o r r e s p o n d w i t h Type I o f K a l l i o ( 1 9 $ 1 ) . These c e l l s have a b u l b o u s c e n t r a l r e g i o n c o n n e c t i n g t h e o l d s e m i c e l l s and one n u c l e u s i n each i s t h m u s r e g i o n . As has b e e n n o t e d b y K a l l i o f o r M i c r a s t e r i a s , t h e e f f e c t o f two n u c l e i i n one c e l l o f T. g r a c i l e r e s u l t s i n an a p p r o x i m a t e d o u b l i n g o f t h e c y t o p l a s m i c volume o f t h e c e l l . The chromosomes o f T. v e r t i c i l l a t u m a r e t h e l a r g e s t y e t r e c o r d e d f o r t h e D e s m i d i a c e a e . K i n g (I960) r e p o r t e d t h a t t h e l a r g e s t chromosomes i n s p e c i e s examined b y him were U.5 jx l o n g (measured a t l a t e p r o p h a s e s t a g e ) . Up t o f i v e d a r x l y s t a i n i n g r e g i o n s were seen b y him on t h e l a r g e r chromosomes i n l a t e p r o p h a s e . The chromosomes o f T. v e r t i c i l l a t u m have s i m i l a r d a r k l y s t a i n i n g r e g i o n s on chromosomes i n d i c a t i n g t h a t c e r t a i n r e g i o n s o f t h e chromosomes a r e more condensed t h a n o t h e r s . I n a l i s t o f chromo-some numbers i n t h e D e s m i d i a c e a e ( K i n g I960) t h e l o w e s t numbers a r e n = c. 12 f o r H y a l o t h e c a d i s s i l i e n s and n = c. I i * f o r S t a u r a s t r u m  g r a c i l e and t h e h i g h e s t number i s 592 f o r N e t r i u m d i g i t u s . Most o f t h e chromosome numbers a r e between n = 12 and n = 60. T. v e r t i - c i l l a t u m ( n = 15-20) i s n e a r t h e l o w e r end o f t h i s r ange o f chromo-some numbers. The p a r a l l e l d i s j u n c t i o n o f c h r o m a t i d s a t l a t e meta-phase i n d i c a t e s t h a t t h e chromosomes o f T. v e r t i c i l l a t u m do n o t have a l o c a l i z e d c e n t r o m e r e . T h i s t y p e o f c e n t r o m e r i c o r g a n i z a t i o n i s c h a r a c t e r i s t i c o f many o f t h e Zygnemaceae and D e s m i d i a c e a e ( K i n g I960, Godward 19%). N i n e v a r i e t i e s o f T r i p l o c e r a s g r a c i l e were r e c o g n i z e d b y k3 K r i e g e r (1937), b u t o n l y two o f t h e s e , T. g r a c i l e v a r . b i d e n t a t u m and T. g r a c i l e v a r . d e n t i c u l a t u r n , have b e e n c o l l e c t e d more t h a n a few t i m e s . F i v e o f t h e n i n e v a r i e t i e s (T. g r a c i l e v a r . q u a d r i -l o b a t u m , v a r . montanum, v a r . e l e g a n s , v a r . l a t i c e p s , and v a r . robustum) have n o t b e e n c o l l e c t e d s i n c e t h e y were d e s c r i b e d . V a r i e t y t r i d e n t a t u m was c o l l e c t e d t w i c e f r o m A u s t r a l i a and New Z e a l a n d and v a r i e t y a c u l e a t u m was r e p o r t e d f o u r t i m e s f r o m A u s t r a l i a and New Z e a l a n d . V a r i e t y b i s p i n a t u m ( T a y l o r 193U), p l a c e d b y K r i e g e r u n d e r v a r i e t y b i d e n t a t u m , has been c o n s i d e r e d b y some l a t e r a u t h o r s t o be a d i s t i n c t v a r i e t y b e c a u s e o f d i f f e r e n c e s i n t h e m o r p h o l o g y o f t h e p r o t u b e r a n c e s ( I r e n e e - M a r i e 1952, S c o t t & G r o n b l a d 1957, G a u t h i e r - L i e v r e I 9 6 0 ) . Three a d d i t i o n a l v a r i e t i e s o f T. g r a c i l e have b e e n d e s c r i b e d r e c e n t l y f r o m A f r i c a . V a r i e t y sudanense ( G r o n b l a d , Prowse & S c o t t 1958) i s v e r y c l o s e t o v a r i e t y b i d e n t a t u m , h a v i n g f e w e r w h o r l s o f p r o t u b e r a n c e s (8-10) pe r s e m i c e l l and l o n g e r p r o t u b e r a n c e s . V a r i e t i e s t o r r i d a and a f r i c a n a were d e s c r i b e d f r o m S i e r r a Leone (Woodhead & Tweed 1959) b u t p o o r l y e x e c u t e d d r a w i n g s make i t i m p o s s i b l e t o compare t h e s e v a r i e t i e s w i t h o t h e r s . G a u t h i e r -L i e v r e ( I 9 6 0 ) c o n s i d e r e d T. g r a c i l e v a r . t o r r i d a a f o r m o f v a r i e t y d e n t i c u l a t u m and T. g r a c i l e v a r . a f r i c a n a a f o r m o f v a r i e t y b i d e n t a t u m . F i v e o f t h e v a r i e t i e s r e c o g n i z e d b y K r i e g e r a r e b a s e d on v a r i a t i o n s i n t h e s t r u c t u r e o f t h e p r o t u b e r a n c e s on t h e s e m i c e l l . The r e s u l t s o f t h e p r e s e n t i n v e s t i g a t i o n i n d i c a t e t h a t , a t l e a s t i n T. g r a c i l e v a r . g r a c i l e , t h e p r o t u b e r a n c e morphology i s c o n s t a n t . I t would appear t h a t d i f f e r e n c e s i n morphology of t h e protuberances are u s e f u l i n d e s c r i p t i o n o f T . g r a c i l e v a r i e t i e s , whether t h i s c o n c l u s i o n i s v a l i d w i l l have t o be conf irmed b y s t u d i e s on the v a r i a b i l i t y of those v a r i e t i e s h a v i n g m o r p h o l o g i c a l l y d i f f e r e n t p r o t u b e r a n c e s . The o t h e r f o u r v a r i e t i e s o f T . g r a c i l e r e c o g n i z e d b y K r i e g e r a r e based on d i f f e r e n c e s i n t h e s t r u c t u r e o f the s e m i c e l l apex. The p r e s e n t i n v e s t i g a t i o n has shown t h a t i n a s i n g l e c l o n e t h e apex may be b i r a d i a t e t o q u a d r i r a d i a t e . Thus t h e r a d i a t i o n o f t h e apex cannot be used as a taxonomic c r i t e r i o n i n T . g r a c i l e . V a r i e t y q u a d r i l o b a t urn , t h e r e f o r e , s h o u l d be i n c l u d e d i n the synonymy of T. g r a c i l e v a r . g r a c i l e . K r i e g e r (1937) l i s t s two v a r i e t i e s of T . v e r t i c i l l a t u m , v a r . superbum and v a r . t u r g i d u m , b o t h of which d i f f e r from T . v e r t i - c i l l a t u m v a s v e r t i c i l l a t u m i n t h e s t r u c t u r e o f t h e i r p r o t u b e r a n c e s . V a r i e t y turgescens ( S c o t t and Gronblad 1957) and v a r i e t y minor ( G a u t h i e r - L i e v r e I960) a l s o have c h a r a c t e r i s t i c d i f f e r e n c e s i n p r o -tuberance morphology. These d i f f e r e n c e s are p r o b a b l y constant , because v e r y l i t t l e v a r i a t i o n i n the shape o f protuberances was observed i n c u l t u r e s o f T . v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m used i n t h i s s t u d y . However, as s t a t e d f o r T . g r a c i l e , t h i s c o n c l u s i o n r e q u i r e s v e r i f i c a t i o n b y s i m i l a r s t u d i e s on s e v e r a l v a r i e t i e s of T . v e r t i c i l l a t u m . The presence of b i r a d i a t e and t r i r a d i a t e s e m i c e l l a p i c e s i n c l o n e s of T . v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m used i n t h i s s t u d y \6 i n d i c a t e s t h a t , as w i t h T. g r a c i l e , v a r i e t i e s b a s e d on v a r i a t i o n i n a p i c a l r a d i a t i o n must be abandoned. Such v a r i a t i o n must be c o n s i d e r e d as non-taxonomic ( G r o n b l a d and R u z i c k a 1959)• Thus T. v e r t i c i l l a t u m f o r m a t r i r a d i a t u m ( I r e n e e - M a r i e 1952) and T. v e r t i - c i l l a t u m v a r . t a y l o r i i ( S c o t t and G r o n b l a d 1957) c a n n o t be m a i n t a i n e d s i n c e t h e y a r e b a s e d on t h e p r e s e n c e o f t r i r a d i a t e a p i c e s on t h e s e m i c e l l s . k6 LITERATURE CITED ^ R e f e r e n c e n o t s e e n . I n f o r m a t i o n o b t a i n e d f r o m s o u r c e i n p a r e n -t h e s e s . Andrews, F. M. 1926. A l i s t o f a l g a e o f Monroe County, I n d i a n a . I I . P r o c . I n d i a n a Acad. S c i . 36:223-225. A r c h e r , W. 1865. O b s e r v a t i o n s on M i c r a s t e r i a s m a h a b u l e s h w a r e n s i s and D o c i d i u m p r i s t i d a e . Q u a r t . J . M i c . S c i . , n . s . , 5:255-262. • s f i a i l e y , F. M. 1898. C o n t r i b u t i o n s t o t h e Queensland f l o r a . I . Dept. A g r . Queensland B o t . B u l l . 15 ( i n K r i e g e r 1937). B a i l e y , J . W. 1851. M i c r o s c o p i c a l o b s e r v a t i o n s made i n S o u t h C a r o l i n a , G e o r g i a and F l o r i d a . S m i t h s o n i a n C o n t r i b . Knowl. 2(8):1-U8. B e h r e , K. 1956. D i e S u s s w a s s e r a l g e n d e r W a l l a c e a - E x p e d i t i o n . A r c h . H y d r o b i o l . 23(Suppl.):l-10iu •KBorge, 0. I896. A u s t r a l i s c h e S u s s w a s s e r c h l o r o p h y c e e n . B i h . Sv. V e t . - A k a d . H a n d l . 2k, A b t . I l l , H e f t 9:1-32 ( i n Moura and S i l v a 1938). •KBorgesen, F. 1890. D e s m i d i e a e i n E . Warming, Symbolae ad f l o r a m B r a s i l i a e c e n t r a l i s cognoscendam. V i d . Medd. n a t u r h . F o r e n . Kjobenhavn 1890:929-958 ( i n Moura and S i l v a 1938). • a B o u r r e l l y , P. 1957. A l g u e s d"eau douce du Soudan f r a n c a i s , r e g i o n du M a c i n a (A.O.F.). B u l l . I n s t . Fran<jais A f r . N o i r e 19 ( i n G a u t h i e r - L i e v r e I960). 47 Brown, H. J . 1930. The desmids o f t h e s o u t h e a s t e r n c o a s t a l p l a i n r e g i o n o f t h e U n i t e d S t a t e s . T r a n s . Amer. M i c . S o c . 49: 97-139. C a r t e r , N. 1935. A l p i n e desmids f r o m B r i t i s h C o l u m b i a . J . L i n n . Soc. B o t . London 50:151-174. Crow, W. B. 1923. F r e s h w a t e r p l a n k t o n a l g a e f r o m C e y l o n . J . B o t . London 61:164-171. Cushman, J . A. 1905. Desmid f l o r a o f New Hampshire. R h odora 7:111-118. D u t h i e , H. C. 1961*. The s u r v i v a l o f desmids i n i c e . B r i t . P h y c o l . B u l l . 2:376-377. E l f v i n g , F. 1881. A n t e c k n i n g a r om F i n s k a D e s m i d i e e r . A c t a Soc. Fauna F l o r a Fenn. 2(2):1-17. F r i t s c h , F. E. 1907. A g e n e r a l c o n s i d e r a t i o n o f t h e s u b a e r i a l and f r e s h w a t e r f l o r a o f C e y l o n . A c o n t r i b u t i o n t o t h e s t u d y o f t r o p i c a l a l g a l e c o l o g y . I . S u b a e r i a l a l g a e and a l g a e o f i n l a n d f r e s h w a t e r s . P r o c . Roy. Soc. London, B, 79:197-254. G a u t h i e r - L i e v r e , L. I960. Les genr e s I c h t h y o c e r c u s , T r i p l o c e r a s e t T r i p l a s t r u m en A f r i q u e . Rev. A l g o l . , n . s . , 5:55-65. Godward, M. B. E. 1954. D i f f u s e c e n t r o m e r e o r p o l y c e n t r i c chromosomes i n S p i r o g y r a . Ann. B o t . , n . s . , 18;143-156. G r o n b l a d , R. 1920. F i n n l a n d i s c h e D e s m i d i a c e e n aus Keu r u . A c t a S o c . Fauna F l o r a Fenn. 47(4):l -98. G r o n b l a d , R. 1936. Desmids f r o m N o r t h R u s s i a ( K a r e l i a ) c o l l e c t e d 1918 a t U h t u a ( U k h t i n s k a y a ) and H i r v i s a l m i . S o c . S c i . Fenn., Comm. B i o l . 5(6):1-12. U8 G r o n b l a d , R. 1945. De a l g i s b r a s i l i e n s i b u s . A c t a Soc. S c i . F e n n . , n . s . , B, 2(6): 1-1(3. G r o n b l a d , R. 1956. Desmids f r o m t h e U n i t e d S t a t e s , c o l l e c t e d i n 1947-1949 b y Dr. Hannah C r o a s d a l e and D r . E d w i n T. M o u l . S o c . S c i . F enn., Comm. B i o l . 15(12):l-38. G r o n b l a d , R., Prowse, G. A., and S c o t t , A. M. 1958. Sudanese d e s m i d s . A c t a B o t . Fenn. 58:1-82. G r o n b l a d , R. and R u z i c k a , J . 1959. Z u r S y s t e m a t i k d e r D e s m i d i a c e e n . B o t . Not. 112:205-226. G r o n b l a d , R. and S c o t t , A. M. 1955. On t h e v a r i a t i o n o f S t a u r a s - t r u m b i b r a c h i a t u m R e i n s c h as an example o f v a r i a b i l i t y i n a desmid s p e c i e s . A c t a Soc. Fauna F l o r a Fenn. 72(6):1-11. • a G u t w i n s k i , R. 1902. De a l g i s a M. R a c i b o r s k i anno 1899 i n I n s u l a J a v a c o l l e c t i s . B u l l . Acad. S c i . C r a c o v i e , C l . math, n a t . , 1902 ( i n K r i e g e r 1937). H i m , K. E. 1903. Z u r K e n n t n i s d e r D e s m i d i a c e e n F i n n l a n d s . A c t a S o c . Fauna F l o r a Fenn. 25(3) : l - 2 l i . Hobson, J . 1863. Notes on I n d i a n D e s m i d i e a e . Q u a r t . J . M i c . S c i . , n . s . , 3:168-170. Hughes, E. 0. 1950. F r e s h - w a t e r a l g a e o f t h e m a r i t i m e p r o v i n c e s . P r o c . Nova S c o t i a n I n s t . S c i . 22(2):1-63. H y l a n d e r , C. J . 1928. The a l g a e o f C o n n e c t i c u t . C o n n e c t i c u t G e o l . N a t . H i s t . S u r v . B u l l . 42:1-245. •HTrenee-Marie, F r . 1938. F l o r e d e s m i d i a l e de l a r e g i o n de M o n t r e a l . L a p r a i r i e , M o n t r e a l . 547 pp. ( i n I r e n e e - M a r i e , 1952). 49 I r e n e e - M a r i e , F r . 1952. C o n t r i b u t i o n a l a c o n n a i s s a n c e d e s Des m i d i e e s de l a r e g i o n du Lac S t . - J e a n . H y d r o b i o l o g i a 4:1-208. I r e n e e - M a r i e , F r . 1959a. C o n t r i b u t i o n a l a c o n n a i s s a n c e des De s m i d i e e s du s u d - e s t de l a P r o v i n c e de Quebec eft de l a G a s p e s i e . H y d r o b i o l o g i a 12:107-128. I r e n e e - M a r i e , F r . 1959b. E x p e d i t i o n a l g o l o g i q u e dans l e n o r d de l a M a u r i c i e , b a s s i n de l a M a t t a w i n . H y d r o b i o l o g i a 13: 319-381. I r e n e e - M a r i e , F r . and H i l l i a r d , D. K. 1963. Desmids f r o m s o u t h c e n t r a l A l a s k a . H y d r o b i o l o g i a 21:90-124. ^-Iyengar, M. and Ramanathan, K. 1942. T r i p l a s t r u m , a new member o f t h e D e s m i d i a c e a e f r o m S o u t h I n d i a . J . I n d i a n B o t . S o c . 21 ( i n G a u t h i e r - L i e v r e , I960). K a l l i o , P. 1951. The s i g n i f i c a n c e o f n u c l e a r q u a n t i t y i n t h e genus M i c r a s t e r i a s . S o c . Z o o l . B o t . Fenn. 'Vanamo 1, Ann. B o t . 24(2):1-120. K i n g , G. C. I960. The c y t o l o g y o f t h e d e s m i d s : t h e chromosomes. New P h y t o l . 59:65-72. K o s s i n s k a y a , E. K. I960. F l o r a p l a n t a r u m cryptogamarura U.R.S.S. V o l . 5 C o n j u g a t a e 2. 706 pp. K r i e g e r , W. 1932. D i e D e s m i d i a c e e d e r De u t s c h e n l i m n o l o g i s c h e n S u n d a - E x p e d i t i o n . A r c h . H y d r o b i o l . l l ( S u p p l . ) : 1 2 9 - 2 3 0 . K r i e g e r , W. 1937. D i e D e s m i d i a c e e n E u r o p a s , m i t B e r u c k s i c h t i g u n g d e r A u s s e r e u r o p a i s c h e n A r t e n . I n L. R a b e n h o r s t K r y p t o -g a m e n f l o r a 13(1) 712pp. 50 L a p o r t e , L. J . 1931. R e c h e r c h e s s u r l a b i o l o g i e e t l a s y s t e m -a t i q u e des D e s m i d i e e s . E n c y c l . B o t . 9s1-150. # L u n d e l l , P. 18?1. De D e s r a i d i a c e i s quae i n S u e c i a i n v e n t a e s u n t o b s e r v a t i o n e s c r i t i c a e . Nova A c t a Reg. Soc. S c i . U p s a l a , S e r . 3, 8:1-100 ( i n Moura and S i l v a 1938). M a s k e l l , W. M. 1880. New Z e a l a n d D e s m i d i e a e . T r a n s . New Z e a l a n d I n s t . 13:297-317. M a s k e l l , W. M. 1882. On t h e New Z e a l a n d D e s m i d i e a e . A d d i t i o n s t o c a t a l o g u e and n o t e s on v a r i o u s s p e c i e s . T r a n s . P r o c . New Z e a l a n d I n s t . 15:237-259. M a s k e l l , W. M. 1885. On a new v a r i e t y o f d e s m i d . T r a n s . P r o c . New Z e a l a n d I n s t . 18:325. M a s k e l l , ¥. M, 1888. F u r t h e r n o t e s on t h e D e s m i d i e a e on New Z e a l a n d , w i t h d e s c r i p t i o n s o f new s p e c i e s . T r a n s . P r o c . New Z e a l a n d I n s t . 21:3-32. •aMoebius, M. 1892. A u s t r a l i s c h e S u s s w a s s e r a l g e n . F l o r a 1892 ( i n Moura and S i l v a 1938). Moura, L. and S i l v a , J . 1938. C o n t r i b u i c a o a d i s t r i b u i c a o g e o g r a f i c a do genero T r i p l o c e r a s . R e u n i a o Sul-Amer. B o t . , A n a i s , 2:233-21*0. # N o r d s t e d t , 0. 1877. N o n n u l l a e a l g a e aquae d u l c i s b r a s i l i e n s i s . O f v e r s . K. Sv. V e t . Akad. F o r h . I877 (3) ( i n Moura and S i l v a 1938). N o r d s t e d t , 0. 1888. F r e s h w a t e r a l g a e , c o l l e c t e d b y D r . S. B e r g g r e n i n New Z e a l a n d and A u s t r a l i a . K. Sv. V e t . Akad. H a n d l . 22(8):l-96. 51 P l a y f a i r , G. 1907. Some new o r l e s s known desmids f o u n d i n New S o u t h W a l e s . P r o c . L i n n . S o c . New S o u t h Wales 32:160-201. P l a y f a i r , G. 1910. Po l y m o r p h i s m and l i f e h i s t o r y i n t h e De s m i d i a c e a e . P r o c . L i n n . Soc. New S o u t h Wales 35?U59-495» P r e s c o t t , G. W. 1948. Desmids. B o t . Rev. 14:6^4-676. P r e s c o t t , G. W. 1962. A l g a e o f t h e w e s t e r n G r e a t Lakes A r e a . R e v i s e d E d . , Wm. C. Brown, Dubuque, Iowa. 977 pp. P r e s c o t t , G. W. and S c o t t , A. M. 1942. The f r e s h w a t e r a l g a e o f s o u t h e a s t e r n U n i t e d S t a t e s . I . Desmids f r o m M i s s i s s i p p i , w i t h d e s c r i p t i o n s o f new s p e c i e s and v a r i e t i e s . T r a n s . Amer. M i c . S o c . 61:1-29. P r e s c o t t , G. W. and S c o t t , A. M. 1952. Some S o u t h A u s t r a l i a n d e s m i d s . T r a n s . Roy. Soc. S o u t h A u s t r a l i a 75:55-69. P r i n g s h e i m , E. G. 1946. P u r e c u l t u r e s o f a l g a e . Cambridge U n i v . P r e s s , London. 119 pp. P r o v a s o l i , L. and P i n t n e r , I . J . I 9 6 0 . A r t i f i c i a l m e d i a f o r f r e s h - w a t e r a l g a e : p r o b l e m s and s u g g e s t i o n s . Pymatuning Symp. K c o l o g y 2:84-96. R a l f s , J . I8I48. The B r i t i s h D e s m i d i e a e . Ray S o c i e t y , London. 226 pp. * R o l l , Y. V. 1923. Novye v i d i i f o r m i d e s m i d i e v y k h v o d o r o s l e i , naydennye v A r k h a n g e l • s k o y i O l o n e t s k o y gyb. B o t . M a t e r i a l y S p o r . R a s t . G l a v n . B o t . Sada R.S.F.S.R. 2:36-46 ( i n K o s s i n s k a y a I 9 6 0 ) . •KRoll, Y. V. 1927. M a t e r i a l y k f l o r e v o d o r o s l e i SSSR. Rody P l e u r o t a e n i u m Nag., Do c i d i u m (Breb.) Lund i T r i p l o c e r a s 52 B a i l . Nauk. Zapad. K h a r k i v s k . N a u k o v o - d o c l i d c h . K a t e d . B o t . 1:57-71 ( i n K o s s i n s k a y a I 9 6 0 ) . S a u n d e r s , D. A. 1901. The a l g a e o f t h e H a r r i m a n A l a s k a e x p e d i t i o n . P r o c . W a s h i n g t o n Acad. S c i . 3:391-1*86. Schumacher, G. 1958. An u n u s u a l a l g a l h a b i t a t . J . E l i s h a M i t c h e l l S c i . Soc. 7 U:lUl - l u 2 . S c o t t , A. M. and G r o n b l a d , R. 1957. New and i n t e r e s t i n g desmids f r o m t h e s o u t h e a s t e r n U n i t e d S t a t e s . A c t a Soc. S c i . Fenn., n . s . , B, 2(8):l-62. S c o t t , A. M. and P r e s c o t t , G. W. 1958. Some f r e s h w a t e r a l g a e f r o m Arnhem Land i n t h e N o r t h e r n T e r r i t o r y o f A u s t r a l i a . Rec. Amer.-Austr. S c i . E x p e d i t i o n Arnhem Land 3:9-136. S c o t t , A. M. and p r e s c o t t , G. W. 1961. I n d o n e s i a n d e s m i d s . H y d r o b i o l o g i a 17:1-132. S k u j a , H. 1949. Zur S u s s w a s s e r a l g e n f l o r a Burmas. Nova A c t a Reg. Soc. S c i . U p s a l a , S e r . 1*, lU ( 5 ):l - l 8 8 . S m i t h , G. M. 1921. The p h y t o p l a n k t o n o f t h e Muskoka r e g i o n , O n t a r i o , Canada. T r a n s . W i s c o n s i n Acad. S c i . A r t s L e t t . 20:323-361*. S m i t h , G. M. 1921*. P h y t o p l a n k t o n o f t h e i n l a n d l a k e s o f W i s c o n s i n . W i s c o n s i n G e o l . N a t . H i s t . S u r v . 57(2):1-227. T a y l o r , w. R. 193U. The f r e s h w a t e r a l g a e o f Newfoundland. I . Pa p e r s M i c h i g a n Acad. A r t s , S c i . L e t t . 19:217-280. T e i l i n g , E. 1950. R a d i a t i o n o f d e s m i d s , i t s o r i g i n and consequences as r e g a r d s taxonomy and n o m e n c l a t u r e . B o t . N o t. 1950:299-327. 53 T u r n e r , W. B. 1892. A l g a e aquae d u l c i s I n d i a e o r i e n t a l i s . K. Sv. V e t . Akad. H a n d l . 25(5):1-18?. V a a s , K. F. and S a c h l a n , M. 1948. On t h e e c o l o g y o f some s m a l l l a k e s n e a r B u i t e n z o r g , J a v a . H y d r o b i o l o g i a 1:238-250. W a i l e s , G. H. 1925. D e s m i d i e a e f r o m B r i t i s h C o l u m b i a . C o n t r i b . Can. B i o l . , n . s . , 2(21) : 1-12. W a i l e s , G. H. 1930a. Some a l g a e and p r o t o z o a f r o m Como Lake. Museum A r t N o t e s , V a n c o u v e r , B r i t i s h Columbia { 5:26-27. W a i l e s , G. H. 1930b. Munday Lake and i t s e c o l o g y . Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 5:92-109. W a i l e s , G. H. 1930c. P r o t o z o a and a l g a e , Mount F e r g u s o n , B. C. Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 5:160-165. W a i l e s , G. H. 1931a. Munday Lake and i t s e c o l o g y . I I . Museum A r t N o t e s , Vancouver, B r i t i s h C o l u m b i a . 6:34-37. W a i l e s , G. H. 1931b. P r o t o z o a and a l g a e , Mount F e r g u s o n , B. C. I I . Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 6:72-75. W a i l e s , G. H. 1931c. E c o l o g y o f S p r o a t Lake, B. C. Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 6:125-133. W a i l e s , G. H. 1932. P r o t o z o a and a l g a e f r o m Lake T e n q u i l l e , B. C. Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 7:19-23. W a i l e s , G. H. 1933. P r o t o z o a and a l g a e from Mount H o p e l e s s , B. C. Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 7 ( S u p p l . 7 ) : 1-4. w a i l e s , G. H. and T i f f a n y , L. H. 1929. Some a l g a e f r o m B r i t i s h C o l u m b i a . Museum A r t N o t e s , V a n c o u v e r , B r i t i s h C o l u m b i a . 4:171-177. 5U W a r i s , H. 1950. C y t o p h y s i o l o g i c a l s t u d i e s on M i c r a s t e r i a s . I I . The c y t o p l a s m i c framework and i t s m u t a t i o n . P h y s i o l . P l a n t . 3:236-21*6. W a r i s , H. 1953. The s i g n i f i c a n c e f o r a l g a e o f c h e l a t i n g s u b s t a n c e s i n t h e n u t r i e n t s o l u t i o n . P h y s i o l . P l a n t . 6:538-5U3» W a r i s , H. and K a l l i o , P. 1957. M o r p h o g e n e t i c e f f e c t s o f c h e m i c a l a g e n t s and n u c l e o p l a m i c r e l a t i o n s i n M i c r a s t e r i a s . Ann. Acad. S c i . Fenn., A, I V , 37:1-16. West, G. S. 1909. The a l g a e o f t h e Yan Yean R e s e r v o i r , V i c t o r i a : a b i o l o g i c a l and e c o l o g i c a l s t u d y . J . L i n n . S o c . B o t . London, 39:1-88. West, W. and West, G. S. I896. On some N o r t h A m e r i c a n D e s m i d i e a e . T r a n s . L i n n . S o c . B o t . London, n . s . , 5:2:29-271*. West, W. and West, G. S. 1902. A c o n t r i b u t i o n t o t h e f r e s h w a t e r a l g a e o f C e y l o n . T r a n s . L i n n . Soc. B o t . London, n . s . , 6:123-216. West, W. and West, G. S. 1901*, 1905, 1908, 1912. A monograph o f t h e B r i t i s h D e s m i d i e a e . V o l s . I - I V . Ray S o c i e t y , London. West, W., West, G. S., and C a r t e r , N. 1923. A monograph o f t h e B r i t i s h D e s m i d i e a e . V o l . V. Ray S o c i e t y , London. W h i t f o r d , L. 1958. P h y t o p l a n k t o n i n N o r t h C a r o l i n a l a k e s and ponds. J . E l i s h a M i t c h e l l S c i . Soc. 7U:ll*3-l57. * W i t t r o c k , V. B. 1869. A n t e c k n i n g a r om S k a n d i n a v i e n s D e s m i d i e e r . Nova A c t a Reg. S o c. U p s a l a 3(7) ( i n Moura and S i l v a 1938). * W o l l e , F. 1892. Desmids o f t h e U n i t e d S t a t e s . B e t h l e h e m , P e n n s y l v a n i a ( i n K r i e g e r 1937). 55 Wood, H. .0. 18?1|. A c o n t r i b u t i o n t o t h e h i s t o r y o f t h e f r e s h w a t e r a l g a e o f N o r t h A m e r i c a . S m i t h s o n i a n C o n t r i b . Khowl. 19(2ul):1-262. Woodhead, N. and Tweed, R. D. 1959. F r e s h w a t e r a l g a e o f S i e r r a Leone. I . New and u n u s u a l a l g a e f r o m t h e S u l a H i l l s . H y d r o b i o l o g i a 12:181-225. P l a t e I . Map showing l a k e s i n v e s t i g a t e d n e a r Haney, B r i t i s h C o l u m b i a a p p r o x i m a t e l y UO m i l e s e a s t o f Vancouver. NORTH ALOUETTE RIVER SOUTH ALOUETTE RIVER P l a t e I I . P h o t o g r a p h s o f C o l l e c t i o n a r e a s a t Gwendoline Lake and P l a c i d Lake. a. S o u t h s i d e o f Gwendoline Lake. June 1°6U. b. S o u t h s i d e o f P l a c i d Lake. June 1°6U. c. P o o l i n m a r g i n a l bog o f P l a c i d Lake f r o m w h i c h c o l l e c t i o n s were t a k e n . June 196U. 59 60 P l a t e I I I . Drawings o f v a r i e t i e s o f T r i p l o c e r a s and r e l a t e d d e s m i d s . 1. D o c i d i u m u n d u l a t u m v a r . b i s a n n i c u m , f r o m P l a c i d Lake. S c a l e C. 2. P l e u r o t a e n i u m e h r e n b e r g i i , f r o m P l a c i d Lake. S c a l e C. 3. T r i p l o c e r a s g r a c i l e v a r . montanum, a f t e r K r i e g e r . S c a l e B. i i . T. g r a c i l e v a r . a c u l e a t u m , a f t e r K r i e g e r . S c a l e B. 5>. T. g r a c i l e v a r . e l e g a n s , a f t e r K r i e g e r . S c a l e B. 6. T. g r a c i l e v a r . l a t i c e p s , a f t e r K r i e g e r . S c a l e B. 7. T. g r a c i l e v a r . t r i d e n t a t u r n , a f t e r K r i e g e r . S c a l e B. 8. T. g r a c i l e v a r . r o b u s t u m , a f t e r K r i e g e r . S c a l e B. 9. T. g r a c i l e v a r . q u a d r i l o b a t u m , a f t e r K r i e g e r . S c a l e B. 10. T. g r a c i l e v a r . b i d e n t a t u m , a f t e r K r i e g e r . S c a l e B. 11. T. g r a c i l e v a r . d e n t i c u l a t u m , a f t e r K r i e g e r . S c a l e B. 12. T. v e r t i c i l l a t u m v a r . superbum, a f t e r K r i e g e r . S c a l e A. 13. T. v e r t i c i l l a t u m v a r . t u r g i d u m , a f t e r K r i e g e r . S c a l e A. I i i . P l e u r o t a e n i u m a u s t r a l i a n u m , a f t e r K r i e g e r . S c a l e A. S c a l e s A, B, C, each 100 u. 19 62 P l a t e IV. Camera l u c i d a d r a w i n g s o f T r i p l o c e r a s . 1. T. g r a c i l e v a r . g r a c i l e , s e m i c e l l f r o m f i e l d c o l l e c t i o n . 2. T. g r a c i l e v a r . b i d e n t a t u m , s e m i c e l l f r o m f i e l d c o l l e c t i o n . 3 . T. g r a c i l e v a r . g r a c i l e , b i n u c l e a t e abnormal f o r m f r o m c u l t u r e . k> T. g r a c i l e v a r . g r a c i l e , a bnormal c e l l f rom c u l t u r e . B o t h s e m i c e l l s a r e s h o r t e n e d and one i s b i f u r c a t e . 5. T. g r a c i l e v a r . g r a c i l e , s e m i c e l l w i t h t r i r a d i a t e apex f r o m c u l t u r e . 6. T. g r a c i l e v a r . g r a c i l e , a b n o r mal f o r m i n c u l t u r e w i t h e x t r a p r o t u b e r a n c e s n e a r apex o f s e m i c e l l . 7. T. g r a c i l e v a r . g r a c i l e , t r i r a d i a t e apex ( l a t e r a l v i e w ) f r o m c e l l i n c u l t u r e . 8. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , t r i r a d i a t e apex ( l a t e r a l v i e w ) f r o m c e l l i n c u l t u r e . 99 1°. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , abnormal s e m i c e l l s i n c u l t u r e w i t h s w o l l e n b a s a l r e g i o n s and i r r e g u l a r arrangement o f p r o t u b e r a n c e s i n t h i s r e g i o n . 11. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , t r i r a d i a t e apex ( l a t e r a l v i e w ) f r o m c e l l i n c u l t u r e . One l o b e i s t i p p e d w i t h two s p i n e s and t h e o t h e r s a r e t i p p e d w i t h one s p i n e . S c a l e = 100 fi P l a t e V. Camera l u c i d a d r a w i n g s of T r i p l o c e r a s i n c u l t u r e . 1 . T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , b i n u c l e a t e abnormal f o r m f r o m o l d c u l t u r e . 2 . - 7 . T. g r a c i l e v a r . g r a c i l e , s t a g e s i n e l o n g a t i o n o f young s e m i c e l l a f t e r c e l l d i v i s i o n . The t i m e i n t e r v a l between s u c c e s s i v e i l l u s t r a t i o n s i s about 2 0 m i n u t e s . 8 . T. g r a c i l e v a r . g r a c i l e , b i n u c l e a t e abnormal f o r m f r o m c u l t u r e . 9. T. g r a c i l e v a r . g r a c i l e , b i r a d i a t e apex, l a t e r a l and a p i c a l v i e w s . 1 0 . T. g r a c i l e v a r . g r a c i l e , t r i r a d i a t e apex v i e w e d f r o m apex. 1 1 . T. g r a c i l e v a r . g r a c i l e , q u a d r i r a d i a t e apex v i e w e d f r o m apex. 1 2 . T. g r a c i l e v a r . g r a c i l e , b a s a l r i n g o f p r o t u b e r a n c e s on s e m i c e l l v i e w e d f r o m i s t h m u s . 1 3 . T. g r a c i l e v a r . g r a c i l e , t r i r a d i a t e apex, l a t e r a l v i e w . Ik. T. g r a c i l e v a r . g r a c i l e , q u a d r i r a d i a t e apex, l a t e r a l v i e w . 1 $ . T. g r a c i l e v a r . g r a c i l e , a p i c a l p o r t i o n o f s e m i c e l l S h o w i n g e x t r a p r o t u b e r a n c e s n o t i n t h e r e g u l a r w h o r l s o f p r o t u b e r a n c e s . 1 6 . T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , t r i r a d i a t e apex, a p i c a l v i e w . 1 7 . T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , a p i c a l r i n g o f p r o t u b e r a n c e s on s e m i c e l l as v i e w e d f r o m t h e apex. S c a l e = 1 0 0 u 66 P l a t e V I . Camera l u c i d a d r a w i n g s o f T r i p l o c e r a s v e r t i c i l l a t u m i n c u l t u r e . l . - U . T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , s t a g e s i n e l o n g a t i o n o f young s e m i c e l l a f t e r c e l l d i v i s i o n . $. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , c e l l i n c u l t u r e w i t h one b i r a d i a t e and one t r i r a d i a t e apex. 6. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , c e l l w i t h e x t r a p r o t u b e r a n c e s i n w h o r l s o f upper s e m i c e l l and w i t h p r o t u b e r a n c e s l a c k i n g i n t h r e e w h o r l s o f t h e l o w e r s e m i c e l l . 7. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , abnormal c e l l f r o m c u l t u r e . The b a s e o f t h e s e m i c e l l i s t w i s t e d and t h e arrangement o f p r o t u b e r a n c e s i s i r r e g u l a r . 8. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , b i n u c l e a t e abnormal c e l l f r o m o l d c u l t u r e . O r n a m e n t a t i o n on t h e p a r e n t a l s e m i c e l l s i s n o t f u l l y d e v e l o p e d . 9. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , b i r a d i a t e apex v i e w e d f r o m apex. S c a l e = 100 u 68 Plate VII. Photographs of T r i p l o c e r a s v e r t i c i l l a t u m and Pleurotaenium spinulosum. 1. T. v e r t i c i l l a t u m var. v e r t i c i l l a t u m , c e l l from lake c o l l e c t i o n with one b i r a d i a t e and one t r i r a d i a t e apex. (x210) 2. T. v e r t i c i l l a t u m var. v e r t i c i l l a t u m , abnormal c e l l from cul t u r e . One s e m i c e l l i s swollen and unornamented. (x320) 3. T. v e r t i c i l l a t u m var. v e r t i c i l l a t u m , abnormal c e l l from cul t u r e . One s e m i c e l l i s very short. (x320); U. T. v e r t i c i l l a t u m var. v e r t i c i l l a t u m , c e l l showing normal morphology i n c u l t u r e . (x280) 5. Pleurotaenium spinulosum, from cul t u r e . (x300) 6 9 70 Plate VIII. Photographs of Triploceras in culture. 1. T. gracile var. gracile, abnormal cell with one semicell bifurcate. (x280) 2. T. gracile var. gracile, abnormal cell with greatly-shortened semicell. (x320) 3. T. gracile var. gracile, stained preparation showing nucleus in anaphase (arrow). (xS>U0) U. T. gracile var. gracile, stained nucleus in meta-phase showing several chromosomes. (x890) 5. T* verticillatum var. verticillatum, metaphase in unsquashed cell not treated with colchicine. (xltfO) 71 72 P l a t e I X . P h o t o g r a p h s o f chromosomes o f T r i p l o c e r a s v e r t i c i l l a t u m . 1. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , l a t e p r o p h a s e s q u a s h . (x800) 2. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , l a t e metaphase squash showing p a r a l l e l s e p a r a t i o n o f c h r o m a t i d s i n d i c a t i v e o f d i f f u s e c e n t r o m e r e . (x2000) 3. U. T. v e r t i c i l l a t u m v a r . v e r t i c i l l a t u m , p o r t i o n s o f t h e p r e p a r a t i o n i n f i g . 1 a t h i g h e r m a g n i f i -c a t i o n showing b a n d i n g on chromosomes. (x2000) 73 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0105285/manifest

Comment

Related Items