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Contributions to the life history and ecology of the marine brown alga Phaeostrophion irregulare S. et… Mathieson, Arthur Curtis 1965

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The University of B r i t i s h Columbia FACULTY OF GRADUATE STUDIES PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY ARTHUR CURTIS MATHIESON B.A., University of C a l i f o r n i a , Los Angeles, 1959 M„A„, University of C a l i f o r n i a , Los Angeles, 1961 FRIDAY, MARCH 26, 1965, at 3:00 P.M. IN ROOM 3332, BIOLOGICAL SCIENCES BUILDING COMMITTEE IN CHARGE Chairman: I. McT. Cowan External Examiner: Michael Neushul. Department of B i o l o g i c a l Sciences University of C a l i f o r n i a Santa Barbara, C a l i f o r n i a of Kathleen Cole G„ L. Pickard G. .E. Rouse R„ F. Scagel W. B. Schofield E„ Bo Tregunna G. H. N. Towers CONTRIBUTIONS TO THE LIFE HISTORY AND ECOLOGY OF THE MARINE BROWN ALGA PHAEOSTROPHION IRBEGULARE S. et G, ON THE PACIFIC COAST OF NORTH AMERICA ABSTRACT U n t i l recently, few c o l l e c t i o n s of the marine brown alga Phaeostrophion i r r e g u l a r e S. et G. had been made, l i t t l e was known of i t s ecology, and v i r t u a l l y nothing of i t s l i f e h i s t o r y . The main objectives of t h i s investiga-t i o n were to study the l i f e h i s t o r y and major factors i n -fluencing growth and d i s t r i b u t i o n of t h i s species. Laboratory and f i e l d i nvestigations were conducted during 1961-64. L i f e h i s t o r y studies were performed i n the laboratory by c u l t u r i n g zoospores under constant environmental conditions. The growth of cultured germ-li n g s and the photosynthetic response of the laminate plants from, the f i e l d were recorded under d i f f e r e n t tem-peratures, s a l i n i t i e s , nutrients, and l i g h t conditions. The tolerance of laminate plants and germlings to extremes of temperature, s a l i n i t y , and desiccation was also deter-mined i n the laboratory. The growth and reproduction of i n s i t u plants at G l a c i e r Point, B r i t i s h Columbia was correlated with temperature, s a l i n i t y , nutrients, tides, sand and various meteorological conditions at that l o c a l i t y . L i f e h i s t o r y studies were conducted at Gla c i e r Point: by observing the succession of germlings on denuded transects and by transplanting laboratory cultured germlings into the f i e l d . The laminate t h a l l u s of P. i r r e g u l a r e sometimes bears both u n i l o c u l a r and pluril.ocular sporangia at; the same time. Previously, only u n i l o c u l a r sporangia were reported i n t h i s plant. Unispores and plurispores develop iden-t i c a l l y and each, i s capable of producing a laminate t h a l l u s d i r e c t l y or a f t e r a succession of filamentous and di s c o i d plethysmothalli. The "direct - t y p e " of development of the zoospores (unispores) from the u n i l o c u l a r sporan-gium i s probably due to a suppression of meiosis i n the un i l o c u l a r sporangium. Morphological and c u l t u r a l evidence i s presented to support t h i s hypothesis, although no cyto-l o g i c a l evidence was obtained. At G l a c i e r Point, P. i r r e g u l a r e i s r e s t r i c t e d to sandy areas, and the greatest number of plants occur where large f l u c t u a t i o n s of sand occur annually. The plants are r e g u l a r l y buried four to s i x months per year, and t h e i r growth and reproduction i s l i m i t e d to the period when sand i s absent. Competition with other plants pro-bably accounts for the occurrence of P. i r r e g u l a r e i n sandy areas, since i t w i l l grow i n rocky areas i f other algae are eliminated, The period of maximum growth (February to A p r i l ) i s associated with a corresponding increase i n l i g h t i n t e n s i t y and water temperature i n t h i s area. A f t e r A p r i l , growth i n non-tide pool populations decreases much more r a p i d l y than growth of t i d e pool pop-ulations, because of the increased exposure of plants to desiccation during daylight. A period of decreased growth for t i d e pool plants occurs i n May to June; t h i s decrease probably r e s u l t s from high surface water tempera-tures, high l i g h t i n t e n s i t i e s , or a combination of both. The morphology of the laminate plants of P. irregu-l a r e is.extremely v a r i a b l e and the range of v a r i a b i l i t y observed at. G l a c i e r Point: overlaps that described for P. australe from C a l i f o r n i a . ]?„ australe i s considered to be a growth form of P_. i r r e g u l a r e , and i s therefore a taxonomic synonym of P. i r r e g u l a r e . D i s t r i b u t i o n a l e v i -dence also supports t h i s conclusion. The known range of _P. i r r e g u l a r e extends from Point Conception, C a l i f o r n i a to. Khantaak Island, near Yakutat., Alaska. Temperature i s considered to be the primary fac-tor c o n t r o l l i n g i t s gross d i s t r i b u t i o n . N i t r a t e and phos-phate deficiency may p a r t i a l l y r e s t r i c t , the d i s t r i b u t i o n of P. i r r e g u l a r e south of Point Conception, C a l i f o r n i a . The sporadic, d i s t r i b u t i o n of P. i r r e g u l a r e on the P a c i f i c Coast i s correlated with the presence of sand, and l o c a l conditions are roost important i.n determining i t s regional d i s t r i b u t i o n . Experimental studies show that _P, i r r e g u l a r e i s well adapted to a sandy habitat, and several features are discussed to explain t h i s adaptation. The laminate plants and germlings of :P:. i r r e g u l a r e t o l e r a t e a wider range i.n temperature and s a l i n i t y i n c u l -ture than that to which they are subjected i n nature. However, the laminate plants and germlings of P, i r r e g u l a r e are very s e n s i t i v e to dessication; under experimental con-d i t i o n s both t o l e r a t e less desiccation than that to which they are subjected under natural conditions. GRADUATE STUDIES F i e l d of Study: Marine Phycology Marine Phytoplankton Chemical Oceanography Physical Oceanography Synoptic Oceanography Phylogenetics and Palaeobotany Protozoology Biochemical Genetics Plant Geography Cytogenetics & Cytology R. F. Scagel R„ F. Scagel P. M. Williams R. W. Burling G„ L. Pickard G. E. Rouse R. B a l l W. Ebersold J„ Gaines H„ L. Lewis Scholarships 1962-65 - National Research Council Studentship Scholarship CONTRIBUTIONS TO THE LIFE HISTORY AND ECOLOGY OF THE MARINE BROWN ALGA PHAEOSTROPHION IRREGULARE S, et G. ON THE PACIFIC COAST OF NORTH AMERICA fey ARTHUR MATHIESON B.A.S University of C a l i f o r n i a , Los Angeles, I960 M.A., University of C a l i f o r n i a , Los Angeles, 1961 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY In the Department of BIOLOGY AND BOTANY We accept t h i s thesis as conforming to, the required standard THE UNIVERSITY OF BRITISH A p r i l , 1965 COLUMBIA In p r e s e n t i n g ' t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia,, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study, I f u r t h e r agree that per-m i s s i o n f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i -c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission* Department of The U n i v e r s i t y of B r i t i s h Columbia, Vancouver 8 ? Canada Date 3 ?—6 % i i ABSTRACT U n t i l recently, few c o l l e c t i o n s of the marine brown alga Phaeostrophion irregulare S. ert G. had been made, l i t t l e was known of i t s ecology, and v i r t u a l l y nothing of i t s l i f e history,, The main objectives of t h i s i n v e s t i g a t i o n were to study the l i f e h i s t o r y and major factors influencing growth and d i s t r i b u t i o n of this species. Laboratory and f i e l d investigations were conducted during 196l-196ii. L i f e h i s t o r y studies were performed i n the labora-tory by culturing zoospores under constant environmental con-d i t i o n s . The growth of cultured germlings and the photosynthetic response of the laminate plants from the f i e l d were recorded under d i f f e r e n t temperatures, s a l i n i t i e s , nutrients, and l i g h t conditions. The tolerance of laminate plants and germlings to extremes of temperature, s a l i n i t y , and desiccation was also determined i n the laboratory. The growth and reproduction of in s i t u plants at Glacier Point, B r i t i s h Columbia were corre-lated with temperature, s a l i n i t y nutrients, t i d e s , sand and various meteorological conditions at that locality.. L i f e h i s t o r y studies were conducted at Glacier Point by observing the succession of germlings on denuded transects and by transplanting laboratory cultured germlings into the f i e l d . The laminate thallus of P. irregulare sometimes bears both u n i l o c u l a r and p l u r i l o c u l a r sporangia at the same time. Pr e v i -ously, only u n i l o c u l a r sporangia were reported i n t h i s plant. i i i Z o o s p o r e s f r o m t h e u n i l o c u l a r s p o r a n g i a ( u n i s p o r e s ) a n d p l u r i ~ l o c u l a r s p o r a n g i a ( p l u r i s p o r e s ) d e v e l o p i d e n t i c a l l y s a n d e a c h i s c a p a b l e o f p r o d u c i n g a l a m i n a t e t h a l l u s d i r e c t l y o r a f t e r a s u c c e s s i o n o f f i l a m e n t o u s a n d d i s c o i d p l e t h y s m o t h a l l i 0 T h e " d i r e c t - t y p e " o f d e v e l o p m e n t o f t h e z o o s p o r e s ( u n i s p o r e s ) f r o m t h e u n i l o c u l a r s p o r a n g i u m i s p r o b a b l y d u e t o a s u p p r e s s i o n o f m e i o s i s i n t h e u n i l o c u l a r s p o r a n g i u m , , M o r p h o l o g i c a l a n d c u l t u -r a l e v i d e n c e i s p r e s e n t e d t o s u p p o r t t h i s h y p o t h e s i s , a l t h o u g h n o c y t o l o g i c a l e v i d e n c e w a s o b t a i n e d , . A t G l a c i e r P o i n t , P . i r r e g u l a r e i s r e s t r i c t e d t o s a n d y a r e a s , , a n d t h e g r e a t e s t n u m b e r o f p l a n t s o c c u r w h e r e l a r g e f l u c t u a t i o n s o f s a n d o c c u r a n n u a l l y . T h e p l a n t s a r e r e g u l a r l y b u r i e d f o u r t o s i x m o n t h s p e r y e a r , , a n d t h e i r g r o w t h a n d r e p r o d u c t i o n i s l i m i t e d t o t h e p e r i o d w h e n s a n d i s a b s e n t . C o m p e t i t i o n w i t h o t h e r p l a n t s p r o b a b l y a c c o u n t s f o r t h e o c c u r r e n c e o f J?. i r r e g u l a r e i n s a n d y a r e a s , s i n c e i t w i l l g r o w i n r o c k y a r e a s i f o t h e r a l g a e a r e e l i m i -n a t e d . T h e p e r i o d o f m a x i m u m g r o w t h ( F e b r u a r y t o A p r i l ) i s a s -s o c i a t e d w i t h a c o r r e s p o n d i n g i n c r e a s e i n l i g h t i n t e n s i t y a n d w a t e r t e m p e r a t u r e i n t h i s a r e a . A f t e r A p r i l , g r o w t h i n n o n = t i d e p o o l p o p u l a t i o n s d e c r e a s e s m u c h m o r e r a p i d l y t h a n g r o w t h o f t i d e p o o l p o p u l a t i o n s , b e c a u s e o f t h e i n c r e a s e d e x p o s u r e o f p l a n t s t o d e s i c c a t i o n d u r i n g d a y l i g h t . A p e r i o d o f d e c r e a s e d g r o w t h f o r t i d e p o o l p l a n t s o c c u r s i n M a y t o J u n e ; t h i s d e c r e a s e p r o b a b l y r e s u l t s f r o m h i g h s u r f a c e w a t e r t e m p e r a t u r e s , h i g h l i g h t i n t e n s i = t i e s 5 o r a c o m b i n a t i o n o f b o t h . i v The morphology of the laminate plants of P. irregulare i s extremely variable and the range of v a r i a b i l i t y observed at Glacier Point overlaps that described f o r P_. australe from C a l l - v f o r n i a . P. australe i s considered to be a growth form of P. irregulare j and i s therefore a taxonomic synonym of _P„ irregu,-lare«, D i s t r i b u t i o n a l evidence also supports t h i s conclusion. The known range of P_„ irregulare extends from Point Con-ception,, C a l i f o r n i a to Khantaak Island^, near Yakutat g Alaska. Temperature i s considered to be the primary fa c t o r c o n t r o l l i n g i t s gross d i s t r i b u t i o n . Nitrate and phosphate deficiency may p a r t i a l l y r e s t r i c t the d i s t r i b u t i o n of P„ irregulare south of Point Conceptions, C a l i f o r n i a . The sporadic d i s t r i b u t i o n of P. irregulare on the P a c i f i c Coast i s correlated with the pres-ence of sand, and l o c a l conditions are most important i n deter-mining i t s regional d i s t r i b u t i o n . Experimental studies show that P_„ irregulare i s well adapted to a sandy habitat, and several features are discussed to explain t h i s adaptation. The laminate plants and germlings of P„ irregulare tolerate a wider range i n temperature and s a l i n i t y i n culture than that to which they are subjected i n nature. However, the laminate plants and germlings of _P„ irregulare are very sensitive to desic-cation; under experimental conditions both tolerate less desic-cation than that to which they are subjected under natural conditions. V T A B L E OF CONTENTS I . I N T R O D U C T I O N ' 1 I I . T E R M I N O L O G Y . . . ... 1+ I I I . MORPHOLOGY A N D L I F E H I S T O R Y OP P H A E O S T R O P H I O N I R R E G U L A R E . 6 A . M o r p h o l o g y . . 6 B . C u l t u r a l S t u d i e s . . 1 3 1. M e t h o d s . . . . . . . . 13 2. O b s e r v a t i o n s . . . . . . . 13 C . F i e l d S t u d i e s . . . . 22 1. M e t h o d s . . . . . . 22 2. R e s u l t s . . . . . . . . . . . 23 D. D i s c u s s i o n o f M o r p h o l o g y and L i f e H i s t o r y . . 2 6 I V . A U T E C O L O G Y OF P H A E O S T R O P H I O N I R R E G U L A R E A T G L A C I E R PO I N T , . BR I T I S H C O L U M B I A . . . . . 31+ A . M e t h o d s . . 31+ B. E n v i r o n m e n t . . . . . . o . . . . . . . . . . . . 38 1. S a n d F l u c t u a t i o n . . . . . . . . . . . . . . . . . . . . . . 38 2. T i d e s . . . 1+0 3. S e a w a t e r T e m p e r a t u r e . . . . . . . . . . . . . . . . 1+2 i j . . S a l i n i t y 1+2 5 . N u t r i e n t s . 1+3 a . N i t r a t e s . . . . . . . . . . . . . . . . 1+3 b . P h o s p h a t e s . . . 1+1+ 6. M e t e o r o l o g i c a l C o n d i t i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . 1+5 C . O c c u r r e n c e o f P . i r r e g u l a r e and o t h e r a l g a e 1+6 D . G r o w t h a n d V a r i a b i l i t y o f M a t u r e P l a n t s i n t h e F i e l d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 E . S e a s o n a l P e r i o d i c i t y o f R e p r o d u c t i o n . 51+ F . D i s c u s s i o n o f A u t e c o l o g y o f P . i r r e g u l a r e a n d i t s i m p l i c a t i o n u p o n t h e t a x o n o m y of--.JP. a u s t r a l e . . 5 5 V . EXPERIMENTAL E C O L O G Y . . . . . . . . . . . . . . . . . . . . . . . . 6 l A . G r o w t h o f G e r m l i n g s . . . . . 6 1 1. M e t h o d s . . . . . . . . . . . . . . . . . . . . . 6 1 2. R e s u l t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 a . S a l i n i t y . . . . . . . . . . . . . 63 b . T e m p e r a t u r e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61+ c . T e m p e r a t u r e a n d S a l i n i t y . . . . . . . . . . . . 65 d . N i t r a t e . . . . . . . . . . . . . . . . . . . . . . . . . . 66 e . P h o s p h a t e . . . . . . . . . . . . 66 f . L i g h t I n t e n s i t y . . 67 g . L i g h t Q u a l i t y . . . . . . . 68 3. D i s c u s s i o n o f G r o w t h o f G e r m l i n g s . . . 68 v i Table of Contents (Cont'd) B. Photosynthesis and Respiration of Macroscopic. Plants ........................... Ik 1. Methods........ lk 2 . ReSU.ltS. 0 . . . . O . . . O O . O . . . O . . O 0 O . . . . . O 0 . 9 0 . 0 . . . - 0 7^ a. Light I n t e n s i t y . . . . . . . . . . . . . . . . o . . . o . . . . . 76 b. Temperature.............................. 77 C * S0.1imty #« o « » « • so* o « oo o o o o e eo •« o a o © o o oo T T d. Nutrients...... 78 3. Discussion of Photosynthesis and Respiration i n Macroscopic Plants... 79 C. Tolerance Experiments oh Germlings and Macroscopic Plants 85 1. Methods. 85 a. Temperature Tolerance., 85 b. S a l i n i t y Tolerance 86 c. Desiccation Tolerance 87 2. Results 88 a. Temperature Tolerance..................... 88 b. S a l i n i t y Tolerance 89 c. Rate of Water Loss 89 d. Resistance to Desiccation..... 90 e. Lethal Desiccation Time of Germlings..... 91 f. Survival i n the Dark 91 3. Discussion of Tolerance Experiments.......... 91 VI. GENERAL DISCUSSION AND CONCLUSIONS. .. 96 VII. SUMMARY „ •. ... 102 APPENDIX I. Tables I-XV APPENDIX II. Figures 1=92 v i i LIST OP TABLES Table I. Summary of Culture Media. I I . Denuded Transect #1. III. Denuded Transect #2. IV. Denuded Transect #3. V. Sand Analysis. VI. T i d a l Factors at Glacier Point, 196ii ( f t ) . VII. Maximum and Minimum Daily Exposure Periods (min). f o r Various T i d a l Levels (0.5 to 5.0 f t ) at Glacier Point. VIII. L i s t of Plants Present i n Areas 6a, 6b, and 7. IX. Transect of Areas 6a and 6b (1 to 5 f t ) , May 23, 1963. X. Survival of Unispores at Various S a l i n i t i e s and Temper-atures, A f t e r 50 Days. XI. Growth of Germlings Under Different Light Q u a l i t i e s . XII. A r t i f i c i a l Seawater. XIII. Diethanolamine Solution for G0^ Atmosphere. XIV. P/R Ratios at Different Temperatures. XV. Voucher Specimens of P. irre g u l a r e . v i i i LIST OF FIGURES Figures 1 . D i s t r i b u t i o n of Phaeostrophion irregulare S. ejt G. on the P a c i f i c Coast of North America. 2. Developmental'Morphology of Macroscopic Stages of P. irr e g u l a r e , i n s i t u . 3. Holdfast Morphology and Blade Development of P. irregulare . Reproductive Morphology of P. irregulare . 5". Reproductive Morphology of P. i r r e g u l a r e . 6 . Development of Unispores and Plurispores. 7. Filamentous and Discoid Plethysmothalli. 8 . Discoid Plethysmothalli. 9 . F i r s t and Second Generations of Discoid Plethysmothalli, Intermediate Germlings, and i r r e g u l a r d i s c s . 10. Irregular Discs. 1 1 . Young Holdfasts of P. irregulare from Culture and i n s i t u . 1 2 . Blade I n i t i a l s of P. irregulare and Petalonia d e b i l i s . 1 3 . Reproductive Organs on Cultured Germlings. l i | . Reproductive Organs on Cultured Germlings. 15. A. Comparison of Surface C e l l Dimensions of Mature Blades from Base to Apex. 1 6 . Generalized L i f e History of Phaeostrophion irregulare S. et G. 1 7 . D i s t r i b u t i o n of P. irregulare i n the V i c i n i t y of Glacier Point. 1 8 . V a r i a t i o n of Sand Levels i n Areas 6 a and 6b During I96J4.. 1 9 . V a r i a t i o n of Sand Levels i n Area 6 a , 1 9 6 I i , 2 0 . Variation of Sand Levels i n Area 6 b , I963-6I4 . . 2 1 . Various Habitats on East Side of Glacier Point. 2 2 . V a r i a t i o n of Sand Level on Area 6 a , June 23-December 1 , 1 9 6 3 . 2 3 . V a r i a t i o n of Sand Level on Area 6 b , June 23-November 1 7 , 1 9 6 3 . 2I4.. V e r t i c a l D i s t r i b u t i o n of the Conspicuous Plants at Glacier Point (Areas 6 a , 6 b , 7)j> Expressed as Feet Above T i d a l Datum Level. 25. V a r i a t i o n of Sand Levels i n Several Habitats of P_. irregu-lare , 1963-6)4.. 2 6 . Total Number of Exposures per Month of Various Levels (1-5 f t ) i n the I n t e r t i d a l Zone at Glacier Point, 1963-61].. 2 7 . T i d a l Features of Greatest Exposure Periods During the Night (Winter) at G l a c i e r Point, I96I4.0 2 8 . T i d a l Features of Greatest Exposure Periods During the Day (Spring and Summer) at Glacier Point, I96J4.. 2 9 . Exposure of Different Levels to A i r Throughout the Year at Glacier Point, 1958-59. Expressed as the Mean Number of Minutes per Each Day of Exposure During the Month. 3 0 . Values of Surface Water Temperatures at Glacier Point, June 1 9 6 3 to August I96I4.. 31. Values of Surface Water Temperatures at Neah Bay, Washing-ton, U.S.A., 1931).-1-960. 3 2 . Values of Surface Water S a l i n i t y at Glacier Point, June 1 9 6 3 to July 1 9 6 i i . i x Figure 33. Values of Surface Water S a l i n i t y at Neah Bay, Washington, U.S.A., 193M-960. 3i+. Seasonal Values of Soluble Nitrate i n Surface Waters at Glacier Point, 1963-1961+. 35. Seasonal Values of Reactive Phosphorus i n Surface Waters at Glacier Point, 1963-1961+,' 36. Monthly P r e c i p i t a t i o n at Jordan River, B.C. 37. Monthly A i r Temperatures at Jordan River, B.C. 38. V e r t i c a l D i s t r i b u t i o n of Dominant Plants on Three Adjoin-ing Areas, 6a, 6b and 7, Expressed as Feet Above T i d a l Datum Level. 39. A l g a l Associations i n Area 6a. 1+0, Appearance of JP. irregulare i n Areas 6a, 6b. 1+1'. Plants i n Area 6a. 1+2, A l g a l Associations i n Sandy Areas at Glacier Point. 1+3» Sand Fluctuation i n a Location t o the North of Area 6a and Associated Vegetation. 1+1+. Habitat of Area 7 and Associated Plants. 1+5. Growth of Plants of P. irregulare at Glacier Point, Expressed as Grams Fresh Weight of Blades/ra . 1+6. Growth of Plants of P.. irregulare at Glacier Point, Expressed as Grams Fresh Weight of Blades/ra . 1+7. Growth of Plants of P. irregulare at Glacier Point, Expressed as Grams Fresh Weight of Blades/m . 1+8i Growth of Tide Pool Plants of JP. irregulare i n Area 6a, Expressed as Percent Occurrence of Different Size Classes, 1963-61+. 1+9. Growth of Tide Pool Plants of P. irregulare i n Area 5, Expressed as Percent Occurrence of Different Size Classes, 1962-63.-50. Growth of Non-Tide Pool Plants of P. irregulare i n Area 6a, Expressed as the Percent Occurrence of Different Size Classes, 1963-6I+. 51. Growth of Non-Tide Pool Plants of P. irregulare on a Sloping Surface i n Area 6a, Expressed as the Percent Occurrence of Different Size Classes, 1963. 52. Growth of JP. irregulare at Glacier Point, Expressed as the Mean Blade Length, .1963-61+. 53. Growth of_P. irregulare at Glacier Point, Expressed as the Mean Blade Length, 1963-61+. 51+. V a r i a t i o n of Blade Length of P. irregulare at Different V e r t i c a l Heights. 55. V a r i a t i o n of Blade Length at Different V e r t i c a l Heights on a Sloping Substratum. 56. Blade Morphology of Mature Plants of P. i r r e g u l a r e . 57. Reproductive Cycle of P. irregulare During 1963, and Percent of Various Reproductive Organs. 58. V a r i a t i o n of Monthly Hours of Bright Sun at Jordan River. 59. Absorption Spectra of Cellophane F i l t e r s . 60. Spectral Energy D i s t r i b u t i o n Curve of Cool-White Lamps. 61. Response Curve of Phototube c of Photovolt E l e c t r o n i c Photometer. X Figure 62. Growth of Germlings from Unispores i n Different S a l i n i t i e s A f t e r , 25 Days, 63. Growth of Germlings from Plurispores i n Different S a l i n i -t i e s , A f t e r 10 and 35 Days. 6I4.. Growth of Germlings from Plurispores i n Different S a l i n i -t i e s , After 10 and 35 Days. 6 5 . Growth of Germlings from Unispores i n Different S a l i n i t i e s , A f t e r 20 Days. 66. Growth of Germlings from Plurispores at Different Temper-atures ( S a l i n i t y 31»4- °/oo). 67. Growth of Germlings from Unispores at Different.Temper-atures (iSalinity 31.4- °/oo). 68. Growth of Germlings from Unispores i n Various S a l i n i t i e s and Temperatures, After 30 Days. 69. Growth of Germlings from Plurispores i n Various S a l i n i t i e s and Temperatures, After 30 Days. 70. Germination of Unispores i n Different S a l i n i t i e s (10°C). 71. Germination and Survival of Germlings i n Different S a l i n i -t i e s ( 2 0°C) o 72. Growth of Unispores i n Natural Seawater with Additions of N i t r a t e , After 20 Days. 73. Growth of Unispores i n Natural Seawater with Additions of Phosphate, After 20 Days. 7J4.. Growth of Germlings from Unispores and Plurispores Under Different Light I n t e n s i t i e s , A f t e r 25 Days. 75. Apparent Photosynthesis of the Blades and Holdfasts of P. irregulare at Different Light I n t e n s i t i e s and 11.5°G. 76. Rate of Apparent Photosynthesis of the Blades and Hold-fasts of P. irregulare at Different Temperatures.' 77. Rate of Respiration of the Blades and Holdfasts of P. irregulare at Different Temperatures. 78. Rate of Apparent Photosynthesis of Blades of P. irregulare at Different S a l i n i t i e s and 11.5°C. 79. Rate of Respiration of Blades of P. irregulare at D i f f e r -ent S a l i n i t i e s and 1 1 .5°C 8 0 . Rate of Apparent Photosynthesis of Blades of P. irregulare i n Different Supplements of Phosphate. 81. Rate of Apparent Photosynthesis of Blades of P. irregulare in Different Supplements of N i t r a t e . 82. Temperature Tolerance of Common Plants at Glacier Point. 8 3 . Germination of Plurispores A f t e r Exposure to Various Temperatures. 8 i i . Temperature Tolerance of Blades of P_, irregulare at v a r i -ous S a l i n i t i e s . 85. Temperature Tolerance of the Macroscopic Plants of P_. irregulare to a Sudden Immersion i n a High Temperature. 86. S a l i n i t y Tolerance of the Macroscopic Plants of P. irregu -lare After Different Periods of Time. Length of Bar Indicates L i v i n g Plants. 8 7 . S a l i n i t y Tolerance of Several of the Conspicuous Plants at Glacier Point, After 2ii Hours. 88. Average Water Loss of Complete Macroscopic Plants of JP. irregulare at Different Temperatures i n the Laboratory. x i Figure 89. Average Water Loss of Blades and Holdfasts of P. irregulare at 20°C i n the Laboratory. 90. Average Water Loss of Complete Macroscopic Plants of P. irregulare i n Nature. 91. L e t h a l i t y of the Blades of P. irregulare versus Water Loss. 92. Temperature and S a l i n i t y Near Populations of P. irregulare on the P a c i f i c Coast of North America. x i i A C K N O W L E D G E M E N T S • I w i s h t o e x p r e s s my g r a t i t u d e t o a n u m b e r o f p e o p l e a t 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 w h o h a v e made t h i s s t i i d y p o s s i b l e s t o D r . R . F . S c a g e l f o r h i s d i r e c t i o n , a d v i c e a n d f i n a n c i a l s u p p o r t , p r o v i d e d b y a r e s e a r c h g r a n t f r o m t h e D e f e n c e R e s e a r c h B o a r d o f C a n a d a , ( D R B 9 5 2 0 ~ l l i ) j t o D r . G 0 R o u s e f o r h i s h e l p f u l s u g g e s t i o n s a n d d i s c u s s i o n s ; t o D r . G . L . P i c k a r d a n d D r . J . S t e i n f o r t h e i r h e l p a t v a r i o u s s t a g e s o f t h i s s t u d y ! t o M r . L . D r u e h l a n d M r . L . H a n i c f o r t h e i r i n v a l u a b l e c r i t i * * . c i s m s a n d h e l p f u l s u g g e s t i o n s ; t o M r . J , T h o r p e f o r h i s m e c h a n i -c a l a n d t e c h n i c a l a s s i s t a n c e . I w o u l d a l s o l i k e t o a c k n o w l e d g e t h e a s s i s t a n c e o f M r . K . S t e v e n s o f t h e M a r i n e B i o l o g i c a l S t a t i o n a t N a n a i m o , B r i t i s h C o l u m b i a , w h o p r o v i d e d some o f t h e c h e m i c a l a n a l y s e s ; t h e h o s p i t a l i t y o f M r . A . P a c k h a m a n d M i s s P a c k h a m , a t • P o i n t - N o - P o i n t R e s o r t ( G l a c i e r P o i n t ) , B r i t i s h C o l u m b i a , d u r i n g t h e c o u r s e o f t h e f i e l d i n v e s t i -g a t i o n s ; t h e l o a n o f s p e c i m e n s f r o m D r . P . O . S i l v a o f t h e U n i v e r s i t y o f C a l i f o r n i a , B e r k e l e y , D r . M . S . D o t y , U n i v e r s i t y o f H a w a i i , a n d D r . E..Y. D a w s o n , S a n D i e g o M u s e u m o f N a t u r a l H i s t o r y ; t h e c o u r t e s y o f t h e C a n a d i a n H y d r o g r a p h i c S e r v i c e f o r s u p p l y i n g t i d a l r e c o r d s f o r V a n c o u v e r I s l a n d , a n d f o r t h e i r p a t i e n c e i n a t t e m p t i n g t o e s t a b l i s h a t i d a l r e c o r d i n g m a c h i n e a t G l a c i e r P o i n t . I am e s p e c i a l l y g r a t e f u l t o t h e D e p a r t m e n t o f B i o l o g y a n d B o t a n y a n d t h e I n s t i t u t e o f O c e a n -o g r a p h y o f 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 , f o r t h e u s e o f f a c i l i t i e s a n d e q u i p m e n t ; a n d t o t h e N a t i o n a l R e s e a r c h C o u n c i l o f C a n a d a f o r a w a r d i n g a s t u d e n t s h i p d u r i n g t h e y e a r s 1 9 6 2 t h r o u g h I96I4.. -1= I. INTRODUCTION The marine brown alga Phaeostrophion irregulare S„ _et G. is a member of the order Dlctyosiphonales and family Punctari-aceae. It i s r e s t r i c t e d to the P a c i f i c Coast of North America. Setchell and Gardner (192k) f i r s t described the monotypic genus Phaeostrophion with i t s single species (JP. irregulare ) from material c o l l e c t e d at Bolinas, C a l i f o r n i a (N.L. Gardner #k582) 0 One other c o l l e c t i o n of P. irregulare was recorded by Setchell and Gardner (192k, 1925) from Cape Arago, Oregon (N.L. Gardner #2673). They give (192k, 1925) a detailed description of the plant, but unfortunately a l l of t h e i r specimens possessed old,, battered blades, and they did not observe any zoospores. U n t i l recently, very few other c o l l e c t i o n s of P_. irregulare had been made, l i t t l e had been known of i t s ecology, and v i r t u a l l y noth-ing of i t s l i f e h i s t o r y . Sanborn and Doty (19kk) recorded P. irregulare at Lighthouse Reef near Cape Arago, Oregon. Doty (19h7) recorded P. irregulare as l o c a l l y abundant around the margins of sandy tide pools at mean lower low water, southwards of Seal Rock, Oregon, and described the development of the blades. Dawson (1958) described a second species of Phaeostrophion (Z," australe) from Point Conception (Government Point), C a l i f o r -n i a . He states that s t r u c t u r a l l y and reproductively the two species are much a l i k e , but that P. australe i s much smaller than P. ir r e g u l a r e . He also suggests that there i s a marked geographic d i s c o n t i n u i t y between the two species, f o r P. i r r e g u -lare i s not known south of Bolinas, C a l i f o r n i a . -2-The sporadic d i s t r i b u t i o n of P. irregulare on the P a c i f i c Coast and i n B r i t i s h Columbia, and the occurrence of several populations l o c a l l y at Glacier Point, B r i t i s h Columbia, stimu-lated the writer to make a more detailed study of P. irregulare and the factors responsible f o r i t s d i s t r i b u t i o n . The primary objectives of the investigation were two-fold: (1) to study the l i f e h i s t o r y i n nature and in the laboratory, and (2) to study the major factors influencing i t s growth and reproduction. In order to achieve these objectives, laboratory and f i e l d i n v e s t i -gations were conducted. A l l of the laboratory experiments were performed at the University of B r i t i s h Columbia during 1961 to 1961+, and most of the f i e l d work was c a r r i e d out at G l a c i e r Point, B r i t i s h Columbia during the same period. Laboratory cultures were i n i t i a t e d under controlled environ-mental conditions i n order to study the development and response of the germlings. Cultures were subjected to various environ-mental conditions, including temperature, s a l i n i t y , nutrients and l i g h t . The photosynthetic response of macroscopic plants to s i m i l a r conditions of temperature, s a l i n i t y , nutrients and l i g h t i n t e n s i t y was determined by use of the Warburg apparatus. Experiments were conducted to test the tolerance of mature plants and germlings to extremes of temperature, s a l i n i t y and desiccation. L i f e h i s t o r y studies were conducted i n the f i e l d by observing the succession of germlings on denuded transects, and by trans-planting laboratory cultured germlings into the f i e l d . The growth and reproduction of in s i t u plants at Glacier Point were compared with the v a r i a t i o n of environmental factors, such as temperature, s a l i n i t y , nutrients, t i d e s , sand and various meteorological con-d i t i o n s . Glacier Point ( l a t . 1+8° 23' N, long. 123° 59' W) i s a semi-exposed beach on the southwest coast of Vancouver Island, B r i t i s h Columbia. It i s located on Juan de Fuca S t r a i t , approximately 1+0 miles west of V i c t o r i a and four miles east of Jordan River (Fig. 1). Although most of the field.work was conducted at Glacier Point, general observations of P. irregulare were made elsewhere on Vancouver Island at Box Island near Long Beach ( l a t . [+9° 0l+! N, long. 125° 1+7! W), Brooks peninsula ( l a t . 50° 07' N, long. 127° 1+2' W); and i n the state of Washington, U.S.A. at Ruby Beach ( l a t . 1+7° 1+3' N, long. 121+° 25' W), and Cattle Point, San Juan Island ( l a t . 1+8° 27« N, long. 122° 57'W) (Fig. 1 ) . II. TERMINOLOGY To d i s t i n g u i s h c l e a r l y between the various stages and structures i n the l i f e h i s t o r y of P. irreg u l a r e, the following terminology i s employed. (1) Mature t h a l l u s . The broad, flattened, erect macro-scopic stage occurring i n nature. It consists of at least one laminate thallus (blade) and the holdfast (usually several erect laminae arise from the same h o l d f a s t ) o (2) P l u r i l o c u l a r sporangium. The m u l t i c e l l u l a r sporangium produced on the mature thallus when i t becomes f e r t i l e . Its spores are designated as plurispores to indicate t h e i r o r i g i n . (3) Unilocular sporangium. The one-celled sporangium pro-duced on the mature thallus when i t becomes f e r t i l e . Its spores are designated as unispores to indicate t h e i r o r i g i n . (k) Plethysmothallus. The microscopic germling stage which i s capable of reproducing i t s e l f and i n i t i a t i n g the macroscopic stage (mature t h a l l u s ) . (5) Piethysmoplurisporangium. The m u l t i c e l l u l a r sporangium produced on the plethysmothallus. Its spores are desig-nated as plethysmoplurispores to indicate t h e i r o r i g i n and type of sporangium from which they a r i s e . (6) Plethysmounisporangium. The one-celled sporangium pro-duced on the plethysmothallus. Its.spores are -5-designated as plethysmounispores to indicate t h e i r o r i g i n and type of sporangium from which they a r i s e . (7) Heteroblasty. The production of two types of germ-li n g s from zoospores of the same sporangium (Sauvageau 192ka). -6-I I I . MORPHOLOGY AND LIFE HISTORY OF PHAEOSTROPHION IRREGULARE A. Morphology The mature thallus of P. irregulare consists of several l i g u l a t e blades attached to a basal holdfast (Fig. 2e,g). The blades are often i r r e g u l a r l y torn, and they vary i n size from 1.0 to 25 .0 cm long and 0 .5 to Ij..5 cm wide. I n i t i a l l y , the holdfast i s a small, crustose disc (Fig. l l e , f ) resembling a species of R a l f s i a , but eventually i t may reach a diameter of 20 cm. The holdfast of P. irregulare i s a perennial structure, but except f o r t h e i r basal remnants, the blades die soon a f t e r they become f e r t i l e . As described by Doty (19l|7)> the blades originate as knobs on the holdfast (Fig. 2 i and 3 a ) . These knobs or i n i t i a l s l a t e r become elongated into f i n g e r - l i k e extensions that i n turn become expanded d i s t a l l y into flattened blades (Fig. 3b). The blade i n i t i a l s are m u l t i c e l l u l a r when they are f i r s t detectable on the holdfast. Figures 3c and 2a show that the tissues of the hold-fa s t are continuous with those of the young blades, and c e l l d i f f e r e n t i a t i o n i s s i m i l a r to that described by S e t c h e l l and Gardner (19214., 192$) f o r the mature blades: larger c e l l s occur i n t e r n a l l y , and smaller c e l l s externally. Each surface c e l l contains a single nucleus and several flattened chloroplasts, whereas few chloroplasts are present i n the internal c e l l s . A l -though most of the c e l l s are thin-walled, the elongated central c e l l s often become thick-walled and filamentous (Fig. $e). F i g -ure 5d,e shows respectively cross-sectional views of young and mature blades of JP. i r r e g u l a r e . -7-Since the holdfast i n i t i a t e s new blades each year, i t becomes very complex. A cross section of an old holdfast shows several layers of overlapping discs and remnants of blades which have been buried during the process of blade i n i t i a t i o n (Pig. 3 c ) . In many specimens the o r i g i n of several overlapping layers can be traced back to a single locus i n the holdfast, because of the continuity of the c e l l s from one layer to another. New blades sometimes originate from tissue regions of the holdfast that actually represent the remnants of ei t h e r old discs or old, eroded blades. The growth of the blades occurs c h i e f l y from a l o c a l i z e d basal raeristem. Doty (19h7) assumed that this was the case, since he observed that the stipe did not elongate as the plant became older, and that loss of the terminal part of the blade f a i l e d to i n h i b i t growth of the blade. Pigure 2h shows the region of the meristem on an old blade. A comparison of the surface c e l l dimensions of the blade from base to- apex shows that the smallest c e l l s are located below the point of t r a n s i -tion of the stipe to blade, i n d i c a t i n g the meristem is r e s t r i c -ted to this general region (Pig. 15)» In young blades there is no conspicuous gradient i n c e l l s i z e , whereas i n mature blades there i s a pronounced gradient. A microscopic exami-nation of the surface c e l l s of a mature blade shows that the oldest c e l l s at the top of the blade are more spherical and more highly vacuolated than the basal c e l l s . Also, the chloro-plasts i n the older c e l l s are more cl o s e l y r e s t r i c t e d to the l a t e r a l walls. -8-The sporangia are formed by the metamorphosis of the surr face c e l l s of the blade, and these f e r t i l e structures can f i r s t be distinguished microscopically as d i s t i n c t l i n e s of l i g h t e r c e l l s above the stipe (Fig. l+c). On mature plants the sporangia occur i n a broad layer over almost the entire surface of the blade. Various developmental stages of the sporangia can be observed when the surface c e l l s are mi c r o s c o p i c a l l y examined from base to apex of the blade. Both uni l o c u l a r and p l u r i l o c u -l a r sporangia may occur together on the same blade (Fig. i+j), but most plants bear only un i l o c u l a r .sporangia (Fig. l+d). Setchell and Gardner (192lj., 1925) report only unilocular sporangia, but during A p r i l to May, p l u r i l o c u l a r sporangia are very abundant. The two types of sporangia are distinguishable at an early stage, because the un i l o c u l a r i n i t i a l s are much l i g h t e r i n color than the p l u r i l o c u l a r . Figure lie shows a surface view of the unilocu-l a r i n i t i a l s . As the unil o c u l a r sporangia mature (Fig. 5a), they enlarge very r a p i d l y to a diameter of 20 to 35 u at maturity (Fig. l+.d)0 At this stage, the sporangia are more or less spherical i n surface view, and do not project above the blade surface. In cross section the mature sporangia are 30' to 60 u high and 20 to 35 P wide (Fig. 5d,e,f)„ The mature unispores (Fig. lie,f) are libe r a t e d through a pore formed at the apex of the sporangium. In rare instances they were ejected from the sporangium while s t i l l enclosed i n a transparent membrane. The unispores are of the t y p i c a l form f o r the Phaeophyceae, with one to two disco i d chloroplasts, a red eyespot and two l a t e r a l l y inserted f l a g e l l a of _ 9 ~ unequal length. The longer flagellum i s directed forward, and the shorter one backward. The eyespot i s crescent-shaped and i s embedded i n the chloroplast close to the in s e r t i o n of the f l a g e l l a . The chloroplast(s) occupies the posterior portion of the zoospore, while several fucosan v e s i c l e s are present i n the anterior part. The zoospores are approximately k.k to 7.0 u long (exclusive of the f l a g e l l a ) , and 2.3 to 3.1 P- i n diameter. The shorter f l a g e l l a i s about 6.0 to 8.6 u long, and the longer f l a g e l l a i s about 10 to 13 p long. The uni-spores were never observed to be p o s i t i v e l y phototactic. Although the s o r i with u n i l o c u l a r sporangia are d i s t r i -buted over the entire surface of the blades, not a l l of the surface c e l l s develop into sporangia. Many s t e r i l e c e l l s are scattered among the unil o c u l a r sporangia, but the vegetative c e l l s never a t t a i n the same size as the sporangia (Pig. hd,j and 15). This i s i n marked contrast to the condition in the s o r i with p l u r i l o c u l a r sporangia, where almost a l l c e l l s develop into sporangia (Pig, kb). When f i r s t d i f f e r e n t i a t e d , the p l u r i l o c u l a r i n i t i a l s are darker than the u n i l o c u l a r . This i s because each p l u r i l o c u l a r sporangium i s produced from the d i v i s i o n of one c e l l into several locules, and each locule has one to two chloroplasts. Thus, there i s a greater concentration of chloroplasts i n a sorus of p l u r i l o c u l a r than i n a sorus with un i l o c u l a r sporangia. Each p l u r i l o c u l a r sporangium i s produced by numerous p e r i c l i n a l and a n t i c l i n a l d i v i s i o n s of a single surface c e l l . -10-Most commonly, the a n t i c l i n a l d i v i s i o n s are i n i t i a t e d p r i o r to the p e r i c l i n a l d i v i s i o n s (Pig. lib, 5b). A surface view shows that the i n i t i a l of a p l u r i l o c u l a r sporangium divides a n t i -c l i n a l l y into approximately l\. to 16 locules (Pig. ij.b,j). P e r i -c l i n a l d i v i s i o n s then occur and each longitudinal locule divides into approximately 8 to 12 locules (Pig. 5b,c). Thus, at maturity a single p l u r i l o c u l a r sporangium w i l l contain between 32 to 192 lo c u l e s , and measures 35 to 75 u long and 10 to 25 u wide. In surface view, each locule contains a single nucleus and one or two chloroplasts. Eventually, the contents of each locule become rounded and transformed into a single plurispore, which i s l i b e r -ated a f t e r the p a r t i t i o n i n g walls of the sporangium break down (Pig. iia). Figure lig,h,i shows several plurispores, while Figure 5c shows mature p l u r i l o c u l a r sporangia p r i o r to zoospore l i b e r -ation. The plurispores are morphologically i d e n t i c a l to the unispores. Two-celled paraphyses are usually associated with p l u r i -l o c u l a r sporangia (Fig. l+a), but they have never been found among the un i l o c u l a r sporangia. When uni l o c u l a r and p l u r i l o c u -l a r sporangia occur together i n the same sorus, very few para-physes are found, and they are r e s t r i c t e d to the p l u r i l o c u l a r portion of the t h a l l u s . The paraphysis represents a d i f f e r -entiated surface c e l l , which divides p e r i c l i n a l l y into two c e l l s , the outermost of which becomes s l i g h t l y expanded at the t i p . In cross section, the outer walls of the paraphyses appear very thick and somewhat laminated. In cross section, the paraphyses measure 35 to 75 u high and 12 to 18 u wide, and i n surface -11-view, 12 to 18 u i n diameter (Pig. kb). Large areas of surface tissues are sloughed off the laminate thallus when the plurispores are l i b e r a t e d , and the f e r t i l i t y of such a plant i s e a s i l y detected macroscopically at that time. In contrast, a f e r t i l e plant that has li b e r a t e d unispores does not show extensive shedding. The difference between the two i s related to the method of zoospore l i b e r a t i o n and s t r u c t u r a l features of t h e i r s o r i . The former feature i s probably the most important difference between the two s o r i , f o r a greater part of the p l u r i l o c u l a r sporangial wall i s broken down during the l i b e r -ation of plurispores than i n the unil o c u l a r sporangial wall. Although sporangia are usually r e s t r i c t e d to the blades of ?. i r r e g u l a r e , i n a few instances u n i l o c u l a r sporangia are found on the holdfast. These sporangia appear i d e n t i c a l to those found on the laminate thallus and are produced d i r e c t l y from surface c e l l s of the holdfast. No p l u r i l o c u l a r sporangia were found on any holdfast. The mature plants of JP. irregulare can be e a s i l y mistaken fo r those of Petalonia d e b i l i s (C. Agardh) Derbes e_t S o l i e r f. d e b i l i s , and the s i m i l a r i t y of p l u r i l o c u l a r - b e a r i n g t h a l l i of the two plants may have caused m i s i d e n t i f i c a t i o n i n the past. Several features d i s t i n g u i s h the two plants: (1) no thi c k -walled medullary filaments are present in the blades of P. de-b i l i s ; (2) the surface c e l l s of P. d e b i l i s have one p a r i e t a l chloroplast i n each c e l l , whereas i n JP. irregulare there are several flattened chloroplasts i n each c e l l ; (3) the blade of P. d e b i l i s i s i n i t i a t e d by numerous transverse and lo n g i t u d i n a l -12-d i v i s i o n s of uniseriate filaments (Pig. 12d-f), whereas the blade of P. irregulare i s i n i t i a t e d as a m u l t i c e l l u l a r outgrowth (knob) from the holdfast (Pig. 12a-c); Ck) c o l o r l e s s hairs are commonly produced from the blades of P. d e b i l i s , but are appar-ently absent i n P. irregulare; (5) the holdfast of P. irregulare i s perennial, but that of P. d e b i l i s i s annual; (6) the hold-fas t of P. d e b i l i s i s less extensive than that of P. i r r e g u l a r e . -13-B. Cu l t u r a l Studies 1. Methods F e r t i l e plants of P. irregulare collected during the spring and early summer of 1962, 1963 and 196b, at Glacier Point were used to i n i t i a t e culture studies. A dense inoculum of zoospores (15 to 25 cc)jobtained from a clean soral section, was pipetted into a p e t r i dish with 150 cc of culture solution (Table I ) . The germling development was studied a f t e r attachment of the zoospores to slides or cover s l i p s , which were placed i n the culture dishes. Clonal cultures were i n i t i a t e d by picking up clean, f r e e - f l o a t i n g germlings with,a hooked c a p i l l a r y pipette and by depositing them i n test tubes f i l l e d with 20 cc of culture solution (Table I ) . The growth and development Of single germ-lin g s were then followed. The germlings were grown at 10°C under a l i g h t i n t e n s i t y of 100 foot-candles provided by cool-white fluorescent tubes. A photoperiod schedule of lq. hours of l i g h t and 10 hours of darkness was used. The culture solutions were changed every 10 to llj. days. 2. Observations The motile period f o r the unispores and plurispores varies from a few minutes to six or seven hours. No fusion of any zoo-spores was observed. The germination and l a t e r development of both unispores and plurispores are i d e n t i c a l . Upon attachment, the spores lose t h e i r f l a g e l l a and become spherical (Fig. 6 a ,b). Subsequently, the attached, non-flagellated spores produce either d i s c o i d or filamentous plethysmothalloid germlings (Fig. 16) . -Ik-The following description of the development of discoid and filamentous plethysmothalli i s based upon several cultures of unispores i n i t i a t e d on June 20, 1963. The spores usually germinate immediately. In some instances, young discoid and filamentous plethysmothalli are distinguishable a f t e r 2k hours, since the young filaments are not as wide as the young discs nor as sharply bent to one side (compare Pig. 6c,d). At this time the plants are only one to two-celled. The eyespot i s usually not detectable by the time the plethysmothalli are two-celled (Pig. 6g). A f t e r 10 to 13 days the filaments consist of 3 to 10 c e l l s , and measure approximately kO to 80 u i n length (Pig. 6h,i). Additional growth, now takes place very rapidly, and soon a branched filament i s produced (Pig. 7a). The branches arise i n various directions from the creeping filaments, and the germlings eventu-a l l y become highly ramified. Colorless hairs are f i r s t formed from some of the c e l l s a f t e r two to three weeks (Pig. 7a). The h a i r c e l l s are narrower than other germling c e l l s and grow by means of a basal meristem. Eventualy, a dense, spherical mass of filaments r e s u l t s , the largest of which was approximately 1.75 mm in diameter a f t e r s i x weeks. The filamentous plants are e a s i l y detached, but can l i v e i n a f r e e - f l o a t i n g state. The length of the c e l l s i s usually one to three times t h e i r width and each contains- several chloroplasts and fucosan v e s i c l e s . The discs arise as l a t e r a l outgrowths from short, prostrate plethysmothalli, which vary greatly i n length (Pig. 8a,c). As described e a r l i e r , young discs may be distinguished when they -15-are one-celled, but discs are never i n i t i a t e d from a single c e l l . In most cases the discs are i n i t i a t e d at the terminal end of the elongated germling, but sometimes they are formed i n an i n t e r c a l a r y p o s i t i o n (Pig. 7g) . The formation of a disc i s usually associated with a sharp bending of the end of the plethysmothallus to one side, followed by a rapid l a t e r a l d i v i -sion of c e l l s adjacent to the bend (Pig. 8a,c). Diffuse growth then occurs, and a single-layered disc i s formed at f i r s t . Eventually the single-layered disc becomes polystromatic, due to p e r i c l i n a l d i v i s i o n s at the center of the disc (Pig. 8 g ) . Each surface c e l l contains a single nucleus and several chloro-p l a s t s . The peripheral c e l l s remain as a single layer, and the c e l l s l a t e r serve as a marginal meristem fo r l a t e r a l growth. The discs i n i t i a l l y grow very rapi d l y i n width, and a f t e r 2-1/2 months, the largest becomes 800 to 900 u in diameter. Later they do not increase as rapidly i n width as i n thickness. After f i v e months , the largest disc was 1.5 mm i n diameter (Pig. 11a). Older discs are much darker than younger ones, and resemble small R a l f s i a plants. The discoid plethysmothalli formed the i n i t i a l holdfast of the macroscopic plant, and young blades were produced from these in culture at the end of 6-1/2 months (Pig. l i b ) . The blade i n i t i a l s f i r s t appear as knob-like outgrowths from the d i s c . The knobs are m u l t i c e l l u l a r , and t h e i r c e l l u l a r d i f f e r e n t i a t i o n is s i m i l a r to those found i n nature (compare F i g . 3a*b and 12a) . The discs were also i d e n t i c a l to the young holdfasts of P. irregu-lare found i n s i t u (Fig. l l e , f ) . The blades grew very slowly i n - 1 6 -culture, and a f t e r 1 - 1 / 2 years none had developed beyond the i n i t i a l knob stage (Pig. 1 2 c ) . Intermediate plethysmothalli (partly filamentous and p a r t l y discoid) are sometimes found i n the cultures (Pig. 7 b , 9 e ) . The plant shown i n Figure 7 b was highly branched and elongated before i n i t i a t i o n of the d i s c . Several separate discs may be formed from one plant when the branches come i n close contact with the substratum, and the intervening c e l l s of the f i l a -mentous portions die (Pig. 8 f ) . The d i s c o i d portion of such intermediate plethysmothalli eventually develops into a poly-stroraatic disc, which i s the i n i t i a l holdfast of the macro-scopic plant. Blade i n i t i a l s have developed from several of the intermediate plethysmothalli. Well developed discs do not occur on unattached plethysmo-t h a l l i . Frequently, i r r e g u l a r d i s c - l i k e plethysmothalli are produced on unattached plants, but they do not develop into t y p i c a l broad, flattened discs (Pig. 9 f and 1 0 a ) . The i r r e g u l a r discs are equivalent to the "glomerules" described by Dangeard ( 1 9 6 3 a ) f o r several members of the Scytosiphonaceae. The i r r e g u -l a r discs of P. irregulare are sometimes produced along the entire length of a filament or are r e s t r i c t e d to an i n t e r c a l a r y patch. If the i r r e g u l a r discs are formed in an i n t e r c a l a r y p o s i -t i o n , they are terminated by a uniseriate thread that represents an unmodified part of the o r i g i n a l filament (Fig. 9 f , 1 0 a ) . The i r r e g u l a r disc shown in Figure 9 f was produced on an unattached four weeks old plethysmothallus from a unispore, while that -17-shown i n Figure 10a i s a similar s i x weeks old plethysmothallus. A conspicuous filamentous system i s s t i l l v i s i b l e on the l a t t e r plant. The i r r e g u l a r discs are also common i n crowded cultures, and under such conditions they are formed from any of the up-right or unattached filaments. Figure 10c shows a group of ir r e g u l a r discs from a crowded culture of eight weeks old plethysmothalli from unispores. A small portion of the same plants shown i n Figure 10c at a higher magnification (Fig. lOd) shows the i r r e g u l a r p r o l i f e r a t i o n s . If a young discoid plethysmo-thallus becomes detached from the substratum, i t may develop into an i r r e g u l a r d i s c . A l l such plants eventually develop into elon-gate, stem-like structures. In one culture maintained eight months, a knob-like i n i t i a l was produced from an i r r e g u l a r disc (Fig. 12b). The blade i n i t i a l was s t r u c t u r a l l y equivalent to that produced from an _in s i t u plant in nature (Fig. 12a) and a discoid plethysmothallus i n culture. The i n i t i a t i o n of a blade from an i r r e g u l a r disc confirms that i t i s morphologically equivalent to the di s c o i d plethysmothallus. The i r r e g u l a r disc appears to be morphologically abnormal only because i t is un-attached. In a few cultures, p r o l i f e r a t i o n s equivalent to i r r e g -ular discs were produced from filaments which were attached to t y p i c a l flattened discs. The discs and filaments are capable of reproducing themselves, both producing un i l o c u l a r and p l u r i l o c u l a r sporangia. The i n i t i a l s of the plethysmoplurisporangia are f i r s t evident upon three weeks old plethysmothalli (Fig. 13b). After four weeks, most of the -18-plethysmothalli are f e r t i l e . The plethysmoplurisporangia are produced by transverse and lo n g i t u d i n a l d i v i s i o n s of small l a t e r a l branches (Pig. 1 3 c ) ; they contain k to 55 l o c u l e s , measuring 60 to 2k0 p. long and 6 .25 to 13.0 u wide. The plethysmoplurisporangia are not always stalked, and they may be attached d i r e c t l y to the i n i t i a l filament of the disc or to the disc i t s e l f . Pigure 9b shows a s i x weeks old disc with several s e s s i l e plethysmoplurisporangia. In most instances, a greater number of these sporangia are produced on filamentous than on discoid plethysmothalli. Each locule of the plethysmoplurisporangium i s converted into a single motile c e l l . This i s l a t e r l i b e r a t e d through a terminal pore i n the sporangium, a f t e r breakdown of the p a r t i -tioning walls (Pig. 13d). The plethysmoplurispores are i d e n t i -c a l to unispores and plurispores produced on the mature laminat stage. That i s , the plethysmoplurispores have 1 to 2 chloro-p l a s t s , a single red eyespot and two l a t e r a l l y inserted f l a g e l l They are 2.2 to 3 .5 p i n diameter and k . 8 to 7.2 p. long. No fusion occurred between any of the zoospores, and i n a l l cases they germinated immediately to produce discs and filaments. A second generation of plethysmothalli was f i r s t evident i n the cultures a f t e r 35 to kO days, and they developed i d e n t i c a l l y to the f i r s t generation. Pigure 9c shows a 30 days old second generation discoid plethysmothallus, while Pigure 7d shows a s i m i l a r 15 days old filamentous plethysmothallus. Eventually the second generation produced plethysmoplurisporangia f i r s t , and then plethysmounisporangia. Several generations of plethysrao-plurispores were cultured, and each generation produced both discs and filaments. A greater, number of filaments were pro-duced upon successive generations and discs were commonly formed adventitiously from well-developed filamentous plethysmo-t h a l l i (compare with Pig. 7 b ) . Irregular discs were also common upon subculturing. Eventually^ a blade was i n i t i a t e d and i t was always associated with a d i s c . Subcultures of the plethysmothalli were maintained f o r over 2-1/2 years and were s t i l l viable and reproducing a f t e r t h i s period. Plethysmounisporangia were evident on the f i r s t generation of plethysmothalli from unispores a f t e r four to f i v e weeks. They were always produced i n fewer numbers than the plethysmo-plurisporangia. The plethysmounisporangia are ovate to oblong, and measure 35 to 57 P- long and 16 to 1+.0 u wide (Pig. li+b). They may be eithe r s e s s i l e (Pig. li+a) or subtended by a single c e l l (Pig. ll+b). The contents of the sporangium i n Figure lb,a have not been completely d i f f e r e n t i a t e d , while those i n Figure lb_b are nearly mature. The plethysmounispores are l i b e r a t e d from the terminal portion of the sporangium (Fig. lJ+e), and they are both morphologically and f u n c t i o n a l l y i d e n t i c a l to unispores, plurispores, and plethysmoplurispores, having one to two chloro-p l a s t s , a red eyespot and two l a t e r a l l y inserted f l a g e l l a . They are L L . 5 to 7.4- P- long and 2 . i i to 3 .2 u i n diameter. No fusion has been observed between the plethysmounispores, and they germinate immediately to form both discs and filaments which cannot be distinguished morphologically from the f i r s t -20 generation of plethysmothalli, nor from the various generations of plants from plethysmoplurispores. Several generations of discs and filaments have been cultured from the piethysmteuni-spores and each generation develops i d e n t i c a l l y , except that a greater number of filaments i s produced upon subculturing. Eventually, both types of sporangia were observed on each of the succeeding generations of plethysmothalli. Young blades were i n i t i a t e d on several generations of dis c s , but none be-came expanded into the t y p i c a l flattened blade. Subcultures of the plethysmothalli have been maintained f o r over 1-1/2 years„ As was stated e a r l i e r , development of unispores and p l u r i -spores i s i d e n t i c a l , and both dis c o i d and filamentous plethysmo-t h a l l i are produced from the plurispores (Fig. 16). The develop-ment of filaments after 1, 9. 17 and 38 days i s shown i n Figures 6f,j and 7e,c respectively. Figure 9d shows an intermediate plethysmothallus (partly filamentous and p a r t l y d i s c o i d ) . The development of discoid plethysmothalli can be seen i n Figures 6e, 8b,d, 9a and 11c,d. The plants are accordingly 1, 10, 12), 35» ISO and 185 days old. Irregular discs were formed on un-attached (Fig. lOe) and crowded plethysmothalli (Fig. 10b)„ Plethysmoplurisporangia were produced on both discs and filaments when they were one month old (Fig. 7c and 13f). The plethysmoplurisporangia were often produced within the remnants of old sporangia (Fig. Jf) „ In s i t u germination of the plethys-moplurispores occurred as well (Fig. 13e). Plethysmounispor-angia were produced on both discs and filaments when they were fi v e to s ix weeks old (Fig. 7f and lk c , d ) . Both types of - 2 1 -reproductive organs were morphologically equivalent to those found on the plethysmothalli from unispores„ Several generations of plethysmoplurispores and plethysmounispores were cultured and a l l developed i n the same way as the unispores and plurispores„ Young blades (knobs) were i n i t i a t e d from several of the discs of each generation of piethysmothallio -22-C, F i e l d Studies 1. Methods F i e l d observations were made to compare the growth and occurrence of various stages i n nature with those observed i n the laboratory. Several approaches were used: (1) a number of habitats of P. irregulare were denuded, and the successional development of plants was recorded; (2) cultured germlings were transplanted into the f i e l d ; (3) various objects were placed i n the f i e l d f o r the establishment of young germlings. Denuded transects were prepared at Glacier Point on February 20, March 29? and A p r i l 26, 1963. The transects were denuded by removing the larger plants and animals with a putty knife, and then burning of f the rest of the organisms with a torch. The f i r s t two tran-sects were denuded p r i o r to the period when P_. irregulare was a c t i v e l y producing zoospores. Several slides with attached plethysmothalli were transplanted into the f i e l d . Figure 21e shows the s l i d e holder used i n the f i e l d . The f i r s t transplant was made on September lij., 1963* and subsequent transplants were made on December 1, 1963 and again on January 12, 1961+. The plethysmothalli used f o r the f i r s t transplant were three weeks old, those f o r the second, f i v e days old, and those f o r the t h i r d , two weeks old. A l l of the plants were produced from the second or th i r d generation of plethysmounispores. Several objects (boards, bottles) were placed i n the f i e l d during March, May and June 1963 f o r the establishment of young germlings. - 2 3 -2. Results Tables I I , I I I , and IV summarize the sequence of events on the three denuded transects. No plants of P. irregulare could be p o s i t i v e l y i d e n t i f i e d u n t i l l a te November (Transect #2, Table I I I ) . At t h i s time, young discs were v i s i b l e which were indistinguishable from those grown i n culture. Similar discs were also evident on the f i r s t and t h i r d transects during Decem-ber (Tables II and IV)„ At each observation of a transect several scrapings were taken and examined microscopically to i d e n t i f y the d i f f e r e n t plant materials. No filamentous plethys-mothalli comparable to the ones i n culture were ever found. The discs grew very r a p i d l y and usually underwent extensive l a t e r a l growth before a blade was i n i t i a t e d . On December 29, the largest of the discs on the t h i r d transect (Table IV) was about 2 cm i n diameter and no blades were evident. No discs were v i s i b l e on the same transect on December 1, 1963. By Decem-ber 29, several of the young discs on the second transect had already produced young blades (Table I I I ) . Others had not, and were well over 13 cm i n diameter. The additional growth of the plants on the transects can be followed i n Tables II, III and IV. In a l l cases, development of the blades was s i m i l a r to that des-cribed before (Pig. 3 a ,b). At the end of A p r i l , some of the blades had become f e r t i l e , so that complete development from a microscopic disc to a f e r t i l e plant took approximately 5-1/2 to 6 months. The f i r s t transplant of s l i d e s with attached plethysmo-t h a l l i was completely unsuccessful, f o r a l l of the plants -2LL-became detached from the sli d e s a f t e r two weeks. Subsequent transplants were thereafter made on clay slides which had been del i b e r a t e l y ridged or impregnated with sand to make the surface rough. The second transplant was more successful than the f i r s t , but s t i l l many of the plants were lo s t a f t e r 17 days. A micro-scopic examination of the sl i d e s at this time (December 18, 1963) showed that almost a l l of the transplanted plethysmothalli had developed into d i s c s , while those maintained i n the laboratory were mostly filamentous. The discs growing in the f i e l d were at least lj.00 to 500 u i n diameter, whereas the largest of the c u l -tured discs were 150 to 180 u i n diameter. By January 29, the plants growing i n the f i e l d were 1.5 to 2 , 0 cm i n diameter, and had begun to i n i t i a t e young blades. Their counterparts i n the laboratory were 31+0 to 500 p. i n diameter, and had not begun to produce young blades. None of the transplanted s l i d e s could be found at the next observation on February 17* 1961+, because the sli d e holder had become dislodged and l o s t . The plethysmothalli used f o r the t h i r d transplant were also l o s t at thi s date, and were only observed once on January 29, 1961+. By thi s time many of the plants had already been l o s t , and only discs were v i s i b l e , the majority of which were 620 to 660 u i n diameter. Thus, although both discs and filaments were set out o r i g i n a l l y , a l l of the filaments were lo s t a f t e r a short time. Both types of plethysmothalli were s t i l l present on the corresponding s l i d e s growing i n the laboratory, and the largest of the cultured discs were 330 to 370 u . -25-Several attempts x>iere made to recover the young germlings of P. irregulare from objects set into the f i e l d , but they were only recovered once, on December 29, 1963. On this date, sev-e r a l young discs were found growing upon a bottle which had been placed i n the f i e l d i n early March, 1963, and had been buried i n sand from at lea s t June 23, 1963 to November 17, 1963. The bottle was examined on November 17, but no plants were v i s i b l e u n t i l the next observation on December 29. Several discs s i m i l a r to the cultured ones were found on the l a t t e r date; the largest was 1.7 cm across, and the smallest was 100 u across. The development of germlings on various portions of the bottle was followed f o r several months i n the laboratory. Young blades were i n i t i a t e d from only two discs but did not develop any further. The gen-er a l i z e d l i f e h i s t o r y of P. ir r e g u l a r e , incorporating culture and f i e l d observations, i s shown i n Pigure 16. -26-D. D i s c u s s i o n o f M o r p h o l o g y a n d L i f e H i s t o r y M o s t m e m b e r s o f t h e b r o w n a l g a e , e x c e p t f o r t h e F u c a l e s , , h a v e a n a l t e r n a t i o n o f a h a p l o i d g a m e t o p h y t e a n d a d i p l o i d s p o r o p h y t e g e n e r a t i o n . T h e s p o r o p h y t e u s u a l l y p r o d u c e s u n i -l o c u l a r s p o r a n g i a , w h i c h h a v e b e e n s h o w n t o b e t h e s i t e o f m e i o s i s i n d i v e r s e g e n e r a ( F r i t s c h , 1945) <> A c c o r d i n g t o F r i t s c h (194-5)? t h e r e i s n o g o o d e v i d e n c e t o s u g g e s t t h a t a r e d u c t i o n d i v i s i o n c a n o c c u r a t a n y o t h e r s t a g e o f t h e l i f e h i s t o r y . " * " T h e h a p l o i d z o o s p o r e s g e r m i n a t e i m m e d i a t e l y t o p r o d u c e a g a m e t o -p h y t e g e n e r a t i o n , a n d t h e d i p l o i d g e n e r a t i o n i s l a t e r r e i n s t a t e d b y t h e f u s i o n o f g a m e t e s . T h i s g e n e r a l i z e d t y p e o f l i f e h i s t o r y h a s b e e n v e r i f i e d f o r s e v e r a l g e n e r a o f b r o w n a l g a e : A s p e r o -c o c c u s b u l l o s u s ( K n i g h t , B l a c k l e r a n d P a r k e , 1935)» P h l o e o s p o r a b r a c h i a t a ( M a t h i a s , 1935)* M e s o g l o i a v v e r m i c u l a t a ( P a r k e , 1933) 9 a m o n g o t h e r s . Some m e m b e r s o f t h e b r o w n a l g a e b e s i d e s t h e F u c a l e s d o n o t h a v e a n a l t e r n a t i o n o f g e n e r a t i o n s , a n d t h e m a c r o s c o p i c p l a n t s ( " s p o r o p h y t e s " ) a r e p r o d u c e d d i r e c t l y f r o m t h e g e r m l i n g s o f t h e u n i l o c u l a r s p o r a n g i a . T h i s t y p e o f l i f e h i s t o r y h a s b e e n r e -f e r r e d t o b y F r i t s c h (194-5) a s a " d i r e c t t y p e " o f d e v e l o p m e n t , b e c a u s e t h e m a c r o s c o p i c p l a n t s a r e f o r m e d w i t h o u t t h e p r o d u c t i o n o f a g a m e t o p h y t e g e n e r a t i o n . T h e l i f e h i s t o r y o f P h a e o s t r o p h l o n i r r e g u l a r e i s o f t h e d i r e c t t y p e o f d e v e l o p m e n t , a n d t h e b l a d e s c a n a r i s e e i t h e r i m m e d i a t e l y o r a f t e r a s u c c e s s i o n o f g e r m l i n g s . " " 1 * K n i g h t (1923) c l a i m s t o h a v e f o u n d t h e h a p l o i d n u m b e r o f c h r o m o s o m e s i n t h e l a s t d i v i s i o n o f t h e p l u r i l o c u l a r s p o r a n g i u m o f P y l a i e l l a l i t o r a l i s . -27 = T h e f o l l o x f i n g s p e c i e s o f b r o w n a l g a e a l s o h a v e a d i r e c t t y p e o f d e v e l o p m e n t ; A d e n o c y s t i s u t r i c u l a r i s . ( B a y l o r , 1955), A s p e r o -c o c c u s c o m p r e s s u s ( R e i n k e , 1878; S a u v a g e a u , 1929); C h ^ r d a r i a  f l a g e l l i f o r m i s ( K o r n m a n n , 1 9 6 2 ) ; D i c t y o s i p h o n c h o r d a r i a ( F ^ y n , 193k) ; E l a c h i s t a f u c i c o l a ( K y l i n , 1937i B l a c k l e r a n d K a t p i t i a , 1963)) E l a c h i s t a s t e l l a r i s ( K y l i n p 1937); E u d e s m e z o s t e r a e ( F / y n , 193k£ K y l i n , 1933); G i f f o r d i a f u s c a t a ( K o r n m a n n . , 195k) ; H a p t e r o p h y c u s c a n a l i c u l a t a ( H o l l e n b e r g , 1 9 k l ) ; M e s o g l o i a v e r m l c u -l a t a ( K y l i n , 1937); P e t a l o n i a z o s t e r i f o l i a ( D a n g e a r d , 1963a a n d 196k); P u n c t a r i a l a t i f o l i a ( D a n g e a r d , 1963b); P y l a i e . H a l i t o r a l l s ( D a m m a n , 1930); P y l a i e l l a f u c i c o l a ( K y i i n 3 1937); a n d S t r l aria. a t t e n u a t a ( K y l i n , 193k) . K y l i n (1937) h a s a l s o i n t e r p r e t e d H y g e n ' s c u l t u r a l f i n d i n g s w i t h S p h a e o r o t r i c h i a d i v a r a c a t a (193k), i n a s i m i l a r w a y . T h e g e r m l i n g s o f A s p e r o c o c c u s c o m p r e s s u s < , D i c t y o s i p h o n c h o r d a r i a , E l a c h i s t a f u c i c o l a a n d S t r i a r i a a t t e n u a t a w e r e s t e r i l e , E l a c h i s t a s t e l l a r i s a n d G i f f o r d i a f u s c a t a b o r e b o t h u n i l o c u l a r a n d p l u r i l o c u l a r s p o r a n g i a ; t h e r e s t b o r e o n l y o n e t y p e of r e p r o -d u c t i v e o r g a n . T h e g e n e r a l i z e d l i f e h i s t o r y o f E l a c h i s t a s t e l l -a r i s a n d G i f f o r d i a f u s c a t a i s s i m i l a r t o t h a t o b s e r v e d f o r P h a e o s t r o p h i o n i r r e g u l a r e . I t i s d o u b t f u l I f t h e p r e s e n c e or* a b s e n c e o f r e p r o d u c t i v e o r g a n s i s v e r y s i g n i f i c a n t , f o r i n P„ i r r e g u l a r e t h e i r o c c u r r e n c e i 3 f o r t u i t o u s , P r i t s c h (19k5) s u g g e s t s t h a t t h e f e r t i l i t y o f s u c h g e r m l i n g s i s p r o b a b l y a r e f l e c t i o n o f t h e i r c u l t u r e c o n d i t i o n s . I n t h e c a s e o f P_„ i r r e g u -l a r e , n o p l e t h y s m o u n i s p o r a n g i a w e r e f o u n d o n a n y of t h e u n i s p o r e g e r m l i n g s c u l t u r e d i n 1962, b u t i n 1963 a n d 196k b o t h -28-plethysraounisporangia and piethysmoplurisporangia occurred. The d i r e c t type of development i s usually interpreted as re s u l t i n g from a suppression of meiosis i n the unil o c u l a r spor-angia (Kylin, 19335 F r i t s c h , 1914-5K If thi s i s true, the germ-li n g s of P. irregulare produced from unispores should be d i p l o i d . On the other hand, i f a reduction d i v i s i o n does occur, then the germlings should be haploid and parthenogametic. Unfortunately, no c y t o l o g i c a l information i s available at this time concerning the nuclear d i v i s i o n i n the unil o c u l a r sporangia, but i n d i r e c t evidence supports the former hypothesis. Foremost i s the fact that the laminate thallus i s i n i t i a t e d d i r e c t l y from the disco i d germlings produced from unispores. The germlings from both u n i -spores and plurispores of P. irregulare are plethysmothalli, representing juvenile stages of the plant that reproduce them-selves as well as i n i t i a t i n g the laminate t h a l l u s . F r i t s c h (19l4.2> 1914-5) has emphasized the fac t that the plethysmothalli of brown algae must be d i p l o i d , f o r they are capable of i n i t i a t -ing the macroscopic "sporophyte generation." Secondly, the occurrence of plethysmounisporangia and plethysmoplurisporangia on germlings from unispores suggests that such germlings are d i p l o i d . K y l i n (1933)* Svedelius (1928) and others have empha-sized that u n i l o c u l a r sporangia can occur only on d i p l o i d plants. T h i r d l y , the fact that the unispores and plurispores develop i d e n t i c a l l y suggests that they are both part of the same gener-ation, i . e . both are d i p l o i d . Although no gametophytes were observed in culture, i t does not exclude the p o s s i b i l i t y that they may occasionally exist i n - 2 9 -nature. Thus, a reduction d i v i s i o n might occur i n some of the unilo c u l a r sporangia and not i n others. Hollenberg (I9I4.I) states that meiosis f a i l s to take place i n some un i l o c u l a r sporangia of Hapterophycus cana l i c u l a t a , while i n others i t does occur. Dangeard (1963a) suggests that a similar condition might occur i n some of the plethysmounisporangia of Petalonia  z o s t e r i f o l i a . There i s no proof that this condition exists i n Phaeostrophion i r r e g u l a r e. The dir e c t development of germlings of P. irregulare from unispores could be explained by a fusion of haploid unispores, f o r there are diverse records reporting t h e i r fusion i n other brown algae (Abe, 1935a,b, 1938; Caram, 1957; C l i n t , 1927; Knight, 1923, 1929; Knight and Parke, 1931; Knight, Blackler and Parke, 1935; Schussnig and Kothbauer, 1931+). K y l i n (1933, 1937) has interpreted a l l such cases as examples of f a l s e fusions due to incomplete separation of the zoospores. He further states that none of the investigators has followed the development of the supposed "zygotes." P r i t s c h (19l|-5) appar-ently believes that such fusions can occur, f o r he interprets them as instances of extreme reduction of gametophyte to the spore. Caram (1957) reports she was able to follow the devel-opment of zygotes formed from unispores of Cylindrocarpus  b e r k l e y i . Ten to f i f t e e n percent of the spores were observed to copulate, r e s u l t i n g i n new macroscopic plants morphologically i d e n t i c a l to those that produced unispores. It i s possible that the unispores of some brown algae may fuse, but this has not been observed i n P_. irregulare. Thus, i t would not seem to be - 3 0 -a plausible explanation f o r the direct development found i n P. irregulare, F r i t s c h (19k£) states that there i s a tendency towards the elimination of the gametophyte generation i n the brown algae. This i s substantiated by an increasing number of species known to have a "direct type" of development. Dangeard's (1963a, 196k) discovery of plethysmounisporangia with Petalonia z o s t e r i -f o l i a also confirms this trend. Previously, the macroscopic t h a l l i of Petalonia and of a l l the other members of the Scyto-siphonaceae (sensu Hauck, 1883) , were not known to have any reproductive structures other than p l u r i l o c u l a r sporangia. The discovery of plethysmounisporangia on P_. z o s t e r i f o l i a i n -fers that the same structures may have been suppressed i n other members of the family. It is i n t e r e s t i n g to note that Dangeard (1963a, 196k) also found a "direct type" of development f o r the pie thy smounisp ores of P_. z o s t e r i f o l i a . According to F r i t s c h (19k5) the tendency f o r reduction of the gametophyte stiage can be demonstrated i n the Laminariales, Although the female gametophytes i n members of this order are usually rather extensive, they are sometimes reduced to a single c e l l (Arthrothamnus b i f i d u s , Kanda, 1936; Egregia menziesii, Myers, 1928; Laminaria cloustoni, Sauvageau, 1918; Macrocystis  p y r i f e r a , Levyns, 1933J Neushul, 1963; Saccorhiza bulbosa, Sauvageau, 1918). F r i t s c h (19k5) intimates that t h i s is the simplest type of gametophyte known i n the brown algae, and i t s discovery has played a considerable role i n interpreting the l i f e cycle of the Fucales. Even so, within the Fucales, which -31-do not have an al t e r n a t i o n of m u l t i c e l l u l a r generations, meiosis may be suppressed. E l l i o t and Moss ( 1 9 5 3 ) state that the eggs of Halidrys siliquo3a are parthenogenetic and no meiosis occurs i n t h e i r gametangia. The greater tolerance and p o t e n t i a l i t i e s of the d i p l o i d generation may explain the tendency toward re-duction of the gametophyte generation i n the brown algae, a trend that has also occurred i n the vascular plants. The phenomenon of heteroblasty i s a very i n t e r e s t i n g one. Sauvageau (192l|.) believes that the form of the germlings i s independent of external conditions. Naylor (1955) suggests there i s a d e f i n i t e i n d i c a t i o n that the form of both types of germlings i n Adenocystis u t r i c u l a r i s i s determined by external conditions, since cultures grown in running seawater become predominantly or exclusively discoid, whereas those l e f t i n small containers remain filamentous. In one series of small containers, a few discs were produced aft e r 29 days. Naylor f e l t that the conditions were not s u f f i c i e n t l y controlled to know exactly what was promoting the disc formation in the running seawater. Transplant studies of P_. irregulare indicated that exter-nal conditions influence the type of plethysmothalli produced. A l l of the young plants set out on s l i d e s (second transplant experiment) became predominantly d i s c o i d , while t h e i r labora-tory counterparts remained mostly filamentous. The transplanted plethysmothalli i n i t i a t e d discs e a r l i e r and were less f i l a -mentous than t h e i r laboratory counterparts. The discs remained attached better than the filaments, and i t was concluded that -32-the discs would survive better i n nature. Sauvageau (192ka) states that a s i m i l a r s i t u a t i o n exists f o r Cladosiphon zosterae. He f e e l s that germling v a r i a b i l i t y i s of some ec o l o g i c a l s i g n i -ficance, and that filamentous forms are ephemeral germlings cap-able of a more rapid and precocious reproduction than the d i s c s . K y l i n (1933) intimates that such filaments may not ex i s t i n nature. F i e l d studies of P. irregulare tend to substantiate t h i s , but i t has been impossible so f a r to prove. No filaments were observed i n denuded or In s i t u areas, but young discs were con-s i s t e n t l y found i n a l l of these areas. Heteroblasty i n P. irregulare i s no doubt related to the attachment of plethysmothalli, as no t y p i c a l , flattened disc has been found on an unattached plethysmothallus. K y l i n (1933) re-ports s i m i l a r differences between attached and unattached germ-lin g s of several brown algae. He further states that the r a p i d i t y with which the spores attach to the substratum influences the type of plant produced. Those spores which attach themselves immediately w i l l produce dis c s , while those which are loosely attached w i l l form filaments. He records several species which exhibit heteroblasty, and with each no discs are formed from f r e e - f l o a t i n g or crowded germlings. With P. irregulare only i r r e g u l a r discs were formed on unattached or crowded plethysmo-t h a l l i . A lack of space does not always i n h i b i t the formation of a disc i n a heteroblastic species, as shown by Naylor (1955) who found discs of Scytosiphon lomentaria and Adenocystis  u t r i c u l a r i s on s l i d e s which were densly crowded. - 3 3 -According to Sauvageau (192l+a), the incomplete attachment of the spore of Cladosiphon zosterae can cause the production of intermediate germlings. In such a case, the attached portion of the spore w i l l usually broaden araoeboidly into a d i s c , and the unattached part w i l l form a filament. He considers the discs and filaments to represent the extremes of development of the same spores. In some cases, the spores germinate d i r e c t l y into discs (Ascocyclus o r b i c u l a r i s , Cladosiphon zosterae t Myrio-nema vulgare, K y l i n , 1933). Sauvageau (192iLa) states that the direct development of a spore into a disc i s an example of ac c e l -erated embyrogeny, and that the production of a filament probably preceded the formation of a disc i n the evolutionary development of these species. The filaments of Cladosiphon zosterae are ephemeral and precociously f e r t i l e . No spores of P_. irregulare were found to have t h i s accelerated embryogeny, but there was a tendency f o r the d i s c o i d a l plethysmothalli to have fewer repro-ductive organs than the filamentous plethysmothalli. As discussed e a r l i e r , i n a few cultures the t y p i c a l , flattened discs of P_. irregulare were found to produce i r r e g u l a r discs from filaments which were attached to the flattened discs. Doty (I9I4.7) appears to have found si m i l a r structures i n nature, because i n a few specimens (M.D. #1+001) rhizome-like protrub-rances were evident from the portion of the stipe just above the holdfast. -3k-IV. AUTECOLOGY OP PHAEOSTROPHION IRREGULARE AT GLACIER POINT, BRITISH COLUMBIA Regular f i e l d studies were made from 1961 to 196k at Glacier Point, where the growth and occurrence of P_. irregulare were studied i n r e l a t i o n to environmental f a c t o r s . A. Methods In the v i c i n i t y of Glacier Point there i s an annual cycle i n which sand i s regularly deposited and removed. A record of sand f l u c t u a t i o n was made at f o r t n i g h t l y to monthly inter v a l s from June to December, 1963. The sand lev e l s were determined by stretching a taut l i n e between two conspicuous boulders that were above any sand. The v e r t i c a l heights of the boulders above the t i d a l datum l e v e l were recorded, and these rocks were used as a basis f o r reference measurements. The heights from the top of the sand to the l i n e were measured at two-foot i n t e r v a l s . After the sand subsided, p r o f i l e s of the d i f f e r e n t transects were determined i n d e t a i l at one-foot i n t e r v a l s . A photographic record of sand f l u c t u a t i o n at Glacier Point was made i n 1963 and 196k. With the help of the Canadian Hydrographic Service, an attempt was made at Glacier Point to establish a continuous t i d a l recording instrument (Ottboro), but thi s f a i l e d because of extreme surf action. A l l t i d a l information used i n t h i s study was obtained from two sources: The Canadian Hydrographic Service Tide and Current Tables f o r 1963 and 196k (Anon. 1962c, 1963), and the hourly coordinates of tide gauge readings recorded at Sooke from March 1958 to March 1959. No other t i d a l gauge - 3 5 -readings are available f o r the v i c i n i t y of Glacier Point. The height of tides at "Glacier Point was calculated by applying a standard 0 . 3 - f o o t correction f a c t o r f o r the predicted ( 1 9 6 3 , 1 9 6 k ) and recorded ( 1 9 5 8 * 1 9 5 9 ) l e v e l s at Sooke. Water temper-atures were taken by immersing a thermometer in water samples drawn by bucket from the surface of the water. Readings were made only during f i e l d observations at low tides, the hour of which varied throughout the year. Although the readings were only made one to three times per month, they are taken as a representation of variations at the l o c a l i t y . The water temper-ature i n a l l instances represents three or more measurements. Daily surface water temperatures from Neah Bay, Washington (Anon. 1 9 6 2 a ) were also compared with the temperatures recorded from Glacier Point. The data from Neah Bay probably gives a close approximation of the conditions at Glacier Point. S a l i n i t i e s recorded from June 1 9 6 3 to February 2 6 , 1 9 6 k were determined with a s p e c i f i c gravity hydrometer, and from March to July 1 9 6 k , by conductivity measurements. In the former period, the s a l i n i t y values represent the average of three hydrometer readings. A l l water samples were drawn by bucket from the surface. The d a i l y surface water s a l i n i t i e s at Neah Bay (Anon. 1 9 6 2 a ) were compared with the values recorded at Glacier Point. The method of Murphy and Riley ( 1 9 6 2 ) was used to measure the reactive phosphorus (phosphate), and the soluble n i t r a t e was recorded using the method of Mullen and Ri l e y ( 1 9 5 5 ) . The values represent duplicate determinations and are expressed as ug-at / 1 . The samples used f o r nutrient determinations were collected from the surface i n 5 0 0 cc polyethylene bottles and were frozen i n dry ice within one hour a f t e r c o l l e c t i o n . Values f o r p r e c i p i t a t i o n and a i r temperatures were obtained from records f o r Jordan River, which i s about four miles west of Glacier Point (Anon. 1962b). The v e r t i c a l l e v e l s of P. irregulare and several other a s s o c i -ated plants were determined using the procedure of Widdowson (1959). A l i n e was sighted from the horizon to a conspicuous marker (pole, rock, e t c . ) , and a plumb-line was dropped to the l e v e l to be meas-ured. The l e v e l (height) was related to the reference mark, which i n turn was related to the sea l e v e l at a s p e c i f i c time. The average of three measurements was used for each l e v e l determined. A l l of these measurements were related to two primary reference marks, the heights of which were determined on several occasions by measuring from t h e i r top surface to the seawater. The time was then noted and the heights of the reference marks were re-lated to the predicted t i d a l l e v e l . In a few instances, f o r ease of l e v e l i n g , secondary reference points were established from the primary one. The growth of several populations of J?. irregulare at Glacier Point was studied during 1962 to 1963 and 1963 to 196I+. A small portion of the population (holdfast area about 5 era ) was collected and preserved u n t i l measurements were made. The growth of the plants was expressed i n two d i f f e r e n t ways; 2 (I) fresh weight of the blades/m , (2) length of the blades. Both methods gave comparable r e s u l t s . The plants were weighed -37-a f t e r being surface-dried. The holdfasts of the macroscopic plants were excluded from the weights because they were con-sidered too variable. The blades used i n the measurements were cut off the holdfast at the base of t h e i r stipe. The weight of the blades per unit area of the sample was converted to the weight/m^. The lengths of a l l t h a l l i from a sample were deter-mined, and either t h e i r average length, or the percent frequency of d i f f e r e n t size classes was calculated. The seasonal p e r i o d i -c i t y of reproduction during 1963 was determined by microscopi-c a l l y examining 100 blades from each c o l l e c t i o n . 3 8 -Bo Environment 1„ Sand Fluctuation Two basic marine habitats are present i n the v i c i n i t y of Glacier Point - sandy and rocky,, Figure 17 shows the general d i s t r i b u t i o n of sand i n late summer 1963. In a l l instances, i t i s r e s t r i c t e d to embayments, while adjacent points are de-void of sand 0 Irregular fluctuations occur at any time of the year, but there i s an annual cycle i n which sand i s regularly deposited and removed0 The largest deposition occurs i n the late spring and summer (Fig, 18 - 2 0 ) ; i t p e r s i s t s u n t i l the fir-Bt winter storm„ approximately November to December., During this l a t t e r period i t may be removed completely i n less than 2k hours., leaving the underlying rocks exposed again 0 This c y c l i c f l u c t u -ation has been observed f o r at least 11 years (personal communi-cation with Miss Packham, a l o c a l resident) and i s apparently a regular environmental feature of Glacier Point„ Thus, a n y per-ennial plant which grows i n such an environment must be a d a p t e d to extreme reduction i n l i g h t i n t e n s i t y , severe abrasion, and prolonged submergence I n vA, The greatest amount of sand exists on areas exposed to the greatest surf action at Glacier Point (Fig„ 17* areas k, 5s 6), whereas i n more sheltered areas (Fig„ 17s areas 1, 2) the sand i s reduced. Figure 18 shows the extreme variation i n sand l e v e l s on the exposed west side (areas 6a, 6b), -while Figure 21 shows a reduced v a r i a t i o n i n sand on the more sheltered east side (areas 1 , 2 ) „ The three locations designated as areas 6a, 6b -39-and 7 i n Figure 17 represent a series of habitats where there is a progressive reduction i n the amount of sand. Area 6a i s f u l l y exposed to the f l u c t u a t i n g sand, whereas the amount of sand i n area 6b is not as great. The reduced sand i n area 6b i s probably due to the p o s i t i o n of a reef i n front of i t , which r e s t r i c t s the onshore deposition of sand (Fig. l8a-d). In order to determine the extent of sand f l u c t u a t i o n , a record of sand l e v e l s on areas 6a and 6b was kept from June 23 to December 11, 1963 (Pig. 22, 23). Measurements showed that constant f l u c t u a t i o n occurred i n both areas. The sand cover i n 2 area 6a was present from at least June 6 to November 17, 1963. The highest sand leve l s i n the same area were recorded during September 1963. Since the v e r t i c a l d i s t r i b u t i o n of P. irregulare extends from about 1.8 to I4..6 feet above the zero t i d a l datum l e v e l (Fig. 2q_), most of the plants i n this area at [\. feet or less would have been covered from June 6 to November 17, 1963. A few populations of P. irregulare (not on p r o f i l e s measured) which were growing above ii feet were uncovered intermittently. As much as f i v e feet of sand was deposited on some of the plants f o r several months. Figures 18 and 19 show the seasonal depo-s i t i o n of sand on area 6a during 196L_. Figure 25 i l l u s t r a t e s the v a r i a t i o n i n sand d i s t r i b u t i o n i n several other extremely sandy areas where P_. irregulare grows. A conspicuous difference between the sand cover at the lower and higher lev e l s of the i n t e r t i d a l zone is evident in Figure 25. ^No p r o f i l e measurements were recorded p r i o r to June 23, 1963, but observations were made on June 6, 1963. The period of sand coverage i n area 6b during 1963 was from approximately July 20 to November 3. The maximum sand coverage was observed on October J, 1963 when the boulders at the s i x -foot l e v e l were completely buried. Most plants of P. irregulare i n area 6b were probably buried throughout the period of July 20 to November 3» 1963, Figure 20 shows the variations of sand l e v e l i n area 6b during 1963 and I96I4.. The sand l e v e l at the end of August I96I4. was much lower than that of August 1963* and area 6b was f i n a l l y covered with sand between August 18 and September II, 196L.. During 1963* a comparable amount of sand was present by July 20 (Fig. 20d). Both the amount of sand deposi-t i o n and the duration of sand coverage are greater i n area 6a than i n area 6b. This was dramatically evident i n 196Ij_ (Fig. l8a-d). Most of the sand grains are between O.II4.9 and 0.250 mm i n diameter, with a maximum percent being about 0.208 mm (Table V). According to Shepard ss (19lj-8) c l a s s i f i c a t i o n of beach types, most of the grain sizes would be intermediate between fine (0.12 mm) and medium sand ( 0 . 2 5 mm). As a r e s u l t , the beach is well drained. 2. Tides In the v i c i n i t y of Glacier Point, the tides are mixed semi-diurnal and are the r e s u l t of two component tides - the semi-diurnal, with an i n t e r v a l of about 12-1/2 hours between high waters; and the diur n a l , with an i n t e r v a l of approximately 2 5 -%and was removed approximately November 3> 1963 according to Mr. A. Packham (personal communication). - k l -hours between successive waters (Anon, 1 9 6 3 ) . Usually two low and two high waters occur per day, which may be designated respectively as lower low water (LLW), higher low water (HLW), higher high water (HHW), and lower high water ( L R W ) . Table VI shows a series of t i d a l factors which were calculated f o r each month during 1 9 6 k , i n the v i c i n i t y of Glacier Point, The t i d a l factors correspond to the c r i t i c a l l e v e l s designated by Doty ( 1 9 k 6 ) f o r the v e r t i c a l d i s t r i b u t i o n of marine algae. The aver age values f o r each month and f o r the whole year are shown In Table VI. The highest (H), lowest (L), and mean (M) values f o r each of the high and low waters are designated. The mean sea l e v e l (MSL) f o r 1 9 6 k was 6.2 feet above the zero t i d a l datum point. The lowest of the lower lows (LLLW) occurs during the day i n the summer, but during the night i n the winter (Pig. 26). A series of representative t i d a l graphs f o r the periods of lowest tides during the winter and summer of 196kare shown i n Figures 27 and 28. The maximum t i d a l amplitude (difference be-tween HHW and LLW) f o r t h i s period was 10.8 feet. Figure 26 demonstrates the number of times that various l e v e l s of P_. i r r e  lare were exposed during one growing season (November 1963 to July 196k). The values are conspicuously d i f f e r e n t from month to month. The number of daylight exposures increase rapi d l y a f t e r March. The duration of exposure f o r the d i f f e r e n t t i d a l l e v e l s (0.5 to 5.0 feet) i n 1958 to 1959 i s shown i n Figure 29; this i s the main zone in which P_. irregulare i s found. The period of exposure i s expressed as the mean number of minutes 4i2~ per day of exposure during the month. The maximum exposure periods occurred i n May to July and November to December 1958. The maximum and minimum d a i l y periods of exposure at each l e v e l ( 0 . 5 to 5 . 0 feet) from March 1958 to March 1959 are shown i n Table VII. During June, plants of P. irregulare were exposed f o r periods up to 6 .8 hours per day. 3 . Seawater Temperature Figure 30 i s a plot of surface water temperatures observed at Glacier Point. The temperatures ranged from 7.2°C to 13.3°C. Plants of P. irregulare often grow i n tide pools and are exposed to a greater f l u c t u a t i o n of temperature from 7.1 to 20°C. Such tide pools are usually warmer than the surface waters i n the summer, but cooler during winter. The average surface water tem-perature during 1963 to 196LL at Glacier Point was 10°C, and that of the tide pools was 11.8°C. A plot of the d a i l y surface water temperatures at Neah Bay from 1934- to I960 i s shown i n Figure 31. The mean temperatures at Neah Bay range from 7.4°C to 11.8°C; These values are comparable to the ones observed at Glacier Point. The maximum ( 1 7 . 8 ° C ) and minimum ( 2 . 2 ° C ) temperatures are more extreme than any of the surface values recorded at Glacier Point during 1963 to 1961i» but are not as high as the maximum tide pool temperatures (20°G). 11. S a l i n i t y Figure 32 i s a plot of surface water s a l i n i t i e s at Glacier Point. The s a l i n i t i e s ranged from 27 .5 °/oo to 32 .8 °/oo . The highest' s a l i n i t i e s were observed during A p r i l and May 196i|_. During the spring and summer the tide pool populations of P. irregulare were exposed to higher s a l i n i t i e s than the surface waters (maximum d i f f e r e n t i a l k . l °/oo), but during the winter they are exposed to lower s a l i n i t i e s (maximum d i f f e r e n t i a l 1.7 °/oo). The average s a l i n i t y of the surface waters at Glacier Point during 1963 to 196k was 31. 2 °/oo, whereas that of the tide pools was 31.7 °/oo . An analysis of the d a i l y surface water s a l i n i t i e s at Neah Bay i s shown im Pigure 33. The mean s a l i n i t i e s range from 30.5 bo 32.k °/oo and are com-parable to the values recorded at Glacier Point. The minimum values (lk.O and lk.9 °/oo) are much lower than any recorded at Glacier Point. 5. Nutrients a. Nitrates - Pigure 3k i s a plot of n i t r a t e values of the surface waters at Glacier Point. The highest concentrations were found i n December (k2 ug-at/1) and March (35 ug-at/1). The nitr a t e concentration decreased r a p i d l y after March 21, 1963, and on June 29 the lowest value (z. 1 p.g-at/1) was recorded. In the f a l l of 1963, a pronounced difference i n n i t r a t e concentra-t i o n was found between the east (area 1) and west side (area 6a) of the point (Pig. 3k). The n i t r a t e concentration of the east side was r e l a t i v e l y constant from September to March, but was much higher from September to November than the west side. In December, there was a sudden increase i n nitrate on the west side. The d i s t i n c t i o n between the two areas i s probably related to the difference i n time of nutrient s a l t regeneration from the decaying populations of algae. Many of the plants on the west - M r side were buried under sand u n t i l l ate November, whereas most of the plants on the east side were not buried under sand. A rapid decomposition of the unburied plants on the west side probably occurred a f t e r disappearance of the sand. As discussed e a r l i e r , removal of the sand cover at Glacier Point sometimes occurs very rapidly, and usually takes place during the f i r s t severe winter storm. Such, a storm might cause an upwelling of n u t r i e n t - r i c h deep water, but the fact that no other sudden increases occurred during the rest of the winter season, sug-gests that the nitrat e maximum was associated with decaying plant materials. The average n i t r a t e concentration f o r a l l the surface water samples from Glacier Point was 2 i i . l x ug-at/1 . b. Phosphates - Figure 35 is a plot of phosphate values i n the surface waters at Glacier Point. The highest phosphate values were recorded on December 1, 1963 (11.k- ug-at/1) and June 2 9 , 196l|. ( l l i . 2 ug-at/ 1 ) . The phosphate concentrations did not vary noticeably from December 18, 1963 to A p r i l 3 0 , 1961i, but thereafter they increased r a p i d l y . The high phosphate con-centration recorded on December 1, 1963 for the west side of Glacier Point, was probably also associated with nutrient s a l t regeneration from decaying populations of buried algae. The December phosphate maximum, however, occurred e a r l i e r than the December ni t r a t e maximum. On the other hand, the corresponding increase i n phosphate concentration from A p r i l 30 to June 2 9 , 196LL was not accompanied by an increase i n n i t r a t e , and the ni t r a t e minimum of June 2 9 , I96I4. (Z- 1 ug-at/1) corresponded to the phosphate maximum ( l k . 2 ug-at/1) of the same da t e , ^ The d i f f e r e n t i a l occurrence of n i t r a t e and phosphate d u r i n g Decem-ber 1963 and June 196k suggests that there may be e i t h e r a f a s t e r r e g e n e r a t i o n of phosphate than n i t r a t e , or a more r a p i d u t i l i z a t i o n of n i t r a t e than phosphate„ The former seems more p l a u s i b l e , but the i n f o r m a t i o n a v a i l a b l e i s not adequate t o d i s t i n g u i s h the mechanism i n v o l v e d . The average phosphate con-c e n t r a t i o n f o r a l l s u r f a c e -water samples taken at G l a c i e r P o i n t was 2„2 ug-at/1 „ However, there' was a wide range of values (0.73 to Ik.2 ug-at/1) . 6. M e t e o r o l o g i c a l J3 and i t i on s The average p r e c i p i t a t i o n at Jordan R i v e r , near G l a c i e r P o i n t , i s 75.99 inches per ye a r , and about one percent occurs as snow ( P i g . 36) , The maximum r a i n f a l l , occurs d u r i n g the winter, and i n November, 1962 over 22 inches were recorded. On the average, o n l y 1-1/2 to 2-1/2 inches o f r a i n f a l l occur per month d u r i n g June to August, The mean monthly a i r temper-atures at Jordan R i v e r d u r i n g 19k6 to 1962 ranged from about 3°C to l k . 5 ° G , and the average temperature f o r the same p e r i o d was 8,9°C ( P i g . 37) . The maximum and minimum temperatures r e c o r d e d d u r i n g 1962 were 23.9°C and -7o7°C, whereas the h i g h -est and lowest temperatures recorded d u r i n g 19k6 to 1962 were o 31.1 and -15»5 G, r e s p e c t i v e l y . The c o r r e s p o n d i n g values of n i t r a t e and phosphate on a p a r t i c u l a r date are taken from the same sample. -46-C. Occurrence of P. irregulare and Other Algae Regular f i e l d observations at Glacier Point indicate that there i s a pronounced influence of sand upon the d i s t r i b u t i o n and growth of P. irregulare . Such i s also the case i n other areas where i t has been observed (Pig. 1 ) . At Glacier Point, P. irregulare i s r e s t r i c t e d to rocks i n sandy areas (Fig. 1 7 ) . The greatest number of plants occur where gross fluctuations of sand take place annually (Fig. 1 7 , areas k-6; F i g . 1 8 , 1 9 , 2 0 ) , and fewer plants occur where small fluctuations of sand occur annually (Fig. 1 7 , areas 1 , 2 and F i g . 2 1 ) . Most associated plants in such, sandy areas are annuals, A detailed study was made of the a l g a l associations i n areas 6a, 6b and 7 , i n order to determine the conspicuous plants found i n sandy and rocky areas at Glacier Point. The v e r t i c a l d i s t r i -butions (Fig, 2 k ) and the species composition (Table V I I I ) of the more conspicuous plants i n the three areas indicate that the al g a l associations In each are very d i f f e r e n t . Figure 38 shows a comparison of the dominant plants on the three adjoining areas. Four perennials besides _P, irregulare are common i n area 6a -Ahn f e l t i a concinna. A. p l i c a t a , Gigartina p a p i l l a t a , and Gymno-gongrus l i n e a r i s . Several other perennial plants are present, but they have a very limited d i s t r i b u t i o n . The most conspicuous of these are Heterochordaria abietina, Plocamium pacificum, Ralf -s i a fungiformis, R, p a c i f i c a , Sphacelaria racemosa, B o s s i e l l a  corymb i f era, C o r a l l i n a o f f i c i n a l i s var. c h i l e n s i s , _C. vancouveri-ensis, and P r i o n i t i s l y a l l i i . The l a s t four species are usually r e s t r i c t e d to tide pools. Figure 39e shows a tide pool con-taining several c o r a l l i n e algae and P_. ir r e g u l a r e . Three other perennials (Fucus evanescens, Endocladia muricata, and Odonthalia  floccosa) were found only on high rocks above the highest sand l e v e l s (Fig. l i l e ) . The species composition found i n area 6a i s representative of most other areas at G l a c i e r Point where large fluctuations of sand occur. Most of the zone between 1.8 to J4..6 feet i n area 6a i s domi-nated by P. irregulare, although small pockets of Gymnogongrus  l i n e a r i s and Ah n f e l t i a concinna are found above 2 feet. Figure liOa, b, e shows the t y p i c a l habitat of P. irregulare in t h i s area. In some cases A h n f e l t l a concinna can form a dense zone below 2 feet (Fig. 39a-c). Gymnogongrus l i n e a r i s is usually not as extensive as Ahn f e l t i a concinna, although i t may be l o c a l l y abundant (Fig. 39d, l i l b , LL2C). Most specimens of Gigartina p a p i l l a t a i n area 6a are higher than those of P. irregulare and occasionally the two overlap. Figure ii2d,e shows the t y p i c a l habitat of Gigartina p a p i l l a t a i n area 6a, and Figure li3c,d shows the same plant i n a comparable area s l i g h t l y to the north. P. irregulare is very conspicuous i n the region north of area 6a (Fig. k3>e) • The deposition of sand i n the l a t t e r area between May lk and June 26 can be seen i n Figure ii3a,b. In the f i e l d i t i s often d i f f i c u l t to distinguish between young plants of Gigar-t i n a p a p i l l a t a and those of P. irre g u l a r e. In a few l o c a l i z e d areas (sloping sand substrates or sand-covered rocks) the surface is s t a b i l i z e d by a sand-binding community of Sphacelaria racemosa and a c o l o n i a l diatom Amphipleura sp. (Pig. 39d). Eventually, a number of other plants w i l l grow on the s t a b i l i z e d sand, but P. irregulare grows only on a rocky substrate. Although Doty (19i|-7) states that i t was occasionally epiphytic on other plants along the Oregon coast, t h i s has not been confirmed by my observations. Even though the rocky outcrop i n area 6 a from about 2.0 to Ii.5 feet i s almost completely dominated by P_. irregulare , t h i s i s not the case i n area 6b (Table VIII and F i g . 38). During the early spring and summer a greater variety and number of plants are present i n the l a t t e r area. The most conspicuous plants are A l a r i a marginata, C o r a l l i n a vancouveriensis, Monostroma  oxyspermum, Porphyra perforata, _P. irregulare , and Spongomorpha  c o a l i t a . A mixture of other small forms is also evident (Table VIII). Apparently more plants l i v e i n area 6b because of the less severe environmental conditions. Figures 18 to 20 show the ex-treme differences of sand f l u c t u a t i o n i n areas 6 a and 6 b . Figure Lj.0c,d shows the general habitat of area 6 b . A detailed transect of the two areas ( 6 a , 6 b ) was made between 1 to 5 feet, and the abundance of d i f f e r e n t plant species was determined. The r e s u l t s , calculated as density, are summarized i n Table IX. Several species are much more abundant i n area 6b than in area 6 a , the most s t r i k i n g example being Spongomorpha c o a l i t a . The corresponding levels (1 to 5 feet) on area 7 (Pig. 17) are occupied by an e n t i r e l y d i f f e r e n t plant community. The most conspicuous plants are Phyllospadix s c o u l e r i , Hedophyllum s e s s i l e , G-igartina p a p i l l a t a , Callithamnion pikeanum, and A l a r i a marginata, but a few specimens of G l o i o p e l t i s furcatus, Fucus evanescens, -k9-and Endocladia muricata may also be present. The raid-intertidal to high i n t e r t i d a l (5 to 11 feet) i s dominated by a completely d i f f e r e n t community of plants than in areas 6a or 6b. The most conspicuous plants are Fucus evanescens. Odonthalia floccosa, Gigartina p a p i l l a t a , Leathesia difformis. Endocladia muricata. and G l o i o p e l t i s furcatus (Fig. 3 8 ) . Figure kl|.a-d show the gen-e r a l habitat of the area and the most conspicuous plants. The lower i n t e r t i d a l to subtidal have a much greater va r i e t y of Laminariales than db any of the sandy areas. Since the sandy areas undergo constant f l u c t u a t i o n , i t i s not surprising that c h a r a c t e r i s t i c communities are found here. There i s a gradual reduction i n the number of species from a rocky to a sandy habitat, and t h i s can be noted in areas 6a, 6b and 7 (Table VIII). A perennial plant growing in a sandy area must be able to with-stand constant abrasive action as well as prolonged submergence i n sand. Besides P_. irr e g u l a r e , only two perennials are appar-ently r e s t r i c t e d to sandy areas - A h n f e l t i a concinna and Gymno-gongrus l i n e a r i s . Gigartina p a p i l l a t a seems to grow more abundantly i n predominantly sandy areas, but i t may also extend into rocky areas, Sphacelaria racemosa may be r e s t r i c t e d to sandy areas at Glacier Point, but because of i t s small size i t may have been overlooked. A few perennial plants, such as Fucus evanescens, Endocladia muricata, and Odonthalia floccosa may also extend into the sandy areas, but they are r e s t r i c t e d to rocks above the sand (Fig. 38, k l ) . Several species are consistently absent i n a l l sandy areas - Laminaria s e t c h e l l i i , Leathesia difformis, Cladophora trichotoma, C o l l i n s i e l l a tuberculata, Monostroma z o s t e r i c o l a , Callithamnion pikeanum, C a l l o p h y l l i s crenulata, Erythrophyllum delesserioides, Gloio-p e l t i s furcatus, Grateloupia c a l i f o r n i c a , Hymenena f l a b e l l i g e r a , Pikea pinnata, Porphyra nereocystis, Pterosiphonia bipinnata, P t i l o t a hypnoides, and Smithora naiadum. Several areas at Glacier Point are covered by sand f o r seven to eight months per year, and except f o r a few scattered individuals of Gymnogongrus l i n e a r i s and A h n f e l t i a concinna, very few perennials are found there. During the period of sand subsidence, most of the substrates are completely covered by annuals, such as Enteromorpha l i n z a and Porphyra variegata (Pig. L).2a). In contrast to such extreme habitats, there are sheltered areas where l i t t l e sand i s deposited (Pig. 16, areas 1,2 and Pig. 21). These areas are also dominated by annuals, but the following perennials are sometimes present: Halosaccion  glandiforme, Laminaria s e t c h e l l i i , Odonthalia floccosa, Rhodo-mela l a r i x , and P. ir r e g u l a r e . A number of the laminariales ( A l a r i a marginata, Laminaria c u n e i f o l i a , L. s e t c h e l l i i and Ptery-gophora c a l i f o r n i c a ) grow f a i r l y well in such areas, but P. irregulare usually becomes completely overgrown by Entero-morpha l i n z a during the summer (Pig. 21d). Populations of P_. irregulare have been observed elsewhere on Vancouver Island at Box Island, near Long Beach, and Brooks Peninsula; and i n the state of Washington, U.S.A., at Ruby Beach and Cattle Point, San Juan Island. In each l o c a l i t y , P. irregulare occurs attached to rocks i n sandy areas, and the associated vegetation i s very s i m i l a r to that observed at Glacier Point. In a l l l o c a l i t i e s , Gymnogongrus l i n e a r i s  A h n f e l t i a concinna are also associated with P. irregulare - 5 2 -D. Growth and V a r i a b i l i t y of Mature Plants i n the F i e l d The growth period of P. irregulare at Glacier Point i s limited to six to eight months of the year. Growth i s i n i t i -ated a f t e r the removal of sand i n winter (approximately November), and terminates when the plants are buried in spring or early summer (approximately June). On removal of sand i n winter, only the perennial holdfasts and remnants of old blades remain (see F i g . l4-la,c,d). In some instances, the holdfast may be worn to a f r a c t i o n of i t s o r i g i n a l s i z e , but i t is s t i l l able to i n i t i a t e new blades,, These blades f i r s t appear as knob-like outgrowths from the holdfast, and develop rapidly into the t y p i c a l , flattened blades (Fig. 2, 3 a ,b). Figure 2e,f shows clusters of new blades which have developed i n two months. After three to four months, the blades are often i r r e g u l a r l y torn (Fig. 2g,h). The annual growth of P. irregulare i n several d i f - • ferent habitats (exposed, sheltered, tide pool, non-tide pool and sloping substrate) i s i l l u s t r a t e d i n Figures k5 to 53. In Figures k5 to lf7, the growth rate is expressed as grams fresh p weight of blades/m „ In a l l populations there was a rapid i n -crease i n growth from February to A p r i l , but thereafter two d i s t i n c t growth patterns became apparent. In the one case, there was a rapid decrease in growth a f t e r an early spring maximum (approximately A p r i l ) ; i n the other, the maximum period of growth occurred l a t e r (approximately May) and usually the growth rate did not decrease rapi d l y thereafter. The f i r s t type of growth-response occurred in non-tide pool plants (Fig* kOa-d),. and the - 5 3 -second, i n t i d e p o o l p l a n t s ( P i g . Ij-Oe) „ A t a c o r r e s p o n d i n g l e v e l o f the i n t e r t i d a l zone, no con-s p i c u o u s d i f f e r e n c e s were apparent between the growth o f p l a n t s f r o m exposed and s h e l t e r e d l o c a l i t i e s at G l a c i e r P o i n t ( F i g . k5t> I4.6). On the o t h e r hand, t h e r e was a tendency f o r n o n - t i d e pool p l a n t s a t a h i g h e r l e v e l t o grow more s l o w l y t h a n t h o s e a t a l o w e r l e v e l ( P i g . LL5) , a n ^ an e a r l i e r d e c r ease i n growth was noted i n the h i g h e r p l a n t s . P l a n t s growing on a s l o p i n g s u b s t r a t e showed a s l o w r a t e o f growth ( P i g . LL7). F i g u r e s 1L8 t o 53 show the g r o w t h o f P. i r r e g u l a r e e x p r e s s e d as the l e n g t h o f the b l a d e s . I n F i g u r e s I18 t o 51* growth i s shown i n a s e r i e s o f b a r diagrams t h a t i n d i c a t e the p e r c e n t o c c u r r e n c e o f d i f f e r e n t s i z e c l a s s e s t h r o u g h o u t the growing season. These d a t a are shown o n l y f o r f o u r o f the p o p u l a t i o n s , and a comparison o f the mean b l a d e l e n g t h f o r a few o t h e r p o p u l a t i o n s i s shown i n F i g u r e s $2 and 5 3 . The t i d e p o o l and n o n - t i d e p o o l p l a n t s i n i t i a l l y grew comparably, but l a t e r the p e r c e n t o c c u r r e n c e of l a r g e b l a d e s and the mean l e n g t h o f the b l a d e s was l e s s i n the n o n - t i d e p o o l p l a n t s . The mean l e n g t h o f the n o n - t i d e p o o l p l a n t s was g r e a t e s t d u r i n g March or e a r l y A p r i l , and t h e r e a f t e r I t de-c r e a s e d . Tide p o o l p l a n t s u s u a l l y a t t a i n t h e i r maximum l e n g t h i n l a t e A p r i l and May. P l a n t s g r o w i n g on a s l o p i n g s u r f a c e never grow as l a r g e ( F i g . $1$ 5 3 ) . No c o n s p i c u o u s d i f f e r e n c e was found between the growth r a t e o f s h e l t e r e d and exposed p l a n t s ( F i g . 5 2 , 5 3 ) . Under a l l c o n d i t i o n s , the t o t a l number of l a r g e b l a d e s i s v e r y s m a l l , whereas s m a l l b l a d e s are found i n abundance thr o u g h o u t the growing season ( F i g . l|.8-5l) . -5lr I n n o n - t i d e p o o l h a b i t a t s s m o s t o f t h e l a r g e r b l a d e s d i e i n l a t e s p r i n g t o e a r l y s u m m e r , l e a v i n g p l a n t s t h a t a r e m u c h s m a l l e r a n d d a r k e r t h a n t h e i r t i d e p o o l c o u n t e r p a r t s . I n s o m e I n s t a n c e s d u r i n g m i d - s u m m e r a l l t h e b l a d e s d i e a n d t h e p l a n t i s r e d u c e d t o i t s b a s a l h o l d f a s t . F i g u r e k O a - d a n d k l c , d s h o w t h e e x t r e m e 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 n o n - t i d e p o o l p l a n t s . I t I s o b v i o u s t h a t t h e m a t u r e p l a n t s o f P_. i r r e g u l a r e a r e e x t r e m e l y v a r i a b l e i n n a t u r e , a n d t h e r e i s a d i s t i n c t d i f f e r e n c e b e t w e e n t h e m o r p h o l o g y o f t i d e p o o l a n d n o n - t i d e p o o l f o r m s . On o n e o c c a s i o n ( M a y 25 . 1963) , s e v e r a l s a m p l e s o f n o n - t i d e p o o l p l a n t s w e r e t a k e n f r o m 2.2 t o 3.6 f e e t a n d c o m p a r e d w i t h a s a m p l e t a k e n f r o m a t i d e p o o l a t k . 5 f e e t . T h e m e a n l e n g t h o f 50 o f t h e l a r g e s t m a t u r e b l a d e s f r o m e a c h s a m p l e w a s d e t e r m i n e d , a n d t h e r a n g e w a s 25.5 t o 30.6 mm. F i g u r e 5k i l l u s t r a t e s t h e a b o v e m e n t i o n e d r e s u l t s . T h e l e n g t h o f t h e b l a d e s w a s f o u n d t o v a r y g r e a t l y o n a s l o p i n g s u r f a c e , a n d i n o n e s e r i e s o f s a m p l e s t h e m e a n b l a d e l e n g t h v a r i e d f r o m 10.31 t o 3k.76 mm w i t h i n a v e r t i -c a l h e i g h t o f 1 „25 f e e t ( F i g , 55)° T h i s v a r i a b i l i t y i s e v i d e n t I n F i g u r e 56f . E , S e a s o n a l P e r i o d i c i t y o f R e p r o d u c t i o n F e r t i l e p l a n t s o f P_, i r r e g u l a r e o c c u r f r o m a p p r o x i m a t e l y A p r i l t o J u l y ( F i g . 57)= M o r e p l a n t s a r e f e r t i l e f r o m J u n e t o e a r l y J u l y , a n d d u r i n g t h i s t i m e m o s t p o s s e s s u n i l o c u l a r s p o r -a n g i a . U n i l o c u l a r a n d p l u r i l o c u l a r s p o r a n g i a r a r e l y o c c u r a t t h e s a m e t i m e o n t h e s a m e t h a l l u s . P l u r i l o c u l a r s p o r a n g i a u s u a l l y o c c u r e a r l i e r i n t h e s e a s o n . T h e s e a s o n a l p e r i o d i c i t y o f r e p r o d u c t i o n m a y p a r t i a l l y e x p l a i n w h y p l u r i l o c u l a r s p o r a n g i a w e r e n o t r e c o r d e d e a r l i e r . -^5-P.. Discussion of Autecology of P. irregulare..and i t s Implication upon the Taxonomy.jsfJP. australe Among others, Chapman (191+2, 1961) and Stephenson (191+2) have stated that the proximity of a body cf sand to a rocky area w i l l a f f e c t the population of organisms growing on the rocks. According to Chapman (191+2), when rocks are sand~covered 5 very few Fucales are present and the vegetation consists of a Cladophora^Enteromorpha-Sphacelarla community. He considers the nature of the substratum (rock or sand) to be a factor that determines whether a plant w i l l be present or absent i n a l o c a l -i t y . Other authors (Cotton, 1912; Gibbs, 1939; Rees s 1935) have recorded sp e c i a l communities from sandy tide pools and sand-covered rocks. Cotton (1912) gives a detailed account of the algae occurring i n sand and sandy-mud areas at Clare Island, Ireland. These locations are characterized by a large quantity of movable sand or sandy mud i n which the plants are p a r t i a l l y or completely embedded. At Glacier Point, the algae found i n sandy and rocky areas are very d i f f e r e n t (Pig. 38, Table VIII )<, The sandy beaches at Glacier Point have spectacular seasonal changes i n which a l l of the sand may be removed during the winter, leaving only large boulders and exposed rocks. Irregu-l a r fluctuations occtir throughout the year. The changes des-cribed at Glacier Point also occur at Boomer Beach, La J o l l a , C a l i f o r n i a , and other l o c a l i t i e s where increased wave action and change of d i r e c t i o n of waves may remove most of the sand (Hedge-peth, 1957; Shepard, 191+8) „ The annual cycle results from the season of small waves (summer) at a time when sand i s deposited^, -56-and the stormy season (winter) at a time when the beaches are cut back (Shepard, 19Lj-8). Gail's (1918) experimental work on Fucus evanescens sug-gests that reduced l i g h t i n t e n s i t y may r e s t r i c t some plants to non-sandy areas. Mature plants of Fucus evanescens grown i n the f i e l d under t o t a l darkness began to decay a f t e r three weeks. Plants grown under one-eighth of the t o t a l l i g h t i n t e n s i t y were either dead or growth ceased after s i x weeks. As was mentioned e a r l i e r , the lower growing l i m i t s of Endocladia muricata, Fucus  evanescens, and Odonthalia floccosa are much higher i n sandy areas than i n corresponding rocky areas. This may r e f l e c t t h e i r l i m i t e d tolerance to sand coverage and, hence, reduced l i g h t i n t e n s i t y . At Glacier Point, the period of growth and repro-duction f o r P_. irregulare i s r e s t r i c t e d to the period of sand removal. The period when most plants are f e r t i l e (June to July) also coincides with the period of maximum sand deposition (Fig. 57). Thus, germlings of _P. irregulare must be able to with-stand prolonged sand coverage, because they are able to i n i t i a t e new macroscopic plants a f t e r the sand goes away (Tables I I , I I I , IV). The blades on the mature plants are ephemeral and die afte r prolonged submergence i n sand, but the holdfast i s much more resista n t and i s capable of i n i t i a t i n g new blades when the plants are uncovered (Fig. 2 i , 3a,b). The extreme resistance of the basal holdfast must p a r t i a l l y explain the a b i l i t y of JP. irreg u -lare to l i v e under such adverse conditions. Three perennial plants , P. irreg u l a r e , A h n f e l t i a concinna, and Gymnogongrus l i n e a r i s a r e apparently r e s t r i c t e d to sandy -57= areas at Glacier Point, and each species appears to have an incomplete alternation of generations. The l i f e h i s t o r y of P. irr e g u l a r e , as discussed e a r l i e r , i s of the "direct type," and i t i s assumed that reduction d i v i s i o n f a i l s to take place i n the unilocular sporangium. S i m i l a r l y , tetrasporophyte generations have not been reported f o r any species of Ahn f e l t i a or Gymnogongrus (G.M. Smith, I9I4I4.). Since a l l three species are obviously adapted to survive i n a sandy area, then an i n -complete alte r n a t i o n of generations insures successive gener-ations of g e n e t i c a l l y s i m i l a r plants.. Competition between other plants may r e s t r i c t P_. irregulare to sandy areas. In sheltered sandy areas (areas 1, 2, 6 b ) , a greater number and va r i e t y of plants can be found than i n ex-posed sandy areas. For example, on the sheltered eastern part of Glacier Point, many of the populations of P. irregulare are completely covered during the spring by Enteromorpha l i n z a , and very few plants of _P. irregulare are v i s i b l e except during the late winter (Pig. 21d). Several rocks with intact populations of P_. irregulare have been transplanted to rocky areas; i f the surrounding a l g a l populations were eliminated before transplant-ing, the transplanted plants grew just as well as the in s i t u ones. Such observations imply that P. irregulare can grow i n rocky areas i f competition from other plants i s eliminated. The period of maximum growth (February to A p r i l ) of P. irregulare i s associated with a corresponding increase i n water temperature and hours of bright sun (Fig. 30, 5 8 ) . Except f o r one rather high nitr a t e value recorded in March, -58 there was no conspicuous increase i n nutrients during t h i s period (Fig. 3 k , 35) o Surface water s a l i n i t i e s show the same trend (Fig, 32)<, This suggests that neither nutrients nor s a l i n i t i e s are l i m i t i n g f o r optimum growth of P_, irregulare , On the con-tr a r y , the period of decreased growth f o r the tide pool popu-lat i o n s (May to June) was associated with a corresponding increase in both surface water temperatures and l i g h t (Fig, 3 0 , 5 8 ) . Thus, the decreased rate of growth may have been p a r t i a l l y due to one of the following? (1) the water temperatures are too high for active growth; (2) the plants receive too much l i g h t ; (3) an int e r a c t i o n of high temperatures and high l i g h t i n t e n s i t i e s . The water temperatures i n tide pools are sometimes very high and possibly i n h i b i t i n g . The high surface water s a l i n i t i e s probably did not r e s t r i c t the growth of the plants, because they were only s l i g h t l y higher than those recorded e a r l i e r i n the year ( F i g D 3 2 ) . A minimum nit r a t e value of Z. 1 ug-at/1 was recorded in June, but t h i s value corresponded to a phosphate maximum of l k , 2 p.g-at/1 (Fig, 3 k , 35)o The phosphate maximum was probably not l i m i t i n g , but the n i t r a t e minimum may have contributed to a general de-crease i n growth. The growth of non-tide pool plants of P„ i r r e g -ulare began to decrease rapidly about A p r i l (Fig, k5s> k 6 , k 7 s 5 0 , 5 3 s 53)o This decrease i n growth i s more l i k e l y related to t i d a l exposure, because the number of daylight low tides increases rapid l y from March to June (Fig, 2 6 ) , This must be a c r i t i c a l period f o r the non-tide pool plants. Corresponding tide pool plants are not exposed to such extreme meteorological conditions. -59-Since such a desiccation d i f f e r e n t i a l exists between the tide pool and non-tide pool populations of P„ irreg u l a r e , i t is not surprising that most of the larger blades of the non-tide pool plants die off i n A p r i l to May when many daylight low tides occur. Thus, i n late spring the non-tide pool plants appear much smaller than the tide pool plants. The smallest non-tide pool plants were found on high rocks (above II feet) and on sloping substrates, where the most extreme periods of desic-cation occur (Fig. 29)o The above observations i n f e r that the macroscopic blades of P_. irregulare have a limited tolerance to desiccation during i n t e r t i d a l exposure, and that this must be one of the primary factors determining the upper d i s t r i -bution. I f the upper l i m i t s of P_. irregulare (approximately I4..6 feet) are compared with the series of c r i t i c a l levels shown in Table VI, i t i s evident that there is a close corre-l a t i o n to the I96I1 yearly and monthly averages of the HLLW and the LHLW at Glacier Point. According to Dawson (1958), P. australe i s distinguished from P_. irregulare by i t s smaller size and darker color: P_. australe i s 1.5 to 2.5 cm (up to LL cm) long, whereas P_. i r -regulare i s 15 to 25 cm (up to LLO cm) long; the former is blackish, whereas the l a t t e r i s l i g h t brown to olive-green i n color. However, the present studies of P. irregulare indicate that morphology of the blades i s extremely variable. Thus, ch a r a c t e r i s t i c s such as size and color are unsatisfactory c r i -t e r i a f o r distinguishing the two species, and do not support the separation into two species. In la t e spring, many of the -60-non-tide pool plants of P. irregulare at Glacier Point f a l l within the size range given by Dawson f o r P. australe , but the plants i n tide pools are much larger. Figure 56f shows the largest mature blades taken from a series of samples on a sloping substratum and a tide pool. There i s a great v a r i -ation i n size and color of the mature blades, and the l i m i t s of v a r i a b i l i t y of P. irregulare overlap the l i m i t s for P. australe. The type specimens of _P„ irregulare and P_„ australe are shown at the same scale i n Figure 56a,c,d. A l l specimens are rather old and i r r e g u l a r l y torn. Several younger blades of P. irregulare c o l l e c t e d from Cape Arago, Oregon, are shown i n Figure 56b; they are quite large and not conspicuously torn. Two other specimens of Phaeostrophion collected from Point Conception, C a l i f o r n i a are shown i n Figure 56e; they are much larger than the type specimens of P_. australe collected by Dawson at the same l o c a l i t y . This evidence supports the con-clusion that P_, australe i s nothing more than a g r o w t h s form of P_. irregulare. i - 6 1 V . E X P E R I M E N T A L E C O L O G Y L a b o r a t o r y e x p e r i m e n t s w e r e u n d e r t a k e n i n a n a t t e m p t t o d e t e r m i n e t h e m a j o r f a c t o r s i n f l u e n c i n g t h e g r o w t h a n d d i s t r i -b u t i o n o f T_. i r r e g u l a r e i n t h e f i e l d . T h e e x p e r i m e n t s w e r e c o n d u c t e d i n t h e f o l l o w i n g m a n n e r : ( 1 ) t h e g r o w t h o f g e r m l i n g s w a s d e t e r m i n e d u n d e r c o n s t a n t e n v i r o n m e n t a l c o n d i t i o n s ; ( 2 ) t h e p h o t o s y n t h e t i c r e s p o n s e o f t h e m a c r o s c o p i c p l a n t s w a s t e s t e d i n t h e W a r b u r g a p p a r a t u s u n d e r c o n s t a n t e n v i r o n m e n t a l c o n d i t i o n s ; ( 3 ) t h e t o l e r a n c e o f g e r m l i n g s a n d m a t u r e p l a n t s t o e x t r e m e s o f t e m p e r a t u r e , s a l i n i t y a n d d e s i c c a t i o n w a s d e t e r -m i n e d . A . G r o w t h o f G e r m l i n g s 1. M e t h o d I n a l l e x p e r i m e n t a l w o r k w i t h g e r m l i n g s , z o o s p o r e s w e r e a l l o w e d t o s e t t l e o n s l i d e s o r c o v e r s l i p s , a n d w e r e t h e n t r a n s f e r r e d t o d i f f e r e n t c o n t r o l l e d e n v i r o n m e n t s . T h e r e s p o n s e o f g e r m l i n g s t o v a r i o u s s a l i n i t i e s , t e m p e r a t u r e s , n u t r i e n t s ( n i t r a t e a n d p h o s p h a t e ) , l i g h t i n t e n s i t i e s , a n d l i g h t q u a l i t i e s w a s d e t e r m i n e d b y m e a s u r i n g e i t h e r t h e l e n g t h o f t h e g e r m l i n g s o r t h e p e r c e n t g e r m i n a t i o n o f t h e z o o s p o r e s . T h e l e n g t h m e a s -u r e m e n t r e p r e s e n t s t h e a v e r a g e o f 5 0 g e r m l i n g s e a c h , w h i l e t h e p e r c e n t g e r m i n a t i o n r e p r e s e n t s 5 0 0 p l a n t s . T h e d i f f e r e n t s a l i n i t i e s o f s e a w a t e r w e r e o b t a i n e d b y e i t h e r d i l u t i n g a s a m p l e o f s e a w a t e r (31.k- °/oo) c o l l e c t e d a t G l a c i e r P o i n t w i t h d i s t i l l e d w a t e r , o r b y a d d i n g d r i e d s a l t f r o m a s a m p l e o f e v a p o r a t e d s e a w a t e r . I n n u t r i e n t e x p e r i m e n t s various amounts of ni t r a t e ( 0 . 1 to 2 . 0 mM KNO-^/l) were added to the natural seawater sample (Table Ib,c). The additions of KNO^ correspond to the additions of 1 to 20 pg-at KO^/l, and the additions of K-JiPO^ correspond to the additions of 0.25 to 2 . 0 pg-at P0j^ /1 . The i n i t i a l concentration of n i t r a t e i n the seawater was 9 pg~at NO^/l; that of phosphate was l.kO pg-at POj^/1 . In the nutrient experiment, germlings were grown at l 5 ° 0 j i n s a l i n i t y experiments, at 10°C. Temperature experi-o ments were carried out at 5a 10, 15 and 20 C. A l l germlings were grown with 100 foot-candles of l i g h t provided with cool-white fluorescent tubes f o r l k hours per day. The d i f f e r e n t i n t e n s i t i e s of l i g h t used i n the l i g h t experiments were obtained by a l t e r i n g the number of banks of l i g h t s and the pos i t i o n of cultures in a 15°C constant environ-ment room. The i n t e n s i t i e s varied from 50 to 1000 foot-candles. The e f f e c t of d i f f e r e n t wave lengths of l i g h t was studied by growing germlings under a series of d i f f e r e n t colored cellophane f i l t e r s , Pigure 59 shows, f o r each f i l t e r , the absorption curve determined on a recording spectrophotometer. The maximum transmittance f o r each f i l t e r , and the l i g h t i n t e n s i t y reaching the surface of each p e t r i dish under the f i l t e r and the control are as follows: F i l t e r Maximum transmittance H Light i n t e n s i t y blue 3750-k500 and about 8000 51 foot-candles green about 3000, 5250 and 7750 52 n 3 red about 3500, 5750-8000 k2 tt w - 6 3 -o F i l t e r M a x i m u m t r a n s m i t t a n c e A L i g h t i n t e n s i t y p i n k a b o u t 3300-ILOOO a n d 6000 62 f o o t - c a n d l e s -8000 y e l l o w a b o u t 5500-8000 l l i l i " " c o n t r o l ( s e e F i g u r e 60) 317 w " T h e l i g h t i n t e n s i t y r e a c h i n g t h e s u r f a c e o f e a c h p e t r i d i s h w a s r e c o r d e d b y a P h o t o v o l t e l e c t r o n i c p h o t o m e t e r , w h i c h w a s n o t s e n s i t i v e t o a l l w a v e l e n g t h s o f l i g h t a v a i l a b l e u n d e r t h e f i l -o t e r s ( F i g . 6 1 ) . I t d o e s n o t r e c o r d w a v e l e n g t h s b e l o w 3000 A o a n d b e y o n d 6500 A . T h e e f f e c t o f d i f f e r e n c e s i n l i g h t i n t e n s i -t i e s w a s n o t e v a l u a t e d i n d e t a i l I n t h i s e x p e r i m e n t . 2. R e s u l t s a . S a l i n i t y - T w o s a l i n i t y e x p e r i m e n t s w e r e c o n d u c t e d . I n t h e f i r s t , t h e g e r m l i n g s w e r e e x p o s e d t o a w i d e r a n g e o f s a l i n i - • t i e s (0 t o 90 ° / o o ) a t i n t e r v a l s o f 5 ° / o o i n o r d e r t o d e t e r -m i n e t h e i r r a n g e o f t o l e r a n c e a n d t h e i r o p t i m a l s a l i n i t i e s f o r g r o w t h ( F i g , 62 , 6 3 ) . I n t h e s e c o n d e x p e r i m e n t , a m o r e d e t a i l e d a n a l y s i s o f t h e g e r m l i n g g r o w t h w a s m a d e b e t w e e n t h e s a l i n i t i e s o f 20 t o 50 ° / o o a t i n t e r v a l s o f 2 ° / o o ( F i g . 6LL, 6 5 ) . F r o m t h e p r e l i m i n a r y e x p e r i m e n t s , t w o f e a t u r e s a r e o b v i o u s : (1) t h e r a n g e o f t o l e r a n c e i s w i d e ^ , a n d (2) t h e t o l e r a n c e l i m i t s o f g e r m l i n g s f r o m u n i s p o r e s d i f f e r s f r o m t h a t o f p l u r i s p o r e s . T h e g e r m l i n g s f r o m p l u r i s p o r e s w i l l g r o w i n s a l i n i t i e s o f 5 t o 55 ° / o o , w h e r e a s t h o s e f r o m u n i s p o r e s w i l l g r o w i n 5 t o 70 ° / c o ( F i g . 62 , 6 3 ) . T h e o p t i m u m s a l i n i t y f o r b o t h g e r m l i n g s i s a b o u t 35 ° / o o , a n d t h e r e i s a d e c r e a s e i n t h e r a t e o f g r o w t h a b o v e a n d b e l o w t h i s v a l u e . T h e s e c o n d e x p e r i m e n t d e m o n s t r a t e s t h a t t h e o p t i m a l -6k -s a l i n i t i e s f o r g r o w t h a r e b e t w e e n 32 t o 36 ° / o o ( F i g „ 6k , 6 5 ) . T h e a p p e a r a n c e o f t h e c h l o r o p l a s t s i s a g o o d i n d i c a t o r o f " p h y s i o l o g i c a l s t a t e , " b e c a u s e t h e y a r e p a l e a n d p o o r l y d e v e l -o p e d w h e n t h e p l a n t s a r e m a i n t a i n e d i n s u b - o p t i m a l s a l i n i t i e s ( b e l o w 28 ° / o o ) . T h e c y t o p l a s m o f s u c h g e r m l i n g s h a s a m o r e g r a n u l a r a p p e a r a n c e , w h i c h i s d u e t o a n a b u n d a n c e o f f u c o s a n v e s i c l e s . G e r m l i n g s i n s a l i n i t i e s a b o v e 36 ° / o o a p p e a r p e r -f e c t l y n o r m a l a n d c a n n o t b e d i s t i n g u i s h e d m i c r o s c o p i c a l l y f r o m t h o s e i n t h e o p t i m a l s a l i n i t i e s (32 t o 36 ° / o o ) . G e r m l i n g s g r o w n i n v e r y d i l u t e s e a w a t e r (15 ° / o o a n d l e s s ) a r e a b n o r m a l a n d s o m e w h a t s p h e r i c a l . , S p o r a n g i a w e r e n o t p r o d u c e d o n a n y g e r m l i n g s g r o w n i n s a l i n i t i e s l e s s t h a n 28 ° / o o „ I t i s e v i d e n t f r o m t h e s e e x p e r i m e n t s t h a t g e r m l i n g s g r o w b e t t e r i n h i g h e r t h a n l o w e r s a l i n i t i e s . G e r m l i n g s i m m e r s e d i n f r e s h w a t e r f o r 2k h o u r s c a n g r o w i f t h e y a r e t r a n s f e r r e d t o h i g h e r s a l i n i t i e s ( 3 1 . k ° / o o ) , b u t i m m e r s i o n i n . f r e s h w a t e r f o r k8 h o u r s I s l e t h a l f o r m o s t g e r m l i n g s , b . T e m p e r a t u r e = F i g u r e s 66 a n d 67 s h o w t h e e f f e c t o f t e m p e r a t u r e u p o n t h e r a t e o f g r o w t h o f g e r m l i n g s f r o m u n i s p o r e s a n d p l u r i s p o r e s . T h e f a s t e s t r a t e o f g r o w t h o c c u r s a t 1 5 °C , b u t i t i s n o t m u c h g r e a t e r t h a n t h a t a t 1 0 ° C 0 T h e s l o w e s t r a t e o f g r o w t h i s f o u n d a t 5 ° G , a n d i n t e r m e d i a t e g r o w t h o c c u r s a t 2 0 °C . A l l g e r m l i n g s w e r e g r o w n I n s e a w a t e r f r o m G l a c i e r P o i n t ( s a l i n i t y 3 1 . k ° / o o ) . N o r e p r o d u c t i v e o r g a n s a r e p r o d u c e d o n g e r m l i n g s g r o w n a t 5 o r 2 0 ° G , b u t t h e y o c c u r c o n s i s t e n t l y a t 10 a n d l 5 ° G . - 6 5 -c . T e m p e r a t u r e a n d S a l i n i t y - P o u r s e r i e s o f g e r m l i n g c u l t u r e s w e r e p r e p a r e d u s i n g s i x s a l i n i t i e s (15, 2 0 , 25, 30, 35* 4-0 °/oo), One s e r i e s w a s s u b m i t t e d t o 5°0 , a s e c o n d t o 1 0 ° C , a t h i r d t o 1 5°C, a n d a f o u r t h t o 20°0„ T h e g r o w t h a n d p e r c e n t s u r v i v a l o f g e r m l i n g s f r o m b o t h u n i s p o r e s a n d p l u r i -s p o r e s w e r e r e c o r d e d ( F i g , 6 8 , 6 9 ) . A s w a s a n t i c i p a t e d f r o m t h e e a r l i e r s a l i n i t y e x p e r i m e n t s , t h e f a s t e s t r a t e o f g r o w t h o c c u r s i n t h e h i g h e r s a l i n i t i e s (30 t o LLO ° / o o ) , b u t t h e o p t i -mum s a l i n i t y v a r i e s w i t h t h e t y p e o f g e r m l i n g a n d t h e t e m p e r -a t u r e o f t h e c u l t u r e s o l u t i o n . T h e o p t i m u m s a l i n i t y f o r g e r m l i n g s f r o m p l u r i s p o r e s i s 35 ° / o o a t a l l t e m p e r a t u r e s t e s t e d , b u t t h e o p t i m u m s a l i n i t y f o r t h e g e r m l i n g s f r o m u n i s p o r e s v a r i e s w i t h t h e t e m p e r a t u r e ( P i g , 6 8 , 6 9 ) . A t 5 a n d 10°C t h e o p t i m u m s a l i n i t y f o r g e r m l i n g s f r o m u n i s p o r e s i s 35 ° / o o , b u t a t 15 a n d 20°C i t i s LLO ° / O O . A s i m i l a r t r e n d e x i s t s f o r g e r m l i n g s f r o m p l u r i s p o r e s a t 2 0 ° G , w h e r e g r o w t h a t LLO ° / O O i s n e a r l y a s g r e a t a s t h a t a t 35 ° / o o . T h e o p t i m u m s a l i n i t y a t 15 and_ 20°C f o r g e r m l i n g s f r o m u n i s p o r e s i s h i g h e r t h a n t h e a v e r a g e s a l i n i t y f o r s e a w a t e r (35 ° / o o ) , w h e r e a s t h e o p t i m u m s a l i n i t y a t 5 a n d 10°C i s c l o s e r t o t h e a v e r a g e s a l i n i t y f o r s e a w a t e r , ' ' T h e p e r c e n t g e r m i n a t i o n a l s o v a r i e s w i t h d i f f e r e n t s a l i n i -t i e s a n d t e m p e r a t u r e s ( P i g , 70, 71 a n d T a b l e X ) , I n g e n e r a l , t h e m a x i m u m g e r m i n a t i o n c o i n c i d e s w i t h t h e s a l i n i t i e s o f m a x i -m a l g r o w t h ( s e e P i g , 6 2 - 6 5 ) . T h e s u r v i v a l v a l u e s a r e o n l y s h o w n f o r t h e g e r m l i n g s f r o m u n i s p o r e s . T a b l e X s h o w s t h e — -P ^ T h e a v e r a g e s a l i n i t y o f s e a w a t e r I s c o n s i d e r e d t o b e 35 ° / o o ( S v e r d r u p , J o h n s o n a n d F l e m i n g , 19LL2). -66 -percent s u r v i v a l of unispores at s i x s a l i n i t i e s (15, 2 0 , 25, 3 0 , 35 , ° / o o ) and f o u r d i f f e r e n t temperatures (5, 1 0 , 15, 2 0 ° C ) . The highest s u r v i v a l values at the lower s a l i n i t i e s (15, 20 and 25 ° / o o ) are found at 5 and 10°C, and with an i n -crease i n temperature the s u r v i v a l decreases. Thus, at 20°C no germlings were a l i v e a f te r 50 days i n the 15 and 20 ° / o o s a l i n i t i e s . Pigure 71 shows the s u r v i v a l sequence at 20°C i n d i f f e r e n t s a l i n i t i e s . At 5 and 10°C the optimum s a l i n i t y f o r s u r v i v a l i s 35 ° / o o , but at 15 and 20°C i t i s kO ° / o o (Table X ) . Pigure 70 shows the percent s u r v i v a l f o r the s a l i n i t y range of 5 to 75 ° / o o at 10°C. At 10°C the highest s u r v i v a l rate occurs at 35 ° / o o , but i t decreases both above and below t h i s va lue . d. Ni t ra te - Pigure 72 shows the r e s u l t s of adding n i t r a t e to cultures of germlings from unispores . The rate of growth increases with an a d d i t i o n of n i t r a t e to a l e v e l of 0 ,75 KNO^ (7 .5 pg-at NO / l ) . The a d d i t i o n of 0.75 mM KNO^ was equiv-alent to a f i n a l n i t r a t e concentrat ion of 17.k ug -at/1 . A d d i -t ions beyond 0.75 mM KNO^ seem to have an i n h i b i t o r y e f f e c t , since the rate of growth of the germlings i s not as great as that at 0.75 mM KNO^ . The a d d i t i o n of n i t r a t e apparently influences pigment product ion , since the plants grown i n sea-water without addit ions of n i t r a t e had pale yellow c h l o r o p l a s t s , while those wi th addit ions of n i t r a t e had deep brown c h l o r o -p l a s t s . e. Phosphate - Pigure 73 shows the r e s u l t s of adding phos-phate to cul tures of germlings from unispores . The rate of growth increases with the a d d i t i o n of phosphate to a l e v e l of -67-0.1 raM K 2HP0^ (1.0 ,ng-at P0^/1) . The a d d i t i o n of 0.1 mM KpHPO^ i s equivalent to a f i n a l phosphate concentration of 2.LL ;ug-at P0^/1 . Addit ions of phosphate above t h i s l e v e l have an i n -h i b i t o r y e f f e c t s i m i l a r to that i n the n i t r a t e experiment. The rate of growth of germlings i n the phosphate experiment was never as great as that i n the n i t r a t e experiment (Pig . 7 2 ) . This i s probably due to the high n i t r a t e addit ions (2.0 mM KN0^/1 or 20 jug-at N O ^ / l ) used i n the experiment. Since t h i s value i s above the optimum n i t r a t e value , i t may be i n h i b i t o r y . f . Light I n t e n s i t y - Figure 7h summarizes the growth of germlings from unispores and plur ispores under d i f f e r e n t l i g h t i n t e n s i t i e s (af ter 25 days) . In genera l , the rate of growth of the two types of germlings was s i m i l a r except f o r minor v a r i -a t i o n s . An increase i n l i g h t i n t e n s i t y up to 100 foot -candles r e s u l t s i n a r a p i d increase i n growth. From 100 to 200 f o o t -candles the growth decreases, wi th germlings from unispores show-ing the most r a p i d decrease. At 200 to 5 0 0 foot -candles the growth f o r both types of germlings i s f a i r l y constant, but above 500 foot -candles growth decreases r a p i d l y . This suggests that l i g h t i n t e n s i t i e s of less than 100 foot -candles are suboptimal, whereas l i g h t i n t e n s i t i e s greater than 100 foot -candles are s a t u -r a t i n g . Prolonged exposure to l i g h t i n t e n s i t i e s greater than 700 foot -candles causes pronounced bleaching of the germlings. When the germlings were f i r s t placed under high l i g h t i n t e n s i t i e s f l they had deep brown chloroplasts^ but l a t e r t h e i r chloroplas ts became l i g h t yel low. Apparently , high l ight i n t e n s i t i e s are harm-f u l to the germlings. - 6 8 -g . Light Q u a l i t y - Table XI shows the growth of germlings from plur ispores under d i f f e r e n t wave lengths of l i g h t a f t e r 10 and k3 days. Maximum growth occurs under the blue and green f i l t e r s . The slow rate of growth of the c o n t r o l plants and those grown under the other f i l t e r s would probably not be due to i n h i b i t o r y l i g h t i n t e n s i t i e s , f o r the highest i n t e n s i t y was only 317 foot -candles (see F i g . 7k). The growth under the green f i l t e r was about 3.5 times that of the c o n t r o l , and plants grown under the blue f i l t e r show about the same growth as those under the green f i l t e r s . The high rate of growth of the germlings under the green and blue f i l t e r s i s probably due to the f i l t e r s c u t t i n g out the wave lengths of l i g h t i n the red p o r t i o n of the spectrum (6000 to 6800 2.), but a l lowing most of the i n f r a - r e d (7000 to 78OO £ ) to be t ransmit ted. This i s v e r i f i e d by the f o l l o w i n g f a c t s : ( l ) the germlings under the pink f i l t e r s have much less growth than those under the blue and green f i l t e r s , even though they have maximum transmittance i n the blue and green port ions of the spectrum; (2) the germlings under the red f i l t e r have a very slow growth and a maximum transmittance from about 6250 to 8000 (3) the energy spectrum of the cool-white f luorescent tubes have a maximum amount of energy i n the orange and red p o r t i o n of the spectrum ( F i g . 60). 3. Discuss ion of Growth of Germlings Several inves t iga tors (Kniep, 1907; Whitaker and Clancy, 1937; S a i t o , 1956a,b; Boalch, 1961; Sundene, 1962) have studied the e f f e c t of s a l i n i t y upon the growth and development of d i f -ferent brown algae. In most cases, growth occurs over a f a i r l y -69-wide range of s a l i n i t i e s , but optimal growth i s r e s t r i c t e d to a smaller range. For example, whitaker and Clancy (1937) found that i n a species of Fucus the eggs w i l l germinate i n s a l i n i t i e s ranging from 30 to 180 percent of seawater (sp. gr . 1 , 0 2 7 ) , but there is a marked optimum at s a l i n i t i e s ranging from 90 to 100 percent . A s i m i l a r s i t u a t i o n ex is ts i n P. i r r e g u l a r e , where the fas tes t rate of growth occurs between 32 to 36 ° / o o , although the s a l i n i t y tolerances are between 5 to 70 ° / o o f o r the germlings from unispores , and 5 to 55 ° / o o f o r the germlings from p l u r i s p o r e s , Saito (1956a,b) states that vegetative growth and f e r t i l i t y of Undaria p i n n a t i f i d a may be d i f f e r e n t i a l l y affected at various s a l i n i t i e s . Such is also the case with P_„ i r r e g u l a r e . As mentioned e a r l i e r , the s a l i n i t y optimum of germlings from unispores of P. i r r e g u l a r e var ies with the temperature, and the s a l i n i t y optimum i s greater at high than low temper-a tures . Germlings from plur ispores show the same t r e n d , but less d i s t i n c t l y , Boalch (1961), R i t c h i e (1957 s 5 9 ) , and Sundene (1962) record a s i m i l a r phenomenon i n t h e i r cul ture s t u d i e s . R i t c h i e was working with marine f u n g i , while Boalch and Sundene were working with Ectocarpus confervoides and A l a r i a esculenta , r e s p e c t i v e l y . The f i r s t two inves t igators state that the o p t i -mum s a l i n i t y f o r growth decreases with a decrease i n temper-ature , and that the s a l i n i t y optimum is below average seawater. The optimum s a l i n i t y f o r germling growth i n JP. i r r e g u l a r e does not r decrease with a decrease i n temperature, but the percent s u r v i v a l i n low s a l i n i t i e s (less than 25 ° / o o ) increases with a -70 . decrease i n temperature. Such t e m p e r a t u r e - s a l i n i t y i n t e r a c t i o n s may be very important; Boyle and Doty (191+9) suggest that the tolerance of stenohaline forms to reduced s a l i n i t i e s may be due to the coldness of the seawater. Several genera of brown algae are known to have a l i m i t e d temperature range f o r the onset of f e r t i l i t y : Laminaria  r e l i g i o s a (Ueda, 1929); Undaria p i n n a t i f i d a (Saito ,V, 1956a,b); Nereocystis luetkeana (Kemp and C o l e , l 9 6 l ) „ Under optimal s a l i n i t i e s , the germlings of P. i r r e g u l a r e w i l l to lera te temper-atures of 5 to 2 0 ° C , but become f e r t i l e only at 10 and 15°C. The fas tes t rate of growth occurs at 10 and 15°C. The temper-atures and s a l i n i t i e s recorded from the surf at G l a c i e r Point are lower than the optimal condit ions observed i n the l a b o r a -t o r y . However, P_. i r r e g u l a r e often occurs In t ide pools where the temperatures and s a l i n i t i e s are c loser to the optimal con-d i t i o n s determined i n the labora tory . The t ide pool tempera-tures f luc tuate much more than the s a l i n i t i e s . Boalch (1961), Harr ies (1932), and K y l i n (1916) have noted that supplements of n i t r a t e and phosphate accelerate growth and reproduction of d i f f e r e n t brown algae . Ectocarpus confervoides a t ta ins maximum growth with the a d d i t i o n of 0.5 mM of KWO^ and 0.1 mM of K 2HP0^ to natura l seawater (Boalch, 1961), The nitrate/phosphate r a t i o required f o r maximum growth of E c t o -carpus confervoides is 5/1. According to Boalch, this i s much lower than the t y p i c a l r a t i o s c i t e d f o r marine phytoplankton (16.3/1, Cooper, 1937; 1 8 / 1 , R e d f i e l d , 1931+). Boalch ( 1 9 6 1 ) d i d not record the i n i t i a l concentrat ion of n i t r a t e or phosphate -71-i n h i s natural seawater sample. The n i t r a t e experiments conducted upon P. i r r e g u l a r e demon-strate that germling development could be l i m i t e d by a ni t rogen d e f i c i e n c y below the optimum range (I7.I4.O ;ug-at N O ^ / D . This i s not an absolute l i m i t because growth occurs i n a l l of the concen-t r a t i o n s tes ted , as w e l l as i n the natural seawater sample (9.9 j u g - a t / l ) „ I f the seasonal d i s t r i b u t i o n of soluble n i t r a t e i n the surface water at G l a c i e r Point i s compared with the ...optimum n i -trate values determined, i t i s evident that i n most cases the n i -t rate i s i n excess of the optimum concentrat ion, A few values are below the optimum (Pig . 34- and 7 2 ) , but the only value which would d e f i n i t e l y i n h i b i t growth i s that recorded on June 12, 1961i. In contrast , the phosphate values recorded at G l a c i e r Point do not appear to be i n excess (Pig . 35 and 7 3 ) . A l l of the phos-phate values recorded between mid-December and late A p r i l are less than the optimal concentrations ( 2 . LLO ;ug-at P O ^ / 1 ) , but t h i s would not be a l i m i t i n g fac tor unless the phosphate concentration was much lower than l . i i O .,ug-at •. Some of the very low phosphate values encountered would be expected to i n h i b i t germling growth. Several extremely high phosphorus values are also found; these might be i n h i b i t o r y . B l inks (1955) suggests that most nutr ients (ni trogen, phosphorus) are i n great excess because of the decom-p o s i t i o n of i n t e r t i d a l populat ions . He postulates that t h i s may expla in the h i g h primary p r o d u c t i v i t y of coas ta l waters. On the contrary , the phosphate values at G l a c i e r Point are apparently r a r e l y optimal f o r germling growth of P . • i r r e g u l a r e . -72-Since the optimal n i t r a t e and phosphate concentrations f o r germling growth of P. irregulare are 1 7 . u g - a t NO^/1 and 2 . k 0 ug-at PO^/1, t h e i r N/P r a t i o i s 7.25/1 . The N/P r a t i o determined f o r P. irregulare i s higher than that found by Boalch (1961) f o r Ectocarpus confervoides ( 5 / 1 ) , but i t i s lower than the average N/P r a t i o of surface waters at- G l a c i e r Point (11 .1/1) . Although the n i t r a t e concentrations at Glacier Point are quite high, i t i s u n l i k e l y that they are i n h i b i t o r y , since the young plants grow r a p i d l y i n s i t u (Tables I I , I I I , IV). Such contra-dic t o r y r e s u l t s may be caused by the ni t r a t e and phosphate experiments being conducted with an i n h i b i t o r y concentration of phosphate and n i t r a t e . Thus, the n i t r a t e optimum may be higher with a reduced phosphate concentration, and vice versa. The germlings of JP. irregulare are light-saturated at very low l i g h t i n t e n s i t i e s (approximately 100 foot-candles). Boalch ( I 9 6 I ) Indicates that Ectocarpus confervoides is light-saturated at i n t e n s i t i e s as low as 125 foot-candles, but i n t e n s i t i e s of 1500 foot-candles are not i n h i b i t o r y . The optimum i n t e n s i t y f o r the production of p l u r i l o c u l a r sporangia i n Ectocarpus confer-voides i s 600 to 700 foot-candles. On the other hand, the gerra-l i n g s of P. irregulare are abnormal at l i g h t i n t e n s i t i e s of 700 foot-candles. The optimum l i g h t i n t e n s i t y f o r germlings of some of the Laminariales i s about the same as f o r P. ir r e g u -lare ; Laminaria angustata, 130 foot-candles (Hasegawa, 1962); Laminaria saccharina, 93 foot-candles (Harries, 1932). One might expect species of the genus Laminaria to be l i g h t - s a t u -rated at low l i g h t i n t e n s i t i e s because they are pri m a r i l y i - 7 3 -s u b t i d a l . Since the germlings of P. i r r e g u l a r e grow most r a p i d l y under low l i g h t i n t e n s i t i e s , they are obviously adap-ted to the low l i g h t i n t e n s i t i e s that occur during the winter ( P i g . 58). It i s not s u r p r i s i n g , therefore , that t h e i r maxi-mum growth occurs at t h i s time. The experiment on l i g h t q u a l i t y suggests that there i s a r e d - i n f r a - r e d i n t e r a c t i o n which i s important f o r germling growth i n JP. i r r e g u l a r e . S i m i l a r phenomena are wel l known i n f lowering p l a n t s , and Van Der Veen and Mei jer ( 1 9 5 9 ) give a d e t a i l e d account of r e d - i n f r a - r e d r e a c t i o n s . Lettuce seed germination i s promoted o by red l i g h t of 6000 to 6800 A , but i t i s i n h i b i t e d by f a r - r e d or near f a r - r e d l i g h t of 7000 to 7800 A* . On the contrary , seed germination i n cucumber and tomato is retarded by red l i g h t , but promoted by f a r - r e d l i g h t . The antagonist ic e f f e c t s of one s p e c t r a l zone can be reversed i f i r r a d i a t i o n by the other spec-t r a l zone occurs quickly a f t e r the other . The growth response of germlings of P. i r regulare i n the l i g h t q u a l i t y experiment appears to be due to an I n h i b i t i o n of red l i g h t , and a promotion of f a r - r e d l i g h t . - 7 k B. Photosynthesis and Respirat ion of Macroscopic Plants 1. Methods The mater ia l used f o r the photosynthesis and r e s p i r a t i o n experiments was c o l l e c t e d at G l a c i e r P o i n t , and then t r a n s -ported to the laboratory i n p l a s t i c bags stored i n an ice chest . Transportat ion took approximately four hours . The mater ia l was then sorted and prepared for the experiments. In a l l e x p e r i -ments a standard size (diameter 11 mm) disc was cut from the mater ia l with a cork borer . Discs were cut from both the blades and h o l d f a s t s . Experiments were conducted 2k hours a f t e r pre -paring the discs i n order to avoid wound r e s p i r a t i o n . A f t e r o being cut , the discs were retained at 10 C under 317 f o o t - c a n d l e s . The rates of gaseous exchange f o r the samples were recorded i n the Warburg apparatus at d i f f e r e n t l i g h t i n t e n s i t i e s , temper-atures , s a l i n i t i e s , and nutr ients (E0^ and POj^). In l i g h t and temperature experiments, measurements were completed w i t h i n three days of c o l l e c t i o n . For the s a l i n i t y and'nutrient experl- - . ments, plants were Immersed i n the d i f f e r e n t solut ions f o r f i v e days, and then the ra te of gaseous exchange was recorded w i t h i n t\<Jo days. A s a l i n i t y range of 20 to kO ° / o o was used. The addit ions of n i t r a t e and phosphate were i d e n t i c a l to those used f o r the germling experiments (see Table I b , c ) . In a l l of the photosynthetic experiments, two discs were, used per f l a s k (average volume . l8.5 mm). The discs were damp-d r i e d and then immersed in 5 ml of buffered a r t i f i c i a l seawater (Table X I I ) , A two percent atmosphere of carbon dioxide was - 7 5 -provided f o r the f l a s k s by adding 0,7 ml of a diethanolamine s o l u t i o n (Table XIII) to the f l a s k s (O.LL ml to the center w e l l and 0 ,3 ml to the side arm). A f l u t e d f i l t e r paper was then inser ted into the center w e l l of the f l a s k to increase the s u r -face exchange of CO2 . It was found that l i t t l e or no photosyn-thesis occurred i f a 00^ atmosphere was not provided. In the r e s p i r a t i o n experiments, 12 to 15 d iscs were used per f l a s k . Each f l a s k was f i l l e d with 5 ml of seawater, and 0,3 ml 20 percent KOH s o l u t i o n was added to the center w e l l with a f i l t e r paper to absorb the CO^ . The plant t i ssue was not used more than once i n any experiment. The f l a s k s were e q u i l i b r a t e d 30 minutes p r i o r to each run i n order to keep the temperatures of the f lasks and water bath i d e n t i c a l . Each run was made f o r 60 to 90 minutes, and readings were taken at 10-minute i n t e r v a l s . Seven r e p l i c a t e s were used f o r each experiment. A l i g h t source on the Warburg apparatus was provided by a series of incandescent l i g h t bulbs attached to an adjustable holder . With such an apparatus, the l i g h t i n t e n s i t y reaching the bottom of the f l a s k could be var ied by a l t e r i n g the type of bulb (wattage), the number of b u l b s , and t h e i r height above the water bath. A ser ies of d i f f e r e n t l i g h t i n t e n s i t i e s was ob-tained, , varying from approximately 150 to 1300 f o o t - c a n d l e s . At 500 foot -candles and greater i n t e n s i t i e s , the water temper-ature of the bath was c a r e f u l l y c o n t r o l l e d to prevent warming. For a l l experiments the water temperature was cooled by running tap water through c o i l e d aluminum tubing that was immersed i n -76-the bath; th is method was quite e f f e c t i v e i n cool ing the water to approximately 11°C. By running the water r a p i d l y through the tubing , and by adjust ing the thermostat of the bath, any o desired temperature from 11 C or higher could be maintained o e a s i l y . For temperatures of less than 11 C, a portable r e -f r i g e r a t i o n temperature c o n t r o l u n i t was used i n a d d i t i o n to the aluminum t u b i n g . The data obtained from the photosynthesis and r e s p i r a t i o n experiments are expressed as u l C^/g dry wt/10 min, 2 . Results a. Light In tens i ty - The rate of apparent photosynthesis f o r the blades and holdfas ts at 11,5°C under d i f f e r e n t l i g h t i n t e n s i t i e s i s shown i n Figure 75 . ^ The rate of apparent photo-synthesis f o r both the blades and holdfas ts increases with an increase i n l i g h t i n t e n s i t y up to approximately 680 f o o t - c a n d l e s ; above 680 foot -candles the rate of photosynthesis d e c l i n e s . This indicates that l i g h t i n t e n s i t i e s of less than 680 f o o t -candles are l i m i t i n g f o r photosynthesis of both the blades and h o l d f a s t s , whereas those above 680 foot -candles are s a t u r a t i n g . Although both blades and holdfas ts have a s i m i l a r sa turat ion p o i n t , the photosynthetic rate of the blades f a l l s o f f more r a p i d l y than that of the holdfas ts at higher l i g h t i n t e n s i t i e s ( 8 0 0 to 9 2 0 f o o t - c a n d l e s ) . In a l l cases, the rate of photo-synthesis was much lower f o r the holdfas ts than the blades . r °Apparent or net photosynthesis refers to the excess of photosynthesis over r e s p i r a t i o n , and i t i s not equivalent to t o t a l photosynthesis . -77-There i s a d i s t i n c t d i f ference between the ra te of photosynthesis of o l d holdfas ts and young ones. The young holdfasts are ob-v i o u s l y i n a more active state of growth when the blade i n i t i a l s are being i n i t i a t e d . b . Temperature - The rate of apparent photosynthesis f o r the blades and holdfas ts at d i f f e r e n t temperatures and 588 f o o t -candles i s shown i n Figure 76. The rate of apparent photosyn-thesis f o r both the blades and holdfas ts increases, with an increase i n temperature up to 1 3 . 5 °C , above 13.5°C i t decreases. The rate of apparent photosynthesis at a l l temperatures tested i s much greater f o r the blades than f o r the h o l d f a s t s . The h o l d -f a s t s maintain a f a i r l y uniform rate of photosynthesis between 11.5 to 17.5°C> but the rate of apparent photosynthesis for the . 0 blades f a l l s more r a p i d l y above and below 13.5 c « The rate of r e s p i r a t i o n f o r the blades and holdfasts increases with an increase i n temperature ( F i g . 77)» but the maximum rate of r e s -p i r a t i o n recorded f o r both: i s very low: 6 p l 0 ^ /g dry wt/10 min f o r the h o l d f a s t s , and 28 .5 P-l C^/g dry wt/10 min f o r the blades . As a resul t of the low r e s p i r a t i o n rates and the high photosyn-thesis ra tes , the p h o t o s y n t h e s i s / r e s p i r a t i o n r a t i o s are very l a r g e . Table XIV l i s t s the P/R r a t i o s f o r both blades and h o l d -f a s t s at seven d i f f e r e n t temperatures. The largest r a t i o s occur at 13 .5°C. c . S a l i n i t y - The rate of r e s p i r a t i o n and apparent photo-synthesis f o r the blades i n d i f f e r e n t s a l i n i t i e s at 11.5°C and 588 foot -candles i s shown i n Figures 78 and 79. Neither the rate of r e s p i r a t i o n nor the apparent photosynthesis i s -78-conspicuously d i f f e r e n t at any of the s a l i n i t i e s tested (20 to kO ° / o o ) . The minimum rate of r e s p i r a t i o n was recorded a t 30 ° / o o , but the value i s not conspicuously d i f f e r e n t than those at other s a l i n i t i e s . The maximum rate of photosynthesis was recorded at 32 ° / o o and kO ° / o o , but the values are not con-spicuously d i f f e r e n t from those at other s a l i n i t i e s . In the s a l i n i t y experiment, the rate of photosynthesis at1 32 ° / o o and 11.5°C i s much less than that at 31. k ° / o o and 11.5°C i n the l i g h t experiment. The lower rate of r e s p i r a t i o n f o r plants i n the s a l i n i t y experiment is probably due to the older age of the mater ia l (the long period of immersion i n the s a l i n i t i e s p r i o r to measurement of photosynthesis and r e s p i r a t i o n ) . d . Nutr ients - The rate of apparent photosynthesis for the blades i n d i f f e r e n t phosphate concentrations at l l . f ? ° C i s shown i n Pigure 80. When the i n i t i a l concentrations of n i t r a t e and phosphate i n the natura l seawater sample were h i g h ( 5 l . O ug-at N O ^ / l , and 2.15 P-g-at P0^/1), the rate of apparent photosyn-thesis increased with the a d d i t i o n of phosphate up to 1 ug-at P0|^/1 , but thereaf ter i t decreased. Pigure 8 l shows the rate of apparent photosynthesis f o r the blades i n d i f f e r e n t n i t r a t e concentrations at 1 1 .5°C. Two samples of water were used. In the f i r s t , the n i t r a t e and phosphate concentrations of the natural seawater sample were 31 .0 ug-at NO-j/l and k . 15 ug-at P0j^/1 , while i n the second, the n i t r a t e and phosphate concen-t r a t i o n s were lower (7 .0 ug-at N O ^ / l and 2.03 ug-at PO^/1). In the f i r s t n i t r a t e experiment, the rate of apparent photo-synthesis did not increase conspicuously with the a d d i t i o n of -79-n i t r a t e . In the second, the rate of apparent photosynthesis showed a rapid increase with the a d d i t i o n of n i t r a t e up to about 7.5 ug-at/1 . The rate of photosynthesis was not measured over a wide range of addit ions i n the second n i t r a t e experiment. The rate of apparent photosynthesis i n the second experiment i s much greater than that of the f i r s t , suggesting that the n i t r a t e concentrations i n the second are more s u i t a b l e . 3 . Discuss ion of Photosynthesis and R e s p i r a t i o n in'  Macroscopic Plants The sa tura t ion i n t e n s i t y f o r germling growth and photosyn-thesis of the macroscopic plants of JR. i r r e g u l a r e are very d i f -f e r e n t . The apparent photosynthesis of the macroscopic plants i s l i g h t - s a t u r a t e d at about 700 f o o t - c a n d l e s , whereas germlings are injured at the same i n t e n s i t y and saturated at 100 f o o t -candles , The optimal l i g h t i n t e n s i t y f o r i n t e r t i d a l algae i s higher than that f o r s u b t i d a l algae. For example, the sa tura t ion i n t e n s i t y f o r Fucus serratus ( i n t e r t i d a l ) i s 2325 foot -candles at 25°0 (Rabinowitch, 1956)* while that f o r Macrocystis p y r i f e r a (subtidal) i s 1000 foot -candles at 25°C (Clendenning and Sargent, 1957). According to Chapman (1962) , only parts of the s u b t i d a l Egregia l a e v i g a t a are l i g h t - s a t u r a t e d at ILLOO foot -candles at 20°C. Stocker and Holdheide (1938) describe a d i f f e r e n t i a l l i g h t optimum for several other i n t e r t i d a l and s u b t i d a l a lgae . At 11.5°C the blades and holdfas ts of P. i r r e g u l a r e are l i g h t - s a t u -rated at much lower l i g h t i n t e n s i t i e s than those of many deep-growing algae, such as Egregia l a e v i g a t a and Macrocystis p y r i f e r a . - 8 0 -The low saturat ion i n t e n s i t y of the macroscopic plants of P_. i r regulare may be an advantage i n a sandy area. Although o t h e i r sa turat ion i n t e n s i t y i s r e l a t i v e l y low at 11 C , i t i s possible that i t may be somewhat d i f f e r e n t at another temper-ature . Sai to (1956c) states that the optimum l i g h t i n t e n s i t y f o r macroscopic plants of Undaria p i n n a t i f i d a is cor re la ted with the water temperature; thus, at 10 and 15°C the optimum l i g h t i n t e n s i t y i s i 8 6 0 f o o t - c a n d l e s , but at 5°C i t i s 2790 to 3255 f o o t - c a n d l e s . This i s almost a two-fold increase at 5°C. The blades of P. i r r e g u l a r e must be the main photosynthetic organs of the p l a n t , because t h e i r rate of photosynthesis i s much greater than that of the h o l d f a s t s . Both organs are l i g h t -saturated at about the same i n t e n s i t y . However, o lder holdfas ts show a lower rate of apparent photosynthesis under optimal l i g h t i n t e n s i t y (680 foot -candles) than the younger, a c t i v e l y growing h o l d f a s t s . Chapman (1962) notes a higher rate of photosynthesis f o r the young " leaves" of Egregia laeviga ta than the old " l e a v e s . " No s i m i l a r comparison was made f o r blades of P_. i r r e g u l a r e at d i f f e r e n t ages. The germlings of P. i r r e g u l a r e were grown at 5 , 10, 15 and 20°C, and the f a s t e s t rate of growth occurred at l 5 ° C . This i s very close to the temperature at which the maxi-mum rate of apparent photosynthesis of the macroscopic plants occurs (13.5 C ) . Although the optimum temperature f o r blades o and holdfas ts i s approximately 13.5 C, a high photosynthetic rate also occurs over a wide range o f temperatures. This im-p l i e s that the plants are w e l l adapted to a t ide pool e n v i r o n -ment where pronounced temperature changes occur. The holdfas ts - 8 1 -are probably less s e n s i t i v e to a wide range of temperatures and l i g h t i n t e n s i t i e s than the blades , f o r the holdfasts maintain a more uniform rate of photosynthesis over a greater range of temperatures and l i g h t i n t e n s i t i e s than the blades . The r e s p i r a t i o n rates of blades and holdfas ts increases with an increase of temperature but , even so, the maximum values r e -corded are very low: 6 p i Og/g dry wt/10 min f o r the h o l d f a s t , and 28 .5 p i 0 2 g dry wt/10 min f o r the blades. The P/R r a t i o s of P. i r r e g u l a r e are very high because of the low r e s p i r a t i o n r a t e s . Clendenning and Sargent (1957) record comparable P/R r a t i o s f o r Macrocystis p y r i f e r a (range 13 to 34-/1), but those of P. i r r e g u l a r e are s t i l l higher (Table XIV) . The youngest blades of M. p y r i f e r a show the highest r a t i o s , while the older blades have lower values ( 6 . 5 to 18 .7/1) . The s t ipes have the lowest P/R value (k . 1/1) . The very high P/R r a t i o s recorded f o r the blades of P_. i r r e g u l a r e may r e f l e c t a s i m i l a r phenomenon, f o r the discs were always taken very close to the i n t e r c a l a r y meristem, and the c e l l s were probably a c t i v e l y d i v i d i n g and growing. How-ever, t h i s cannot completely expla in the low rate of r e s p i r a t i o n of the p l a n t , because the old holdfas t materials were not a c t i v e l y growing (not i n i t i a t i n g blades) and r e s p i r a t i o n was even lower. The extremely low r e s p i r a t i o n rate of the holdfas t may be p a r -t i a l l y due to the smaller proport ion of l i v i n g t issue per gram dry weight of the holdfas t than of the blade . This may have influenced the photosynthetic measurements of the holdfast as w e l l , but i n any event the r e s p i r a t i o n rates are extremely low. - 8 2 -The low r e s p i r a t i o n rate of the holdfas ts and blades of P_. i r r e g u l a r e may be of some adaptive value to a plant i n a sandy h a b i t a t , since such high P/R values would insure a photo-synthetic surplus during c r i t i c a l per iods . Since the perennial holdfas ts are of ten buried f o r prolonged per iods , t h e i r low r e s p i r a t i o n rate is obviously s u f f i c i e n t to sustain them u n t i l the sand is removed. It i s possible that the r e s p i r a t o r y rate of _P. i r regulare may be even lower than those recorded e x p e r i -mentally i n the Warburg apparatus a f t e r prolonged periods of sand coverage, since Kniep (1911+) states that i n a species of Fucus the r e s p i r a t i o n rate s t e a d i l y decreases a f t e r prolonged periods of darkness. A f t e r one month i t s r e s p i r a t o r y rate i s less than h a l f the o r i g i n a l ra te , and a f t e r f i v e months the r e s p i r a t o r y rate i s less than one quarter . He also suggests that low r e s p i r -a t ion rates could account f o r s u r v i v a l of algae i n prolonged periods of darkness, such as during the winter i n the a r c t i c . Several workers, i n c l u d i n g Burrows (1958) and Doty (1957), i n f e r that the germling stages of marine plants are more s e n s i -t i v e to extreme condit ions than the mature stages. The s a l i n i t y experiments conducted upon the germlings and macroscopic plants of _P. i r r e g u l a r e confirm this suggestion. Thus, the optimal s a l i n i t i e s f o r germling growth are 32 to 36 ° / o o , while nei ther r e s p i r a t i o n nor apparent photosynthesis of the blades i s con-spicuously d i f f e r e n t at s a l i n i t i e s ranging from 20 ,to 1+0 ° / o o . In the phosphate experiment, the maximum rate of photosyn-thesis was recorded at 3.15 pg-at F0^/1 . Addit ions of phosphate above 3.15 pg-at POiVl are probably i n excess f o r the macroscopic - 8 3 -plants at 11.5 C and with a sa turat ing amount of n i t r a t e C51.0 ug-at N O ^ / l ) . The maximum rate of growth f o r the germlings occurs at a lower phosphate concentration than 3.15 pg-at ?0^/l (between 2.1+ to 2 .65 pg-at PO^/1). However, the germlings were grown at 15°C and with a lower n i t r a t e concentration (29.9 ug-at N O ^ / l ) . The r e s u l t s of the two n i t r a t e experiments conducted with the Warburg apparatus suggest that n i t r a t e concentrations above 31 ug-at N O ^ / l are probably i n excess f o r the macroscopic plants of P. i r r e g u l a r e at 11 ,5°C, but n i t r a t e concentrations of l l | . 5 pg-at N O ^ / l at 11.5°C are not i n excess. The f a c t that the photosynthetic rates i n the second n i t r a t e experiment were much greater than those of the f i r s t , a lso substantiates the previous suggestion. The maximum rate of growth f o r germlings i n the n i t r a t e experiment was recorded at 17.1+ pg-at NO-j/l . The germlings were grown at 15°C with a phosphate concentration of 3.1+0 pg-at P0^/1 , whereas the rate of photosynthesis of the 0 blades was recorded at 11.5 C with phosphate concentrations of 1+.15 pg-at P0^ ( f i r s t n i t r a t e experiment) and 2 .03 pg-at POj^  (second n i t r a t e experiment). R i l e y e_t a l (191+9) indicate that the nutr ient requirements of marine photoplankton vary at d i f f e r e n t temperatures. Thus, at h i g h temperatures only a very low phosphate concentration l i m i t s growth, whereas at lower temperatures a higher phosphate concentration l i m i t s growth. The optimal nutr ient requirements of P. i r r e g u l a r e may also be re la ted to temperature, and t h i s may expla in the dif ferences recorded between photosynthesis and cul ture experiments. The fact that n i t r a t e and phosphate - 8 k -experiments were conducted with very h i g h concentrations of phosphate and n i t r a t e , r e s p e c t i v e l y may have inf luenced the optimum values recorded. For example, i n the n i t r a t e e x p e r i -ment the average length of 50 germlings a f t e r 20 days i n 29.9 ug-at N O ^ / l and 3.1). ug-at PO^/1 was about 30 p. ( F i g . 72). In the phosphate experiment with the same n i t r a t e concentrat ions , the average growth v a r i e d from about 150 to 65 P- , depending upon the phosphate concentration ( F i g . 73). Thus, there i s probably a range of nutr ient concentrations i n nature that are optimal f o r growth, rather than a s ingle absolute concentrat ion . As discussed e a r l i e r , i t i s u n l i k e l y that the n i t r a t e con-centrations i n nature are " i n h i b i t o r y " to the growth of P. i r r e g u -lare , f o r the germlings and macroscopic plants grow r a p i d l y i n  s i t u . It i s quite possible that the n i t r a t e optimum might be higher i n nature than the optimum recorded i n the labora tory , since lower phosphate values were u s u a l l y found. In any event, the n i t r a t e was probably i n excess, whereas the phosphate was not . -85-Co Tolerance Experiments on Germlings and Macroscopic Plants 1. Methods a. Temperature Tolerance - Experiments were conducted on blades to determine t h e i r tolerance to extreme temperatures. Samples were immersed i n test tubes and exposed to d i f f e r e n t temperatures i n the Warburg bath. Ten r e p l i c a t e s were used i n each experiment. At the beginning of each experiment, the sea-water temperature of the tes t tubes was e q u i l i b r a t e d with that of the bath; t h e r e a f t e r , the temperature's- of both could be i n -creased without a conspicuous l a g . The experiments were i n i t i -o ated at 11 C . Le thal temperatures were determined by r a i s i n g the temperature of the bath at a rate of one centigrade degree every f i v e minutes. The test tubes containing the materials were removed at various temperature i n t e r v a l s and returned to o 11 C. Portions of the blades were t ransferred to a 1.0 percent seawater s o l u t i o n of 2, k, 6 - t r imethyltetrazol iumch. lor ide (TTZ). A f t e r 2k hours they were examined m i c r o s c o p i c a l l y to determine v i a b i l i t y . TTZ i s a v i a b i l i t y i n d i c a t o r which changes from a c l e a r to a red color upon acceptance of an e lec t ron from a r e -s p i r i n g organism (P .E . Smith, 1951). I f the plants were a l i v e , the red c o l o r (formazan pigment) could be seen w i t h i n the c e l l s . The l e t h a l temperatures of several other associated plants at G l a c i e r Point were a lso determined. The temperature tolerance of the plur ispores of _P. i r r e g u l a r e were determined as w e l l . The procedure followed was the same as that used f o r the other plants with the f o l l o w i n g m o d i f i c a t i o n s : (1) a dense inoculum -86-of spores was used i n each tes t tube, and (2) TTZ was not used to test f o r v i a b i l i t y . Instead, the p lur ispores were deposited i n a p e t r i dish, a f t e r exposure to a s p e c i f i c temperature, and the percent germination was recorded a f t e r two weeks, In a second set of experiments with the macroscopic plants of P„ i r r e g u l a r e , the e f f e c t of a sudden exposure to very high temperatures was inves t iga ted . Blades and holdfasts were q u i c k l y t ransferred from 10°C to 22, 28, 3k, 38, 39 and kO°C. Samples were removed at f ive-minute i n t e r v a l s and returned to 10°C. The plants were then tested i n TTZ and t h e i r v i a b i l i t y was determined a f t e r 2k hours . b . S a l i n i t y tolerance - The tolerance of the macroscopic plants of P. i r r e g u l a r e , and several associated plants from G l a c i e r Point , to sudden extremes of s a l i n i t i e s was invest igated at 15°C ( in a constant environment room). Samples were immersed i n various s a l i n i t i e s ( in p e t r i dishes) f o r 2k hours and then tested f o r v i a b i l i t y i n the standard way with TTZ. However, some d i f f i c u l t y occurred because not a l l c e l l s responded equal ly to a given s a l i n i t y . In such instances , the f i r s t i n d i c a t i o n of any abnormality i n the protoplasm was used as an i n d i c a t o r of death. In a second experiment, the s a l i n i t y tolerance of the macro-scopic plants of P. i r r e g u l a r e was re la ted to the time of immer-sion i n d i f f e r e n t s a l i n i t i e s . Samples of the materials were taken out on d i f f e r e n t days. If they showed some i n d i c a t i o n of i n j u r y upon microscopic examination, they were then tested with TTZ. The f i r s t symptoms of i n j u r y i n the c e l l s are u s u a l l y associated with the c h l o r o p l a s t s , f o r they become deformed. -87-c. Des icca t ion Tolerance - Three types of d e s i c c a t i o n ex-periments were conducted upon P_. i r r e g u l a r e : (1) study of rate of water loss of macroscopic plants both i n the f i e l d and under laboratory c o n d i t i o n s ; (2) study of the v i a b i l i t y of macro-scopic plants i n r e l a t i o n to the amount of water l o s s ; (3) study of the l e t h a l d e s i c c a t i o n time f o r young germlings (one month o l d ) . A TTZ test was used to indicate the v i a b i l i t y of a l l m a t e r i a l s . The rate of water loss i n the f i e l d and laboratory was deter-mined by weighing the plants i n i t i a l l y a f t e r being damp-dried, and at d i f f e r e n t time i n t e r v a l s t h e r e a f t e r . The loss of water was expressed as the percent of the i n i t i a l damp-dried weight. Resistance to d e s i c c a t i o n was determined i n the laboratory by exposing damp-dried plants to d e s i c c a t i o n over a bed of calcium c h l o r i d e . The i n i t i a l weight of the plants was determined by weighing the f i l l e d v i a l s . At d i f f e r e n t i n t e r v a l s the plants were removed and t h e i r loss of water c a l c u l a t e d by weighing the v i a l s . Subsequently, the plants were immersed again i n seawater and l a t e r tested f o r t h e i r v i a b i l i t y with TTZ. A l l experiments were performed at room temperature (approximately 21 °C) . The procedure f o r the d e s i c c a t i o n experiments was s i m i l a r to that employed by Broekhuysen (191L0), working wi th marine gastropods. The time f o r l e t h a l d e s i c c a t i o n of the germlings of P_. i r regulare was determined by exposing s l i d e s of germlings to a i r f o r d i f f e r e n t p e r i o d s . The s l i d e s were then immersed again i n seawater and l a t e r tested with the v i a b i l i t y i n d i c a t o r . 8 8 -2. Results a. Temperature Tolerance - The l e t h a l temperature f o r the blades and holdfas ts of P. i r r e g u l a r e l i e s between 39 to kO°C (Pig . 8 2 ) . No dif ference could be found i n any mature plants of P. i r r e g u l a r e from d i f f e r e n t l e v e l s i n the i n t e r t i d a l zone. The l e t h a l temperatures of several other associated plants are shown i n Figure 82. The plants are a l l found i n areas 6 a , b or 7 at G l a c i e r P o i n t . In general , the plants which grow highest (see F i g . 2k) can withstand the greatest extremes of temperature. An exception i s Gymnogongrus l i n e a r i s . Of 25 d i f f e r e n t species of plants examined, only Bangia fuscopurpurea, Fucus evanescens, and Gymnogongrus l i n e a r i s have higher l e t h a l temperatures than that of P. i r r e g u l a r e . The l e t h a l temperature f o r p l u r i s p o r e s i s approximately 35°C<, because the percent germination i s less than one percent a f t e r o o an exposure of 35 C ( F i g , 8 3 ) . Below 28 C there i s no i n h i b i t i o n of zoospore germination, but above 28°C the percent germination decl ines r a p i d l y . There is no conspicuous difference i n the rate of growth f o r any of the s u r v i v i n g germlings. The l e t h a l temperature of the blades of P_. i r r e g u l a r e var ies . with s a l i n i t y ( F i g o 8J4). For example, at 38°G a l l blades remained a l i v e i n s a l i n i t i e s of 30 to 50 ° / o o , whereas at 38.5°C only those plants i n the optimal s a l i n i t i e s (30 to kO ° / o o ) were not Injured. At 39°C a l l blades were dead, regardless of the s a l i n -i t y . Figure 85 shows the v i a b i l i t y of blades a f t e r t ransfer from 10°C to higher temperatures. The response of the holdfas ts and blades of P. i r r e g u l a r e was i d e n t i c a l . No plants died af ter - 8 9 -f i v e minutes of exposure to 22 to 38 C . Approximately LLO percent died at 39°C a f t e r f i v e minutes, and a l l were dead at LLO°C . A l l o plants died a f t e r twenty minutes of exposure to 3k- C or h igher . b . S a l i n i t y Tolerance - A f t e r 2l± hours, the usual range of s a l i n i t y tolerance f o r the blades of P. i r r e g u l a r e at 1$°C i s 0 to 95 ° / o o (F ig , 86-87). In many instances , holdfas ts and young blades can tolerate s a l i n i t i e s of 0 to 120 ° / o o f o r several days and s t i l l give a p o s i t i v e TTZ t e s t . Relat ive d i f ferences can also occur i n the tolerance of blades to f resh water, and some blades are injured af te r 2l± hours i n f resh water. A f t e r 5 to 10 days of immersion i n f resh water, a l l plants die ( F i g . 86). The tolerance to h igh s a l i n i t i e s decreases with an increase i n time, and i n the experiment a f t e r 25 days the maximum s a l i n i t y i n which any plants were l i v i n g was 79 ° / o o ( F i g . 86). At the same t ime, the minimum s a l i n i t y tolerance was 6 ° / o o . The s a l i n i t y tolerances of several plants at G l a c i e r Point are shown i n Figure 87. The plants are l i s t e d according t o ; t h e i r maximum tolerance , and i t i s evident that the plants from the highest l e v e l of the i n t e r t i d a l zone can withstand the most extreme s a l i n i t i e s (see F i g . 2li)» Several plants are more to lerant to a wider range of s a l i n i t i e s than F_. i r r e g u l a r e . c. Rate of Water Loss - When f i r s t exposed, macroscopic plants of P. i r r e g u l a r e lose water very r a p i d l y . La ter , water loss progresses more slowly ( F i g , 88 and 90). There i s a con-siderable v a r i a t i o n in the loss of weight at d i f f e r e n t temper-atures , : and with an increase i n temperature a corresponding increase i n the d e s i c c a t i o n rate occurs ( F i g . 88). In la te -90-spring (May) there i s a conspicuous dif ference between the rate of water loss of plants from the upper and lower i n t e r t i d a l region . This same d i f f e r e n t i a l i s not found i n e a r l y spring ( A p r i l ) . As shown i n Figure 89, there i s a pronounced di f ference i n the rate of water loss of the blades and holdfas ts of P. i r r e g -ulare , f o r the holdfas ts lose water more slowly than the blades . The slow rate of water loss f o r the upper i n t e r t i d a l plants i n la te spring i s probably due to the small number of \blades present at t h i s t i m e . ( F i g . 88). In la te spr ing the higher plants are v i s i b l y more stunted than the lower ones. The loss of water from intac t plants i n nature i s quite v a r i a b l e , and i s no doubt re la ted to di f ferences i n r e l a t i v e humidity, temperature, shading, p r o t e c t i o n , and aggregation of Individuals ( F i g . 90). In one experiment there was more than kO percent d i f ference i n the t o t a l water loss (after f i v e hours) , between corresponding plants i n the sun and i n the shade ( in shadow of large boulder ) . A f t e r f i v e hours of exposure i n the f i e l d , the plants in the sun l o s t 8k percent of t h e i r o r i g i n a l damp-dried weight ( F i g . 90) d. Resistance to Desicca t ion - Most blades of P_. i r r e g u l a r e die i f they lose kO to 60 percent of t h e i r damp-dried weight. One blade was a l i v e a f t e r approximately 75 percent dehydration, but most showed at least some sign of damage a f t e r kO percent dehydration ( F i g . 91). The data f o r the holdfas ts were i n s u f -f i c i e n t to determine the percent of water loss that i s l e t h a l , but four specimens were a l i v e a f t e r 6k to 68 percent dehydration. - 9 1 -e. L e t h a l D e s i c c a t i o n Time of Germlings - Young germlings are very s e n s i t i v e to d e s i c c a t i o n ; they die most q u i c k l y at high temperatures and i n d i r e c t s u n l i g h t . The l e t h a l d e s i c c a t i o n times determined are as f o l l o w s : (1) 90 minutes at 5°C i n the shade, (2) 60 minutes at 10°C i n the shade (3) k-0 minutes at 27°C i n the shade, and (li) 10 minutes at 27°C i n d i r e c t s u n l i g h t . f . S u r v i v a l i n the Dark - No germling growth takes place i n t o t a l darkness beyond the one to two-cel led stages, but germ-l i n g s can withstand prolonged periods of darkness and s t i l l be v i a b l e . In one experiment, three weeks old germlings were s t i l l capable of growth upon t ransfer to proper i l l u m i n a t i o n a f t e r being i n t o t a l darkness f o r two months. Holdfasts have been retained i n darkness f o r longer periods (four months) and were s t i l l capable of g i v i n g a p o s i t i v e TTZ t e s t . 3. Discussion of Tolerance Experiments Both germlings and mature plants of P_. i r regulare are t o l e r -ant to a wide range of temperatures. The l e t h a l temperature f o r ,_,o germlings is approximately 35 C, and f o r the macroscopic p l a n t s , o 39 to aO G; both l e t h a l temperatures are much greater than the maximum a i r temperatures recorded during 1962 (2[L°C) near G l a c i e r Point . B i e b l (1962a,b) reports s i m i l a r f i n d i n g s f o r temperate and t r o p i c a l algae, and states that the d i f f e r e n t i a l between the required and ac tual heat tolerances i s much less i n the t ropics (maximum sea temperature 28°C) than on the north coast of Prance (maximum annual sea temperature approximately 1 6 . 5°C). The heat resistance of t r o p i c a l submerged algae i s 32 to 35°C, whereas that of temperate algae i s 27 to 30°C. -92-B i e b l ' s r e s u l t s are not comparable to those recorded f o r P. i r r e g u l a r e , because he recorded the v i a b i l i t y of plants a f t e r twelve hours exposure to a p a r t i c u l a r temperature. The l e t h a l temperatures recorded f o r P. i r r e g u l a r e are thus higher than any of the l i m i t s he d e f i n e s . In any event, the extreme temperature tolerance of P. i r regulare i s probably not e c o l o g i c a l l y s i g n i f i -cant . Although the l e t h a l temperature of blades var ies with the s a l i n i t y , i t i s u n l i k e l y that t h i s phenomenon i s very important i n nature, f o r i t only occurs at very high temperatures. Under such extreme temperatures, only plants i n the more optimal s a l i n -i t i e s (30 to kO ° / o o ) s u r v i v e . B i e b l (1962b) has suggested that species i n h a b i t i n g various l e v e l s on the shore have d i f f e r e n t l e t h a l temperatures. A s i m i -l a r trend ex is ts f o r several of the more common plants at G l a c i e r P o i n t , but no di f ference has been recorded between specimens of P_. i r regulare c o l l e c t e d from d i f f e r e n t l e v e l s . Also no di f ference was noted between t ide pool and non-tide pool p l a n t s . I n t e r t i d a l algae are exposed to a wide range of s a l i n i t i e s due to evaporation and r a i n f a l l . According to B i e b l (1962b), most i n t e r t i d a l algae withstand immersion in a concentration range of 0.1 to 3 . 0 times that of seawater f o r 2k hours , while a few tolerate 0 to k.O times seawater f o r 2k hours. Algae of the lower i n t e r t i d a l region and t ide pools are less r e s i s t a n t and resemble s u b t i d a l algae, few of which can to lera te a s a l i n -i t y range greater than 0 .5 bo 1.5 times that of seawater. A f t e r 2k hours , the usual range of s a l i n i t y tolerance f o r macroscopic plants of P_. i r r e g u l a r e i s 0 to 95 ° / o o or 0 to 3 .2 times that - 9 3 -of seawater. This corresponds c l o s e l y to the l i m i t s defined by B i e b l (1962b) f o r most i n t e r t i d a l algae. / As described e a r l i e r , some of the young blade i n i t i a l s and holdfas ts can withstand s a l i n i t i e s of 0 to 130 ° / o o , or 0 to 3 .8 times seawater f o r 2k hours . A few older blades may be injured a f t e r 2k hours i n f r e s h water, but they are never completely k i l l e d a f t e r 2k hours. On the whole, i t would seem that holdfas ts are more r e s i s t a n t to extreme s a l i n i t i e s than blades . The ac tual s a l i n i t y tolerance of macroscopic plants i s much greater than any of the surface water s a l i n i t i e s recorded at G l a c i e r Point , but i t i s d i f f i c u l t to evaluate the changes of s a l t concentration due to evaporation. It i s evident that t h e i r ac tual tolerance i s probably greater than the s a l i n i t y tolerance required i n nature. In c u l t u r e , macroscopic plants of P. i r r e g u l a r e can t o l e r -ate a wide range of s a l i n i t i e s , but they do not grow in extreme s a l i n i t i e s . A f t e r 25 days i n one experiment, plants were s t i l l l i v i n g i n s a l i n i t i e s of 6 to 79 ° / o o . Such r e s u l t s correspond w e l l with the photosynthesis and r e s p i r a t i o n rates of the macro-scopic plant at d i f f e r e n t s a l i n i t i e s , since no conspicuous di f ferences are recorded f o r r e s p i r a t i o n and photosynthesis at s a l i n i t i e s of 20 to l\.0 ° / o o . The s a l i n i t y tolerance of germ-l i n g s from unispores af ter 35 days i s 5 to 70 ° / o o , and t h i s i s comparable to that of the macroscopic plants a f t e r 25 days. The s a l i n i t y tolerance of germlings from p l u r i s p o r e s a f t e r 35 days i s 5 bo 55 % o , which i s less than that of the unispore germlings. -9k-According to B i e b l (1962b), many t h i n green and brown algae accumulate s a l t s against a d i f f u s i o n gradient , and thereby p r e -vent the onset of p l a s m o l y s i s . The c e l l s of other plants may r e s i s t plasmolysis because of t h e i r high c e l l u l a r osmotic values . Several other means of avoiding plasmolyt ic damage i n hypertonic solut ions are discussed by.the same author. If the c e l l s of P. i r r e g u l a r e become plasmolyzed, the plants die very q u i c k l y . The calcium content of the medium may influence the hypertonic resistance of marine algae, since the resistance of severa l algae increases wi th the calcium content. This may be corre la ted with the fac t that a calcium d e f i c i e n c y causes a rapid loss of potas-sium from the c e l l s ( B i e b l , 1962b). Experimental studies have v e r i f i e d the hypothesis that blades of P_. i r r e g u l a r e are extremely s e n s i t i v e to water l o s s . Although the l e t h a l dehydration values of blades and holdfas ts may not be conspicuously d i f f e r e n t , there Is a d i s t i n c t d i f f e r -ence i n rate of water l o s s , because blades lose water much more r a p i d l y than h o l d f a s t s . Such a d i f f e r e n t i a l d e s i c c a t i o n rate provides a greater degree of p r o t e c t i o n f o r the h o l d f a s t . Chapman and Trevarthen (1957) have referred to such a phenomenon as one of " n a t u r a l p r o t e c t i o n . " This p r o t e c t i o n , and the greater s a l i n i t y tolerance of the h o l d f a s t s , may p a r t i a l l y e x p l a i n why the holdfast i s more to lerant to exposure than the blades . As discussed e a r l i e r , G a i l (1918) states that the mature plants of Fucus evanescens w i l l not to lera te prolonged periods of t o t a l darkness. In contras t , Boalch (1961) states that c u l -tures of Ectocarpus confervoides remain v i a b l e a f t e r 100 to 150 -95-days of t o t a l darkness. According to Kain (196LL) the gameto-phytes of Laminaria hyperborea are also tolerant to darkness (60 days at 5 ° C ; 50 days at 1 0 ° C ; and L L O days at 17 ° C ) . Her resul ts suggest that temperature may be important i n deter -mining the v i a b i l i t y of gametophytes i n darkness. Both the germlings and h o l d f a s t s of P_. i r r e g u l a r e can also withstand prolonged periods of darkness and they must do so i n order to ex is t i n a sandy h a b i t a t . -96 V I . GENERAL DISCUSSION AND CONCLUSIONS As described e a r l i e r , very few c o l l e c t i o n s of P_. i r r e g u l a r e have been made u n t i l r e c e n t l y , and the species has been known only from a few l o c a l i z e d areas other than B o l i n a s , C a l i f o r n i a and Cape Arago, Oregon. Recent c o l l e c t i o n s from C a l i f o r n i a , Washington, B r i t i s h Columbia, and A l a s k a , which have not been reported e a r l i e r , extend the known range from Point Conception, C a l i f o r n i a to Khantaak Island near Yakutat, A l a s k a . Pigure 1 shows the l o c a l i t i e s where i t i s known to occur, and Table XV l i s t s voucher specimens f o r each l o c a l i t y . Although the d i s t r i -bution of P. i r r e g u l a r e on the P a c i f i c Coast of North America is extremely sporadic , i t i s not discontinuous and i t s apparent d i s t r i b u t i o n probably r e f l e c t s the lack of extensive c o l l e c t i o n s i n some areas. In any event, i t i s not a common p l a n t , as only three populations are known from A l a s k a , eleven from B r i t i s h Columbia, two from Washington, s ix from Oregon and nine from C a l i f o r n i a (Table X V ) . Pigure 92 shows the oceanographic conditions at G l a c i e r Point and several other l o c a l i t i e s on the P a c i f i c Coast of North America w i t h i n the d i s t r i b u t i o n a l range of P_. i r r e g u l a r e . The mean monthly temperature varies from about 5.6 to 16.5°C, whereas the mean monthly s a l i n i t y var ies from 29.5 bo 3 k . l ° / o o . The gross d i s t r i b u t i o n of P. i r regulare i s no doubt c o n t r o l l e d by temperature, f o r i t i s not found south of Point Conception, C a l i f o r n i a (Dawson, 1958, 1959b), where the temperatures often exceed 20°C. Laboratory experiments confirm that the 20°C -97-maximum summer isotherm i s probably a c r i t i c a l one f o r growth and reproduction of P_. i r r e g u l a r e „ The optimal temperature f o r photosynthesis and growth i s between 13.5 to l 5 . 0 ° C , but at 20°C the rate of photosynthesis and growth decreases. No f e r -t i l e germlings are produced at 20°C. The average monthly temperatures at A t t u I s l a n d , Alaska (near the known northeastern l i m i t s of P. i r r e g u l a r e ) range from about 2.6 to 10°C. At 2.6°C the rate of growth and reproduction would be very l i m i t e d , but at 10°C plants could survive as well as those at G l a c i e r P o i n t . The occurrence of P. i r regulare on A t t u Is land, A l a s k a , suggests that i t may also occur i n Japan. If so, i t might have been con-fused e a r l i e r with Petalonia d e b i l i s . Segawa (1959) records Petalonia d e b i l i s from several locat ions i n Japan. S e t c h e l l (1893* 1917, 1935) was one of the f i r s t to sug-gest that the geographic d i s t r i b u t i o n of marine algae could be explained on the basis of seasonal and l a t i t u d i n a l d i f ferences i n temperature. S e t c h e l l (1893) d ivides the surface waters of the P a c i f i c Coast of North America from Alaska to Mexico into four zones; the b o r e a l , temperate, s u b t r o p i c a l and t r o p i -c a l according to the 10, 15* 20 and 25°C maximum summer i s o -therms. Most species are only found i n one zone, severa l are i n two, very few are i n three, and only r a r e l y are any i n a l l f o u r . On t h i s b a s i s , P. i r r e g u l a r e is a eurythermal species since i t occurs i n both the boreal and temperate zones of the P a c i f i c Coast of North America. Scagel (1963) suggests that 7 A eurythermal species is one that grows i n a wide range of temperatures, while a stenothermal species grows i n a r e -s t r i c t e d range of temperatures. many more middle i n t e r t i d a l species can extend over a wider range than s u b t i d a l and lower i n t e r t i d a l species , because the former are more f l e x i b l e and tolerant of greater extremes. Tolerance experiments conducted i n the laboratory tend to sub-s tant ia te t h i s f o r _P. i r r e g u l a r e . Most populations of P_. i r regulare occur i n exposed or semi-exposed coasta l areas, and the plant does not appear to extend into i n l e t s . Several specimens of P_. i r regulare have been found near Yakutat , Alaska (Table XV, UBC #939h, 9801), where the s a l i n i t i e s range from 20 to 2$ ° / o o (Anon. 1962a). It i s p o s s i -ble that these condit ions are rather l o c a l i z e d and do not e x i s t near populations of P. i r regulare at Khantaak Island near Yaku-t a t . The s a l i n i t i e s near Yakutat are much lower than any r e -corded at G-lacier P o i n t . However, i n any event, s a l i n i t y i s probably not a l i m i t i n g f a c t o r on most open coasta l areas, but i t may be r e g i o n a l l y s i g n i f i c a n t where there i s considerable runoff of f r e s h water. I n a b i l i t y of the plant to reproduce under low s a l i n i t i e s may r e s t r i c t i t from i n l e t areas. R e s p i -r a t i o n and photosynthesis of the macroscopic plant of P_. i r regulare does not appear to be adversely af fec ted under ^Low s a l i n i t i e s (20 ° / o o ) . The necessi ty f o r wave ac t ion may also be important during the growing season of P. i r r e g u l a r e . The low n i t r a t e concentration of seawater i n Southern C a l i f o r n i a may r e s t r i c t i t s southern d i s t r i b u t i o n . Tibby and Terry (1959) record extremely low n i t r a t e values at or near the surface from Santa Barbara, C a l i f o r n i a to Point Conception, C a l i f o r n i a (0 to 0.15 ug-at N 0 - / 1 ) . The highest N/P r a t i o -99-recorded from the cont inenta l shel f area of Southern C a l i f o r n i a was 2.8/1 , and t h i s was from a very deep water sample taken near Point Conception. The phosphate values recorded by the same workers are also w e l l below the optimal concentrations determined i n the labora tory . However, i t i s possible that the nutr ient requirements at a high temperature may be somewhat lower than those at a low temperature. Thus, the nutr ient requirements at Point Conception may be somewhat lower than those recorded i n the labora tory . L i t t l e i s known of the n i -t rate concentration of waters i n the northern part of B r i t i s h Columbia and A l a s k a . The phosphate values recorded by Scagel (1961) in Queen Charlotte S t r a i t are probably representative of other areas i n northern B r i t i s h Columbia, and they are com-parable to those recorded at G l a c i e r P o i n t . Scagel (1963) emphasizes that there is a high degree of uniformity of algae along the P a c i f i c Coast under s i m i l a r con-d i t i o n s of temperature and substrate . However, the d i s t r i -bution of P. i r r e g u l a r e i s extremely sporadic , which suggests that other condit ions must be very important i n determining i t s l o c a l occurrence. Five d i f f e r e n t populations of P. i r r e g u -lare have been observed i n B r i t i s h Columbia and Washington (Fig . 1), and i n each area the plants are r e s t r i c t e d to sandy h a b i t a t s . A l l a v a i l a b l e information indicates there i s a large amount of sand i n a l l other l o c a l i t i e s where JP. i r r e g u l a r e grows. ( F i g . 1 ) . Hence, sand i s apparently a dominant environmental f a c t o r . The suggestion of Richards (1932) concerning exceptional =100° habitats seems very p e r t i n e n t , f o r he states that one should "study the exceptional habitat where the influence of c e r t a i n „8 factors are shown i n an extreme degree. If other condit ions are not l i m i t i n g , the dominant fac tor w i l l be the c o n t r o l l i n g one. Thus, the sporadic d i s t r i b u t i o n of P. i r r e g u l a r e can be explained by the presence or absence of sand. Although the gross d i s t r i b u t i o n of P. i r r e g u l a r e i s no doubt re la ted p r i -mari ly to temperature, other condit ions seem to be more im-portant i n determining i t s r e g i o n a l d i s t r i b u t i o n . As discussed e a r l i e r , any perennial plant which grows i n a sandy habi ta t comparable to that at G l a c i e r Point must be adapted to extreme reduct ion i n l i g h t i n t e n s i t y , severe abrasion, and prolonged submergence i n sand. Experimental studies upon P_. i r r e g u l a r e show that i t i s wel l adapted to a sandy h a b i t a t , p a r t l y because optimal l i g h t i n t e n s i t i e s f o r macroscopic plants and germlings are very low, and both can survive prolonged periods of darkness. The low r e s p i r a t i o n rate of macroscopic plants i s no doubt an advantage i n a sandy h a b i t a t , because i t sustains the plants u n t i l the sand cover i s removed. It i s also suggested that the " d i r e c t -type" of development found f o r P_. i r r e g u l a r e may be an advan-tage i n a sandy h a b i t a t . Since the plant i s g e n e t i c a l l y adapted to survive i n a sandy area, an Incomplete a l t e r n a t i o n of generations must insure successive generations of g e n e t i -c a l l y s i m i l a r p l a n t s . __5  Richards (1931) statement quoted from Doty (1957). 1 0 1 -The morphology of the blades of P_. i r r e g u l a r e i s extremely var iable and the blades are very sens i t ive to d e s i c c a t i o n . The range of v a r i a b i l i t y of non-t ide pool plants observed at G l a c i e r Point overlaps with that described f o r P_. australe from C a l i f o r n i a , Thus, P. australe is considered to be nothing more than a growth form of P. i r r e g u l a r e and i s synonymous. D i s t r i b u t i o n a l evidence supports t h i s conclus ion , f o r there i s no marked geographic d i s c o n t i n u i t y between the populations at Point Conception and B o l i n a s , C a l i f o r n i a , -102 = V I I . SUMMARY The developmental morphology and l i f e h i s t o r y of P. i r r e g u -lare are discussed i n d e t a i l . P l u r i l o c u l a r sporangia and paraph-yses are described f o r the f i r s t time from the laminate t h a l l i ; p r e v i o u s l y , only u n i l o c u l a r sporangia were recorded. Unispores and p l u r i s p o r e s develop i d e n t i c a l l y , and each i s capable of p r o -ducing a laminate t h a l l u s immediately or a f te r a succession of d i s c o i d and filamentous p l e t h y s m o t h a l l i . The l i f e h i s t o r y of P. i r r e g u l a r e i s of the " d i r e c t - t y p e , M which may be due to a sup-press ion of meiosis i n the u n i l o c u l a r sporangium. Morphological and c u l t u r a l evidence i s presented to support t h i s hypothesis . F i e l d studies suggest that the filamentous p l e t h y s m o t h a l l i may not e x i s t i n nature, but i t has been impossible to prove. On the other hand, i r r e g u l a r discs can apparently develop as rhizome-l i k e structures from the holdfas ts of macroscopic plants i n nature. The growth and occurrence of P. i r r e g u l a r e have been studied at G l a c i e r Point i n r e l a t i o n to environmental fac tors (sand f l u c -t u a t i o n , t i d e s , s a l i n i t y , n u t r i e n t s , and meteorological c o n d i t i o n s ) . At G l a c i e r P o i n t , P. i r r e g u l a r e i s r e s t r i c t e d to rocks i n sandy areas, and the greatest number of plants i s found where gross f l u c -tuations of sand occur annually . A d e t a i l e d study of the a l g a l associat ions i n sandy and rocky habitats was made, and i t i s e v i -dent that the algae present i n each area are very d i f f e r e n t . Two perennial plants besides P. i r r e g u l a r e are apparently r e s t r i c -ted to sandy areas at G l a c i e r Point - A h n f e l t i a concinna and Gymnogongrus l i n e a r i s . A l l three species have an incomplete -103-a l t e r n a t i o n of generations^ which may be of advantage i n a sandy h a b i t a t . F i e l d studies suggest that competition between other plants probably r e s t r i c t s P„ i r regulare to sandy areas, because i t w i l l grow i n rocky areas i f other algae are e l i m i n a t e d „ The growth and reproduction of P. i r r e g u l a r e at G l a c i e r Point i s l i m i t e d to the period of sand removal, which var ies from s i x to eight months per year 0 The period of maximum growth (Feb-ruary to A p r i l ) i s associated wi th a corresponding increase i n l i g h t i n t e n s i t y and water temperature. A f t e r A p r i l , the growth i n non-tide pool populations decreases much more r a p i d l y than that i n t ide p o o l s . The decrease i n growth of the' non-t ide pool plants a f te r A p r i l i s probably caused by increased dayl ight t i d a l exposures, since the number of dayl ight exposures i s much greater i n la te spring to summer than i n the winter . The per iod of de-creased growth f o r the t ide pool populations occurs l a t e r (May to June) than that f o r non-t ide pool populat ions , and i t i s probably caused by high surface water temperatures, h igh l i g h t i n t e n s i t i e s or a combination of both. The blade morphology of t ide pool and non-tide pool populations i s extremely v a r i a b l e , and the range of v a r i a b i l i t y of P_. i r r e g u l a r e observed at G l a c i e r Point overlaps with that described f o r P_. a u s t r a l e . J?„ australe i s therefore considered a growth form of P. i r r e g u l a r e and i s synonymous. D i s t r i b u t i o n a l evidence a lso supports t h i s c o n c l u s i o n . Laboratory experiments were conducted upon the germlings and macroscopic plants of P. i r r e g u l a r e i n order to determine the major fac tors i n f l u e n c i n g growth and d i s t r i b u t i o n i n natura l -10k-h a b i t a t s . The known d i s t r i b u t i o n a l range of P, irrfegulare i s from Point Conception, C a l i f o r n i a to Khantaak Is land near Yaku-t a t , A l a s k a , The primary f a c t o r c o n t r o l l i n g i t s gross d i s t r i -bution i s bel ieved to be temperature. S a l i n i t y i s probably, not a l i m i t i n g f a c t o r on most open coastal areas, but i t may be r e g i o n a l l y s i g n i f i c a n t . L i t t l e i s known of the n i t r a t e and phos-phate concentration of seawater i n northern B r i t i s h ' C o l u m b i a , but they would not seem to be l i m i t i n g f o r the growth of P, i r r e g u l a r e , On the other hand, the nutr ients a v a i l a b l e i n the seawater of Southern C a l i f o r n i a are probably l i m i t i n g . I t i s suggested that the sporadic d i s t r i b u t i o n of P„ i r r e g u l a r e can be explained by the presence or absence of sand. Thus, l o c a l condit ions seem to be most important i n determining the regional d i s t r i b u t i o n of £.» i r r e g u l a r e , Several features are discussed to expla in how the plant i s adapted to a sandy h a b i t a t . Macroscopic plants are more to lerant than germlings to ex-tremes of temperature, s a l i n i t y , and d e s i c c a t i o n , but the actual temperature and s a l i n i t y tolerances f o r both appear to be much greater than that required i n nature. This i s not so f o r r e s i s -tance to d e s i c c a t i o n of the macroscopic plants and the germlings. The germlings die a f te r a very short period of d e s i c c a t i o n , where-as the blades die a f te r k O to 60 percent dehydration. The blades are apparently p h y s i o l o g i c a l l y d i s t i n c t from the h o l d f a s t s , f o r holdfas ts are more r e s i s t a n t to extreme c o n d i t i o n s . -io5-V I I I . BIBLIOGRAPHY Abe, K. 1935a. Zur Kenntniss der Entwicklungsgeschichte von Heter6chdrdaria 9 'Seytosiphon und Sorocarpus. S c i . ' R e p o r t s Tohoku Imp. U n i v . Ser . k , B i o l . 9 : 3 2 9 - 3 3 7 s 6 f i g s s P I . 10. 1935b. Kopulat ion der Schwarmer aus u n i l o k u l a r e n Sporan-gium von Heterochordaria a b i e t i n a . I b i d . 10 : 2 8 7 - 2 9 0 , 2 f i g s . 1938° Entwicklung der Fortpflanzungsorgane und Keimungs-geschicte von Desmarestia v i r i d i s ( M u l l . ) Lamour. I b i d . 12:k75-k82, 6 f i g s . , P i . 3 9 . Anon. 1959. Observations of Seawater Temperature and S a l i n i t y on'the P a c i f i c Coast of Canada. V o l . XVIII , 1958. P i s h . R e s . B d , , Canada. Manuscript Rep. Ser . (Ocean, and Limn.) No. "k8.' 62- pp. 9 2 9 f i g s . P a c i f i c Oceanographic Group. . Nanaimo. 1962a. Surface Water Temperature and S a l i n i t y . P a c i f i c Coast, North and South America and P a c i f i c Ocean Is lands . U . S . Coast and Geodetic Survey P u b l . 31=*3» F i r s t e d i t i o n . 71 p p . , 2 t a b l e s . Washington, D . C . 1962b. Climate of B r i t i s h Columbia. Tables of Temperature, P r e c i p i t a t i o n , and Sunshine, Report f o r 1962. Metero l . Branch Canada, Dept. Transp, 53 PP .» V i c t o r i a . 1962c. P a c i f i c Coast Tide and Current Tables 1 9 6 3 . Canadian Hydrographic Service P u b l i c a t i o n , v i + 2 6 2 p p . , Ottawa, 1963. P a c i f i c Coast Tide and Current Tables 196k. Canadian Hydrographic Service P u b l i c a t i o n , v i 4- 2 8 0 p p 0 , Ottawa, B i e b l , R. 1962a. Temperaturresistenz Tropischer Meeresalgen (Verglichen mit jener von Algen i n temperierten Meeres-gebieten) . Bot, Mar, k ( 3 / k ) .2kl«25k, 3 f i g s . 1962b, Chapter 53. Seaweeds i n : R . A . Lewin (Ed.) Physiology and biochemistry of Algae, Academic Press , N.Y. and London, Pp. 799-815, 2 f i g s . , 2 t a b l e s . B l a c k l e r , H. and A . K a t p i t i a , 1963. Observations on the L i f e -H i s t o r y and Cytology of E l a c h i s t a f u c i c o l a . Trans. Bot. Soc, Edinburg . 39:392-393T"*" B l i n k s , L,R„ 1955. Photosynthesis and p r o d u c t i v i t y of l i t t o r a l marine 'algae . J . Mar, Res, l k ( l k ) , 3 6 3 - 3 7 3 , 3 f i g s , , 2 t a b l e s . -106-Boalch, G.T, 1961 0 Studies on Ectocarpus i n c u l t u r e „ II - Growth and n u t r i t i o n of a bac ter ia free c u l t u r e , J . Mar, B i o l , Ass , U . K . 1+1287-301+, 6 f i g s , , 1 t a b l e , Boyle , M. and M.S , Doty, 191+9. The tolerance of stenohaline forms to d i l u t e sea water. B i o l , B u l l , 97s232„ Broekhuysen, G , J , 191+0, A pre l iminary Invest igat ion of the importance of d e s i c c a t i o n , temperature and s a l i n i t y as fac tors c o n t r o l l i n g the v e r t i c a l d i s t r i b u t i o n of c e r t a i n i n t e r t i d a l marine gastropods i n False Bay s South A f r i c a . Trans. Roy. Soc. South A f r i c a . 28(3)^255-292, 6 f i g s . , 1 1 ' t a b l e s . Burrows, E , M . 1958. Some c r i t i c i s m s of present day a l g a l e c o l -ogy, III Int . Seaweed Symp. Pp, 2 7 - 2 8 . Galway, I re land, Caram, B„ 1957. Sur l a sexualite ' et le developperaent dV une Phaeophycee% Cylindrocarpus b e r k e l e y i (Grey,) Crouan, Compt. Rend. A c a d „ ~ S c i . (Paris) 21+5 J kk®=141-3* 1 f i g . Chapman, V . J , 191+2, Zonation of marine algae on the sea shore. Proc. -Linn. Soc. Lond. 151+:239-252, 1+ f i g s , , 2 t a b l e s . 1961. The Algae . Macmillan & Co. L t d . v i i + 1+72 p p . , 229 f i g s „ , 26 t a b l e s . 1962. A c o n t r i b u t i o n to the ecology of Egregia laeviga ta S e t c h e l l . Part I - Taxonomic status and morphology, Bot. Mar, 3(1/2) %33-1+5, 1+ f i g s . , 1 t a b l e , 3 p l . Part II -D e s i c c a t i o n and groivth. I b i d . 3(1/2) :L+6--55£. 7 f i g s . . , 2 t a b l e s . Part III - Photosynthesis and r e s p i r a t i o n ; conclusions . I b i d . 3 (3/1+) .'101-122, 7 f i g s O J ; 9 t a b l e s . Chapman, V . J . and C 0 B , Tre.varthen. 1957. L ecologie d^Hormo-s i r a banks i i . Ins Ecologie des algues marines, C o l l o q . Int . Centre Nat, Rech. S c i . , P a r i s , Pp, 231-21+8, 18 f i g s . Clendenning, K . A . and M„C. Sargent. .1957. Physiology and Biochemistry of Giant K e l p . Quarter ly Rept, Kelp I n v e s t i -gation Program^, U n i v . C a l i f , Ins t . Mar. Resources. 57-=6, p„ 29 (not seen), C l i n t , H . B . 1927. The l i f e h i s t o r y and cytology of Sphacelar ia bipinnata Sauv„ P u b l , Har t ley Bot . Lab„ U n i v . L i v e r p o o l , N o T T i i r ^ * 51 f i g s . Cooper, L . H . N , 1937. On the r a t i o of ni t rogen to phosphorus i n the sea. J . Mar„ B i o l . Ass , U . K , 22;177-182 9 k t a b l e s . Cotton, A . D , 1912. Glare Island Survey. P t . 15 p Marine Algae . Proc. Roy. I r i s h Acad, 31:1-178, 11 p i s . - 1 0 7 -Dammann, H. 1 9 3 0 . Entwicklungsgeschichtl iche und zytologische Untersuchungen an Helgolander Meeresalgen. Wiss . Meeres-untersuch. A b t . Helgoland, N . P . 18(1+) „ 3 6 p p . , 2 2 f i g s . , 1 p l . Dangeard, P. 1 9 6 3 a . Recherches sur le cycle e v o l u t i f de quelques Scytosiphonacees. Le Botanis te . 1+6 (fasc I - I I ) ; 5-129, 2 1 p i s . 1 9 6 3 b . Sur le developpement de Punctaria l a t i f o l i a G r e v i l l e recolte ' dans le Bassin d Arcachon.' Le Botaniste . l|.6(fasc 6 ) : 2 0 5 - 2 2 l i , 3 p i s . 1961+. Le plethysmothalle ^a sporocytes u n i l o c u l a i r e s de Peta lonia z o s t e r i f o l i a . Phycologia l+(l) il-$-l89 1 f i g . Dawson, E.Y„ 1 9 5 8 . Notes on P a c i f i c Coast marine algae V I I . B u l l . So. C a l i f . Acad. S c i „ 57(2 ) :6£-80, 12 f i g s . , i n c l . P l . 20-21+. 1 9 5 9 a . A Primary Report on the Marine F l o r a of Southern C a l i f o r n i a . In Oceanographic Survey of the Continental Shelf Area of Southern C a l i f o r n i a . P u b l . No. 2 State ( C a l i f . ) Water P o l l u t i o n C o n t r o l Bd. M u l t i l i t h . Sacra-mento. Pp. 169-261L, IL6 f i g s . , 1 t a b l e . 1 9 5 9 b . T h i r d Annual Report, Benthic Marine Vegetat ion. In Oceanographic Survey of the Continental Shelf Area of Southern C a l i f o r n i a . P u b l . No. 3 , State ( C a l i f . ) Water P o l l u t i o n Control Bd. M u l t i l i t h . Sacramento. Pp. 1 2 5 - 1 6 9 . Doty, M.S. 191+6. C r i t i c a l t ide fac tors that are corre la ted with the v e r t i c a l d i s t r i b u t i o n of marine algae and other organisms along the P a c i f i c Coast. Ecology 2 7 ( I I ) S 3 1 5 - 3 2 8 , 6 f i g s . 191+7° The marine algae of Oregon. Part I . Chlorophyta and Phaeophyta. Far lowia 3 ( l ) : l - 6 5 , 1 0 p i s . 1 9 5 7 . Chapter 1 8 . Rocky I n t e r t i d a l Surfaces . Ini J.W. Hedgpeth (Ed)„ Treat ise on Marine Ecology and Paleoecology. V o l . I , Ecology. G e o l . Soc. Am. Mem. 6 7 . Pp. 5 3 5 - 5 8 5 * 18 f i g s , 2 t a b l e s . E l l i o t , E . and B. Moss. 1 9 5 3 . Incidence of meiosis i n the l i f e cycle of H a l i d r y s s i l i q u o s a Lyngb. Nature. 1 7 1 s 3 5 7 • F0yn, B 0 R , ( < 1931+. Uber den Lebenscyklus e i n i g e r Braunalgen. Vor lauf ige M i t t e i l u n g . Bergens Mus. Arbok 1931+. 9 pp. 108-F r i t s c h , F , E e 19k2» Studies i n the comparative morphology of the algae. Part I I . The a l g a l l i f e c y c l e . Ann. Bot . 6 ( 2 k ) : 5 3 3 - 5 6 2 s 1 f i g . 191+5. The Structure and Reproduction-of the Algae . Cambridge, V o l . I I , x i v + 939 pages. 336 f i g s , . 2 maps. G a i l , F,W. 1918, Some experiments wi th Fucus to determine the fac tors c o n t r o l l i n g i t s v e r t i c a l d i s t r i b u t i o n , P u b l , Puget Sound B i o l , Sta , 2.139-151* 6 t ables , 1 chart , Gibbs, D„C, 1939. Some marine a l g a l communities of Great Com-brae . J 4 E c o l , 27:361+-382, 2 F i g s . , 7 t a b l e s . H a r r i e s , R, 1932. An i n v e s t i g a t i o n by c u l t u r a l methods of some of the fac tors i n f l u e n c i n g the development of the gametophytes and e a r l y stages of the sporophytes of L a m i n a r i a ' d i g i t a t a , L , saccharina , and L , c l o u s t o n i . Ann, B o t . . Lond, 1+6:893-928, 35 f i g s , , 16 t a b l e s . Hasegawa, Y, 1962, An e c o l o g i c a l study of Laminaria angustata Kjellman on the coast of Hidako P r o v , , Hokkaido, B u l l . Hokkaido Reg. F i s h 0 Res, Lab, 21+: 116-138 (not seen). Hauck, F . 1883-1885. Die Meeresalgen Deutschlands und Oester-r i c h s . In: L , Rabenhorst, Kryptogamen F l o r a von Deutsch-l a n d , O e s t e r r i c h und der Schweiz, 2nd ed, Bd„ 2. x x x i i i + 575 P P ° , 236 f i g s . j 5 p i s . L e i p z i g : E , Kummer, Haxo, F . T . and L , R, B l i n k s , 1950. Photosynthetic ac t ion spectra of marine algae, J , Gen, P h y s i o l , 33:389-1+22, 22 f i g s , Hedgpeth, J.W. 1957. Chapter 19. Sandy Beaches, In : J.W. Hedgpeth (Ed), Treat ise on Marine Ecology and Paleo-ecology. V o l , 1, Ecology, Geol , Soc. Am, Mem, 67. Pp. 587-608. 1 1 ' f i g s , 1 t a b l e , Hollenberg , G , J , 1 9 k l , Culture studies of marine algae. Part I I . Hapterophycus c a n a l i c u l a t a S, & G. Amer. J . Bot. 28?676-653, 16 f i g s . Hygen, C . 193k. Uber den Lebenszyklus und die Entwicklungs-geschichte der Phaeosporeen, Versuche an Nemacystus  d i v a r i c a t u s (Ag,) Kuck, Nyt. Mag, Naturvidensk, 7k:187-268 11 f i g s „ , 16 p i s , K a i n , J . M . 196k. Aspects of the biology of Laminaria hyper-borea. Part I I I , S u r v i v a l and growth of gametophytes. J . Mar. B i o l , A s s . U . K . 1+1+: 1+15-1+33 s 10 f i g s . Kanda, T , 1936. On the gametophytes of some Japanese species of Laminar ia les . S c i , Pap, I n s t , Algae . Res. Fac , S c i , Hokkaido Imp. U n i v . 1 (2) :221-260, 27 f i g s . , P i s , k 6 - k 8 . -109-Kemp, L , and K. C o l e . 1961. Chromosomal a l t e r n a t i o n of gener-ations i n Nereocystis luetkeana (Mertens) Postels and Ruprecht. Can, J , Bot. 39:1711-1721]., 51 f i g s . Kniep, H. 1907. Be i trage zur Keimungsphysiologie und B i o l o g i e von Fucus. Jahrb. Wiss . Bot. l+l+:'635-72l+, 12 f i g s . 1911)-. Ueber die A s s i m i l a t i o n und Atmung der Meeresalgen. Internat . Rev. H y d r o b i o l . 7•1-38. (not seen). Knight , M, 1923. Studies i n the E c t o c a r p a c e a e „ Part I . The l i f e h i s t o r y and cytology of P y l a i e l l a l i t t o r a l i s K j e l l m . Trans. Roy. Soc. Edinburgh. ^3s 31+3-360, 6 p i s . 1929. Studies i n the Ectocarpaceae, I I . The l i f e -h i s t o r y and cytology of Ectocarpus si l lculosus> D i l l w , I b i d . 56s307-332, 3 f i g s s 6 p i s . " Knight , M„ and M,W„ Parke. 1931. Manx algae. L i v e r p o o l Marine' B i o l . Comm. Mem. 30 . L i v e r p o o l . 155 P P ° S 1 t a b l e , 2 maps, 19 p i s . Knight , M., M . C . H . B l a c k l e r and M.W, Parke, 1935. Notes on the l i f e cycle of species of Asperococcus, Trans, L i v e r -pool B i o l . Soc. h,8s79-97» 3 f i g s , , 1 t a b l e , Kornmann, P, 1951+. G-iffordia fuscata (Zan„ ) Kuck, nov, comb., eine Ectocarpacee mit heteromorphen, homophasischen Generationen, H e l g o l . Wiss . Meeresunters, Bd„ 5 (H, l ) s 1+1-52., 5 abb, 1962. Die Entwicklung von Chordaria f l a g e l l i f o r m i s , I b i d . Bd, 8(H.2)£276-279, 3 abb. K y l i n , H. 1916. Uber den Generationswechsel bei Laminaria d i g i t a t a . Svensk. Bot. T i d s k f i f t . 102551-561, 5 f i g s . 1933. Uber die Entwicklungsgeschichte der Phaeophyceen. L u n d s U n i v . I r s s k r . N .P . A y d . 2 , 2 9 ( 7 ) . 102 p p . , 35 f i g s , , 2 p i s . I93I+0 Zur Kenntnis der Entwicklungsgeschichte e i n i g e r Phaeophyceen, I b i d . ' 30(9.). 19 pages, 10 f i g s . 1937. Bemerkungen uber der Entwicklungsgeschichte e i n i g e r Phaeophyceen. I b i d . 3 3 ( 1 ) . 31+ pages, 5 f i g s . Levyns, M.R. I933» Sexual reproduction i n Macrocystis p y r i f e r a A g . Ann. Bot . 1+7:31+9-353* 9 f i g s . Mathias, W,T„ 1935. The l i f e h i s t o r y and cytology of Phloeo-spora brachiata Born, P u b l . Hart ley Bot, Lab. U n i v . L i v e r p o o l , No. 13:1-23, 52 f i g s . , 1 diagram. -110-M u l l e n , J . B . and J . P . R i l e y , 1955. The spectrophotometry determination of n i t r a t e i n natura l waters with p a r t i c u -l a r reference to sea water. A n a l , Chim, A c t a . 27:l+6k» k80, 2 f i g s , 7 t a b l e s . ; Murphy, J . and J . P . R i l e y , 1962. A modified s i n g l e s o l u t i o n method f o r the determination of phosphate i n natura l waters. A n a l . Chim, A c t a , 27.31-36, 1 f i g . * 3 t a b l e s . Myers, M . E . 1928. The l i f e h i s t o r y of the brown a l g a , Egregia m e n z i e s i i . U n i v . C a l i f . P u b l . Bot , l k . 225-2k6, i n c l . PI . k9-57. Naylor , M. 1955. The l i f e h i s t o r y of Adenocystis u t r i c u l a r i s . (Bory) H. et H . Trans. Roy. Soc. New Zealand. 53(2); 295-301, k f i g s . , 3 P i s . Neushul, M, 1963. Studies on the giant kelp Macrocyst is . Part I I ; Reproduction. Amer, J , Bot, 50(k)%35k~359 s 6 f i g s , , 1 t a b l e . Parke, M„ 1933=- A c o n t r i b u t i o n to knowledge of the Meso-gloiaceae and associated f a m i l i e s . P u b l . Har t ley Bot . Lab. Univ . L i v e r p o o l , No, 9, 1+3 P P . , 20 f i g s . , . 11 p i s . Rabinowitch ,•E„ 1956. Photosynthesis and Related Processes. V o l . 2, p t . 2, In tersc ience , New York, x v i + 1211-2088 p p . , i l l u s . 38.k f i g s . R e d f i e l d , A , C . 1931+. On the Proportions of Organic Der iva t ives i n Sea Water and t h e i r Rela t ion to the composition of Plankton. James Johnstone Memorial Volume, L i v e r p o o l U n i v . Press . 31+8 pp. (not seen). Rees, T . K . 1935. The marine algae of Lough Ine, J . E c o l . 23;69-133, 2 f i g s , 1 map. Reinke, J . I878. fiber die Entwicklung von P h y l l i t i s n Sc^to-siphon und Asperococcus. Jahrb. Wiss . Bot. l l;2olf-273. Richards , P.W. 1932. Ecology. In Pr , Verdoorn (Ed.)., Manual of Bryology, Martinus N i j h o f f , The Hague. Pp. 367-395<> 5 f i g s . (not seen), R i l e y , G . A . , H . Stommel and D , P , Bumpus. 19k9. Quanti tat ive ecology of the plankton of western northern A t l a n t i c , B u l l . Bingham Oceanog, C o l l . 12(3);1-169, 39 f i g s . , 2k t a b l e s . R i t c h i e , D. 1957. S a l i n i t y optima f o r marine fungi af fec ted by temperature. Amer. J . Bot . kk;870=87k, 6 f i g s . - I l l R i t c h i e , D„ 1959° The e f f e c t of s a l i n i t y and temperature ..on . marine and other f u n g i from various c l imates , • "• B u l l , 7 Torrey Bot, C l u b , 86(6) :367-373, 5 figs. ' . : S a i t o , Y. 1956a. An e c o l o g i c a l study of Undaria' p i n n a t i f Ida; Sur, Part I„ On the influence of 'enVirbnm.ehtal^adtdr upon the development of gametophytesv> ' B u l l i Jap,'Soc... S c i . P i s h , ' 22(1L):229-23IJ., 6 f igs ' . , ' 1 1 p l , ' . ' : ' ., >\.' :^' ; 1956b. An e c o l o g i c a l study of Undaria p i n n a t i f I d a S u r . . Part I I , On the influence of environmental fac tors upon the maturity of gametophytes, and e a r l y development of sporophytes. I b i d , 22(LL) : 2 3 5 - 2 3 9 , 5 f i g s , 1956c, An e c o l o g i c a l study of Undaria p i n n a t i f i d a Sur, Part I I I , On the e f f e c t s of l i g h t i n t e n s i t y and temper-ature upon the rate of photosynthesis,, (-1). I b i d , 2l+(6) :l+81j.-l+86, 2 f i g s , 1 Sanborn, E . I . and M.S . Doty 19LLLL0 The marine algae of the Coos Bay-Cape Arago region of Oregon, Oregon State Monogr, Studies i n B o t . , No, 8. 66 p p . , 1+ p l s „ , 1 map, Sauvageau, G, 1918„ Recherches sur les Laminaires des Cotes de Prance. Me'm, Acad, S c i , P a r i s , 56:1-21+0, 85 f i g s . 192l+a„ Sur le curieux developpement d une algue Pheo-sporee Castagnea zosterae Thuret , Compt. Rend. Acad. S c i . (Paris) 179 :T3HT^ l381+, 1 f i g , 192i+b„ Sur quelques exemples d heteroblas t ie dans le developpement des algues Pheosporees, I b i d . 179: .1576-1579 o 1929. Sur le developpement de quelques Pheosporees. B u l l . S t a t . B i o l . Arcachon. 26s253-1+20, 20 f i g s . Scagel , R . F . 1961. The d i s t r i b u t i o n • o f c e r t a i n benthonic algae i n Queen Charlotte S t r a i t , B r i t i s h Columbia, i n r e l a t i o n to some environmental f a c t o r s . P a c i f i c S c i . I5:l|-9l+-539s 51 f i g s , 1 t a b l e , I .963 . D i s t r i b u t i o n of attached marine algae i n r e l a t i o n to oceanographic conditions i n the northeast P a c i f i c , Ppc 3 7 - 5 0 , 11 f i g s . In M . J . Dunbar (Ed,) Marine D i s t r i -but ions , Royal Soc. Can, S p e c i a l Publ , No. 5° Univ , Toronto Press , i n cooperation with Roy. Soc, of Canada, (8) + 110 p p . , i l l u s . Sehussnig, B. and E . Kothbauer. t > 1931+. P e r Phasenwechsel von Ectocarpus s i l i c u l o s u s . Osterr . Bot. Z e i t s c h r , 83: 81-97^ 1+ f i g s . -112 = Segawa, 'S„ 1959, Colored I l l u s t r a t i o n s of the Seaweeds of Japan, Chome Uehonmachi, Osaka, Japan, x v i i i 4- 175 pp„ , 8k p i , S e t c h e l l , W.A. 1893, On the c l a s s i f i c a t i o n and geographic' d i s t r i b u t i o n of the Laminariaceae, Trans , Conn, Acad, Arts and S c i , 9 : 3 3 3 - 3 7 5 . 1917. Geographical d i s t r i b u t i o n of marine algae. Science . 1+5 s 197-20k. 1935-° Geographic elements of the marine f l o r a of the north P a c i f i c Ocean, Amer. Nat, 69.560~577» S e t c h e l l , W.A; and N . L , Gardner, 192k, Phycologica l c o n t r i -but ions , V I I . U n i v . C a l i f . Publ , Bot, 1 3 ( 8 ) . 1 - 1 3 . 1925. The "marine algae, of the P a c i f i c Coast of North America,, Part I I I , Melanophyceae. Univ . C a l i f . P u b l . Bot. 82383-898, i n c l . P I . 3k-107. Shepard, P . P . I 9 k 8 , Chapter V . Beaches and Sand S h i f t i n g Along the-Shores, In P .P , Shepard, Submarine Geology (1st e d 0 ) , Harper Press , New York, Pp, 80-10k, i n c l . P i g . 32-1+2. Smith, P „ E , 1951 o Tetrazolium s a l t . Science.. 113:751-751+. Smith s G.M. 19kk 0 Marine Algae of the Monterey Peninsula . Stanford U n i v . Press, S tanford . i.x + 622 pp, 98 p i s , Stephenson, T . A . 1 9 k 2 „ The causes of the v e r t i c a l and h o r i -zontal d i s t r i b u t i o n of organisms between tide marks i n S o u t h ' A f r i c a . P r o c L i n n . Soc. Lond, l 5 k : 2 1 9 - 2 3 2 , 1 f i g , S'tocker, 0 , and W, Holdheide. 1938. Die A s s i m i l a t i o n Helgo-lander Geseitenalgen wahrend Ebbezei t , Z e i t s c h r , Bot, 32s 1-59, 1 9 f i g s , , 3 t a b l e s . Sundene, 0, 1962. The impl ica t ions of transplant and culture-experiments on the growth and d i s t r i b u t i o n of A l a r i a ejaculenta. N y t t . Mag, Bot, 9sl55=-17k, 8 f i g s , 1 " table , 6 p i s . Svedel ius , N, 1 9 2 8 . On the number of chromosomes i n the two d i f f e r e n t kinds of p l u r i l o c u l a r sporangia of Ectocarpus vij^escens, Thur. Svensk, Bot, T i d s k r . 22s289-30ka 4 f i g s . Sverc-rup, H . U , , M.W, Johnson and R . H . • Fleming. 191+6, The Oceans t h e i r Physics , Chemistry, and General Biology , P r e n t i c e - H a l l , I n c . , N.Y. x + I O 8 7 p p . s 265 f i g s , , 1 2 1 t a b l e s , 7 char ts . -113-Tibby, R . B . and R . D . Terry„ 1959. P h y s i c a l and Chemical C h a r a c t e r i s t i c s of the Waters over the Southern C a l i f o r -n i a " S h e l f , ' 1 ;95D-1958O Inorganic N u t r i e n t s , In Oceano-graphic Survey of the Cont inental Shelf Area of Southern C a l i f o r n i a . P u b l . No. 2 State ( C a l i f . ) Water P o l l u t i o n Control Bd. M u l t i l i t h . Sacramento. Pp. 117-168, 27 f i g s . , 3 t a b l e s . TJeda, S. 1929. On the temperature i n r e l a t i o n to the develop-ment of the gametophytes of Laminaria r e l i g i o s a Miyabe-. Journ. P i s h . I n s t . , Tokyo. 2k:138-139. Van Der Veen, R. and G. M e i j e r . 1959. L ight and plant growth. P h i l i p s ' G l o e i l a m p e n f a b r i e k e n , Eindhoven, H o l l a n d , x i x + 162 p p . , 92 f i g s . Whitaker, D„M. and C.W. Clancy. 1937. The e f f e c t of s a l i n i t y upon the growth of eggs of Fucus f u r c a t u s . B i o l B u l l . 73:552-556. 1 f i g . Widdowson. T„B. 1959. Some aspects of the i n t e r t i d a l ecology of marine organisms on Vancouver Island between V i c t o r i a arid Por t 'Renfrew. '•M.A. T h e s i s , U n i v . of B r i t i s h Columbia, i x + 16k, k9 f i g s . , 8 t a b l e s . APPENDIX I . Tables I-XV TABLE I Summary of Culture Media (a) Enriched Seawater (after Boalch, 1961) Seawater l i t e r KNO 202 mg 3 K.HPO. 31+. 8 mg 2 k Fe C l .6H 2 0 2.7 mg ? Mn C l . k H 2 0 0.2 mg (b) Phosphate Series Seawater l i t e r KNO^ 202 mg K 2 HP0 k 1+.1+ to 3k. 8 mg Fe C l ,6H 2 0 2.7 mg Mn C l . k H 2 0 0.2 mg (c) N i t r a t e Ser ies Seawater l i t e r KNO^ 10.1 to 202 mg K 2 H P 0 k 3k.8 mg Mn C l . kH 2 0 0.2 mg Fe C1.6H 2 0 2.7 mg TABLE II Denuded Transect #1 (Refer to Pigure 16, area k) Date February 20, 1963 March 29, 1963 A p r i l 27, 1963 May 27, 1963 June 8, 1963 June 20, 1963 November k, 1963 November 18, 1963 December 29, 1963 January 12, 196k February 26, 196k Observations Denuded; i n s i t u plants Phaeostrophion  i r r e g u l a r e , P e t r o c e l i s f r a n c i s c a n a , A h n f e l t i a p l i c a t a and Lithothamnion sp. Mostly diatoms (Amphipleura s p . , T h a l a s s i o -s i r a r o t u l a , and M e l o s i r a spTT l impets (Acmaea sp . ) and barnacles . Diatoms (mostly M e l o s i r a s p . , Amphipleura &_£.), Spongomorpha spinescens, Urospora  w o r m s k i o l d i i , Enteromorpha l i n z a , Porphyra  p e r f o r a t a , barnacles , l impets . R a l f s i a f u n g i f o r m i s , Porphyra p e r f o r a t a , barnacles , l impets . Porphyra p e r f o r a t a , R a l f s i a f u n g i f o r m i s , l i m p e t s , barnacles . Sand-covered u n t i l at l e a s t October 21, 1963 ( f o r t n i g h t l y observations made between June 20 and October 21). Sand cover completely removed. Nothing v i s i b l e . Diatoms (Amphipleura sp. ]• and young discs of P. i r r e g u l a r e evident . Well developed blades of P. i r r e g u l a r e e v i -dent. Largest blades 33 mm l o n g , average length 15 mm. A p r i l 27, 196k Largest blades 70 mm l o n g , several f e r t i l e . TABLE III Denuded Transect #2 (Refer to Figure 16, area 1) Date March 29, 1963 A p r i l 27, 1963 May 25, 1963 June 8, 1963 June 20, 1963 November k, 1963 November 18, 1963 December 29, 1963 February 26, 196k A p r i l 22, 196k Observations Denuded; _in s i t u plants Phaeostrophion  i r r e g u l a r e and diatoms.. Completely covered with Urospora wormski-o l d i i , small amount of diatoms (Amphi-pleura s p . ) . Diatoms (Amphipleura .sp_.), Porphyra p e r f o r -a ta , Enteromorpha l i n z a , Haplogloia Ander-s o n i i , Pe ta lonia d e b i l i s . Diatoms, Monostroma fuscum, Enteromorpha  l i n z a , Haplogloia andersonii and Peta lonia  d e b i l i s . Sand-covered u n t i l at leas t October 21, 1963 ( f o r t n i g h t l y observations made between June 20 to October 21, 1963). Sand cover completely removed. Diatoms (Amphipleura s p . , M e l o s i r a s p , ) , and young discs of P. i r r e g u l a r e evident . Wel l developed blades (18 mm long) on several basal h o l d f a s t s ; some holdfas ts over 13 cm i n diameter and no blades . Largest blades 30 mm l o n g ; blades not i r r e g u l a r l y t o r n . Largest blades 85 mm l o n g , i r r e g u l a r l y t o r n ; most f e r t i l e plants with p l u r i l o c u -l a r sporangia. TABLE IV Denuded Transect #3 (Refer to Figure 16, area 6) Date A p r i l 26 , 1963 May 26, 1963 June 8 , 1963 June 20 , 1963 November I I , 1963 November 18, 1963 December 1, 1963 December 29 , 1963 January 12, 196k February 26 , 196k A p r i l 27, 196k O b s e r v a t i o n s Denuded; almost e x c l u s i v e l y Phaeostrophion  i r r e g u l a r e and few diatoms. Urospora w o r m s k i o l d i i , Spongomorpha s p i n -escens, Porphyra lanceola ta , diatoms (Amphi-pleura s p . 9 Melosira s p . , e t c ) , few c h i t i n s . Diatoms (Amphipleura sp. e t c ) , Urospora  w o r m s k i o l d i i . Sand-covered u n t i l at leas t November 1, 1963. Sand cover completely removed, nothing observed growing. Sand covered the denuded t ransec t . Sand completely removed, nothing observed growing. Few d i s c o i d germlings of P_. i r r e g u l a r e present; l a r g e s t about 2 cm i n diameter, no blades . Blades evident ; average len gth 10 mm. P. i r r e g u l a r e very abundant forming dense mat on some port ions of denuded t ransect ; average blade len gth 18 ram. Several blades i r r e g u l a r l y t o r n , few f e r t i l e ; average frond length 30 mm, some up to 75 ram. TABLE V Sand Analy; Mesh Size mm Z_ 0.1k9 0.1k9 0.208 0.250 0.59 0.8k 1.981 Av. % (12 samples) 11.95 % 17.09 % 3I4-. hS % 15.17 % 9.k8 % 9.30 g 2.56 $ T A B L E V I T i d a l F a c t o r s a t G l a c i e r P o i n t , 196a ( f t ) J a n F e b M a r A p r i l HHHW 10.8 10.1 9.1+ 9 . k HLHW 8.5 8.5 8.5 8 . k MHHW 9.6 9.3 8.8 8.6 MLHW 7.7 7.7 7.7 7.5 LHHW 8.5 8.5 8 . k 8.0 L L H W 5.8 5.9 6.3 6.7 HHLW 8.0 7.8 7.6 7.6 H L L ¥ 5.1 5.3 k . 8 14--3 MHLW 7.1 6 . k 5.9 6.1 M L L ¥ 2.7 3.2 3-5 3.0 L H L W 5.5 5.1 k.k k.$ LLLW. .9 1.7 2.3 1.5 M a y J u n e J u l y A u g 10.0 10.k 10.5 10.1 7.9 8.1 8.0 7.9 8.9 9.0 8.9 8.8 7.1 7.0 7.0 7.0 7.8 7.9 7.8 7.9 6.2 5.k 5.3 5.3 7.6 7.1*. 7.3 7.1 k.k If.5 k.k k . 3 6.2 6 . k 6.2 5.6 2 . k 2.2 2 . k 2.6 k . 8 5.0 k . 9 k . l • k -.1 -.1 .5 M e a n S e a L e v e l - 6. 22 f t S e p O c t N o v D e c M e a n 9.2 9.6 10.5 11.2 10.1 8.2 8.0 8.2 8.5 8.2 8.5 8.5 9.1 9.5 9.0 7 .k 7.5 7.3 7.3 7 .k 8.0 7.7 8.0 8.3 8.1 5.9 6.5 6 . k 5.9 6.0 7.2 7. If 7.9 8.0 7.6 3.7 i f . l h.k If.5 If.If ,5.5 5.7 6.2 6.6 6.2 2.7 2.7 2.6 2 .k 2.7 i f . l 3.7 k . O ^ 9 k . 6 1.3 .5 .3 0.9 D a t a t a k e n f r o m A n o n 1963. TABLE VII Maximum and Minimum D a i l y Exposure Periods (mih) f o r Various T i d a l Levels (0.5 to 5.0 f t ) at G l a c i e r Point Date Feet 1958 March" 0.5 1.0 1.5 2.0 2.5 30-1+5 3.0 105-11+2 3.5 1+5-202 l+.O 1+5-277 105-365 5.0 127-375 A p r i l 15-1+5 30-168 1+5-217 52-270 105-315 120-375 75-51+0 May 30-60 1+5-135 1+5-195 1+5-21+0 75-285 1+5-31+5 75-375 90-I+12 11+2-1+65 June 67-11+2 67-161 120-206 82-21+7 90-300 15-330 120-367 120-I+08 105-I+50 255-505 J u l y 75-90 15-157 95-210 75-290 30-31+5 105-1+05 120-500 195-555 Aug 30 60-112 15-180 30-230 1+0-277 75-318 187-370 137-I+20 Sep 15-1+5 15-150 1+0-230 1+5-312 120-1+57 225-597 Oct 75-105 30-165 25-210 25-262 30-300 67-337 105-390 150-1+35 Nov 15-30 25-120 1+5-202 15-21+0 30-292 60-338 90-390 60-1+1+5 172-I+90 Dec 1959 Jan 75 90-105 97-157 15-205 50 1+5-21+7 15-135 82-280 25-195 1+5-320 1+5-225 1+5-380 82-277 150-1+05 90-368 160-1+97 135-1+80 Feb 60 1+5-157 52-202 30-270 90-322 67-367 11+2-1+05 60-1+65 March 75-135 75-210 105-277 21+0-31+5 285-120 337-1+95 -«-March 6-31, 1958. Calculated Columbia, from'hourly coordinates recorded March, 1958 to March, 1959 at Sooke,' B r i t i s h TABLE VIII L i s t of Plants Present i n Areas 6 a , 6 b , and 7 6 a 6 b 7 PHAE OPHYGEAE A l a r i a nana Schrader x x A l a r i a marginata Postels and Ruprecht x x x Collodesme" b u l l i g e r a Stroemfelt x x Desmarestla herbacea Lamourdux x x D. v i r l d i s (Muller) Lamouroux x Egr egia menzies I i (Turner) Areschoug subsp. m s n z i e s i i x Fucus evanescens C. Agardh f'. evanescens x l x Haplogloia andersonii (Parlow) Levring x2 x2 x2 Hedophyllum s e s s i l e (C. Agardh) S e t c h e l l x x x He11evOchordaria ablet iha (Ruprecht) S e t c h e l l and Gardner x x x Laminaria c u n e i f o l i a J . Agardh f . c u n e i f o l i a x x x Laminaria ephemera S e t c h e l l x Laminaria s e t c h e l l i i S i l v a x Leathesia di f formis ' (Linnaeus) Areschoug x LessOniOpsis l l t t o r a l i s (Parlow and Setchel l ) Reinke x x Nereocystis" luetkeana (Mertens) Poigtels and Ruprecht x x Peta lonia d e b i l i s : (C. Agardh) Derbes and S o l i e r x2 x2 x2 Phaeo3t"roplaion Irregulare S e t c h e l l and Gardner x x R a l f3 l a fungiformis (Gunnerus) S e t c h e l l and Gardner x x R. ' p a c i f i c a Hollenberg _.. x x x Scytosxphon bullosus Saunders x S . l ome n't ar i a (Lyngby e) J . Agardh f . lomentarla x2 Soranthera "ulvoidea Postels and Ruprecht f . u lvoidea x Sphacelaria racemosa G r e v i l l e x x Keys x l = plants only found in sandy areas on very h igh rocks . x2 = t ide pool p l a n t s . TABLE VIII (Cont'd) 6 a 6 b 7 CHLOROPHYCEAE Cladophora trichotoma (CV Agardh) Kutzing x2 oodidlum gregarium A . Braun x x Codium s e t e h e l l i Gardner x2 C b l l i n s i e l l a jtuberculata S e t c h e l l and Gardner x2 Ehteromorpha l i n z a " (Linnaeus) J . " Agardh x x x Monostroma fuscum (Postels and Ruprecht) Wittrock x x x f , fuscum • " M. g r e v i l l e i (Thuret) Whittrock x2 M» oxyspermum (Kutzlhg) Doty x2 M« z o s t e r i c o l a T i l d e n . " x Spohgomorpha c o a l i t a (Ruprecht) C o l l i n s x S. spiheseeh'g Kutzing x x U l v a fehestrata Postels and Ruprecht x x Urospora varic ou veriana (Tilden) S e t c h e l l ' a n d Gardner x x Urospora wormskioldii (Mertens) Rosenvinge x x x RH ODOPHYCEAE A h n f e l t i a concinna J . Agardh x x A . p l i c a t a (Hudson) Pries x2 x x Bahgia fusc opurpurea (D i l lwyn) Lyngbye x x x B o s s i e l l a " corymbifera (Manza) S l l v a x2 x2 x2 Call i thamnioh pikeanum Harvey var . pikeanum x C a l l o p h y l i s crenulata S e t c h e l l x C o r a l l l n a o f f i c i n a l i s ' v a r . c h i l e n s i s (Harvey) Kutzing x2 x x £ . vane Ouve r i e ns i s Yendo var . c h i l e n s i s (harvey) x2 x2 x2 Kutzlhg ""^ "~" Dermatolithon dispar (Foslle) Posl ie x. D l l s e a c a l i f o r h i c a (J . agardh) Kuhtze x x x Endocladia muricata (Harvey) J . Agardh x l x Table VIII (Cont'd) 6a 6b 7 Eirythrophy Ilum delesseriodes J . Agardh x Farlowia mol l i s (Harvey and Bailey) Farlow and S e t c h e l l x2 x2 x2" Gigar t ina p a p i l l a t a (C. Agardh) J . G . Agardh x x x G l b i o p e l t i s furcata .(Postels and .Ruprecht) J . Agardh x Grateloupia c a l i f o r n i c a K y l i n x Gymhogongrua""! iriearis (Turner) J . G . Agardh x Halosaccion glandiforme (Graelln) Ruprecht x x x Hymenena f l a b e l l i g e r a (J . Agardh) K y l i n x Iridophycus heterocarpum (Postels and Ruprecht) x x x S e t c h e l l and Gardner M i c r o c l a d i a b o r e a l i s Ruprecht x2 x x Nemalion helmiritholdes (Velley) Batters x Odonthalia f l o c c o s a (Esper) Palkenberg x l x x2 P e t r o c e l i s f ranciscana S e t c h e l l and Gardner x x x Pike a pinna t'a S e t c h e l l x Plocamium pacificum" K y l i n x" x P1 oc"amioc61 ax" pulv 1 nata S e t c h e l l x x Porphyra hereocystis Anderson ' x P. perforata J . Agardh f . perforata x x x P. "variegata" (Kjellman")' Hus x P r i o n i t i s lanceolata Harvey x2 x2 x2 P. l y a l l i Harvey x2 x2 x2 Pterosiphonia bipinnata (Postels and Ruprecht) x2 Palkenberg var . bipinnata " P t i l o t a f i l l c i h a " ( P a r l o w ) J . Agardh x2 x2 x2 P. hypnoides;Harvey x2 Rhodomela"larix (Turner) C . Agardh x x Smithora naiadum (Anderson)' Hollenberg x2 Phyllospadix s c o u l e r i Hooker x x TABLE IX Transect of Areas 6 a and 6 b ( 1 to 5 f t )"* May 2 3 , 1 9 6 3 A l a r i a marginata Postels arid' Ruprecht Coilbdesme b u l l l g e r a Stroemfelt Hedophyllum s e s s i l e (G. Agardh) S e t c h e l l Halosaccidn glandiforme (Gmelin) Ruprecht Monostroma "fuscum (Postels and Ruprecht) Wittrock f . fuscum Heterochbrdia abie t lna (Ruprecht) S e t c h e l l and - " G a r d n e r Spongomorpha c o a l i t a (Ruprecht) C o l l i n s C o r a l l i r i a vancouveriens i s Yendo Porphyra perforata J . Agardh f . perforata B o s s i e l l a corymblfera (Mariza) S i l v a Haploglola andersonii (Parlow) Levring G i g a r t i n a p a p i l l a t a (C. Agardh) J . G . Agardh Laminaria c u n e i f o l i a J . G . Agardh f . c u n e i f o l i a Iridophycus heterocarpum (Postels and Ruprecht) S e t c h e l l and Gardner Microcladia" boreal is Ruprecht Plocamium pacif icum K y l i n P t i l o t a f i l i c i n a "CFarlow) J . Agardh Enteromorpha l i n z a (Linneaus) J . Agardh 3 5 . 6 6a 6b (m2) (m2) Rat io 7.29 3 8 . 8 5 . 3 3 / 1 6 . 1 2 1 . 0 7 2 6 . 3 0 5 - 8 8 / 1 2.95 1 3 . 7 5 3 . 2 7 2.1+8/1 1 . 0 1 . 3 k 7 . 8 3 5 7 . ^ / 1 3".kO 9.89 2.91/1 5 . 7 5 3 3 . 5 5 . 7 2 / 1 0 . 7 1 3 3 . 5 9 5 .ok/i 0 . k l 7 1 . 1 3 5 0 . 8 3 3 k . 2 5 5 . 1 0 / 1 0 . 3 5 3.81 2 7 . 5 0 . 2 0 8 -"-Density f igures were constructed by t o t a l i n g number of i n d i v i d u a l s p e r ' p l o t , and then taking the averages over v e r t i c a l distance i n which species occupied. TABLE X S u r v i v a l of Unispores at Various S a l i n i t i e s and Temperatures, A f t e r 50 Days Temp oc 15 ° / o o 20 ° / o o S a l i n i t y ° / o o 25 ° / o o 30 ° / o o 35 ° / o o kO ° / o o 5°c 11.7 12.9 16.9 18.8 2k / 8.3 10°C 10.8 12.8 15.9 17.0 22-iO 19.5 I5°c 5 8,1 10.1 15.9 19.7 21.6 20°C 0 0 6 15 20 ; 22.0 S u r v i v a l Expressed as Percent TABLE XI Growth of Germlings Under D i f f e r e n t Light Q u a l i t i e s Maximum Transmittance (A*) of F i l t e r Age (Days) 3300-kOOG and 6000-8000. 3500 and 5750-8000 5500-8000 3750-k5O0 and 8000 3000,5250 and 7750 Control Pink Red Yellow Blue Green 10 65.3 63.85 69.25 6k. k7 85.17 89.88 W. 116.6 122.5 109.8 118.13 382.35 1+03.75 Growth of Germling Expressed as Length (u) TABLE XII A r t i f i c i a l Seawater (After Chapman, 1962) Compound Concentration Amount cc Na CI 28.39 gram i n £00 C c H 2 0 260.6 cc K CI 1 molar s o l u t i o n 5 Ca C l 2 1 " " 137 Mg C l 2 1 " " 3 .25 N a 2 SO. 1 " " l k . 5 Mix the solut ions and add water to make up to 1x20 cc . 80 cc of carbonate/bicarbonate b u f f e r i s added p r i o r to use. Buffer - .1 molar Na HCO^ • take 75 cc .1 molar Na CO, take 5 cc TABLE XIII Diethanolamine S o l u t i o n f o r C 0 2 Atmosphere 3g KHCO^ in to 10 cc of 60$ diethanolamine (2, 2' Imino diethanol) . f o r 2% CO t i o n . Make up to 15 m l . C0^ add k cc of HCl to o r i g i n a l solu-TABLE XIV P/R Ratios at D i f f e r e n t Temperatures Temperature Blade Holdfast 7.5°c k80/12.8 = 37.50 30/1.3 = 23.0 9.5 767/18.1 = 1+2.37 60/1.1 = 51+. 51+ 11.5 1110/21.15 = 52.1+ 75/2 i = 37.5 13.5 1620/26 = 62.30 no / 1 .5 = 73.33 15.5 1270/26.2 = 1+8.1+7 70/5 = l k . O 17.5 1000/28 = 35.71 20 680/28.5 = 23.8 67/5.5 = 12.1 TABLE XV Location • Alaska Khantaak Island (near Yakutat) Cape Sarichef (Uniraak Island) Chichagof Bay (Attu Island) B r i t i s h Columbia St r iae Islands Ashby Point (Hope Island) R o l l e r Bay (Hope Island) Cape S u t i l Experiment Bay (Cape Scott) Voucher Specimens of P. Approximate P o s i t i o n 59°35(N 5ii°37sN 5k0o5.5'N 5o°56.3'N 5o°56'K 50°52.5'N 50°k7!N 139°l|-6'W l6k°56«W 173°1 ' | ! E 132°l5.5fW 127°55^5'W 127°56fW I28°03 ,w 1 2 8 ° 2 £ ' W i r r e g u l a r e He rbarium Date and No. 7-8-60 UBC #939k 7-8-60 #9801 6-23-60 UBC #9807 6-9-6O UBC #95U5 6-2k-63 UBC #16278 6- 2k-63 #16314-5 7- 2-62 UBC #l5kl9 7-10-6k UBC #19155 7-2-62 UBC #15538 7-2-62 #15539 7-2-62 #15903 7-8-6I4. UBC #19365 Table XV (Cont'd) Location Winter Harbour Kelsey Bay Brooks Peninsula Tofino Box Island (Long Beach) G l a c i e r Point Washington Cat t le Point (San Juan Island) Ruby Beach Oregon Seal Rock Approximate P o s i t i o n 5 0 ° 3 1 f N 128°02«W 50 23 'N 125 58'W 50°07 'N 127°k2 'W k 9 ° 0 9 ! N 125°$k.'W k9°0k 'N 125°k7 'W k8°23'W 123°59'W k8°27 'N 122°57'W k7°k3 'N 12k°25'W kk°30'K 12ko05'W Date 5 - 31-59 6- k-59 6-k-59 5-28-59 5 - 28-59 6- 10-6k 6- 29-6k 7- 18-63 6-16-58 6-7-59 8-7-59 7-7-61 9-k-63 7-8-kl 7-8-kl Herbarium and No. UBC #10957 #1120k UBC #19909 UBC #kl57 #kl58 #19708 UBC #20019 UBC #20021 UBC #5096 #5760 #6781 UBC #20020 UBC #20022 M.S. Doty #2660' UC #696593 "M.S. Doty private herbarium. Table XV (Cont'd) Locat ion Coos Head Squaw Island (Cape Arago) Lighthouse Reef (Cape Arago) Cape Arago Cape Blanco H a r r i s Beach C a l i f o r n i a Bollnas Moss Beach Agassiz Beach (Hopkins Marine S t . ) Approximate P o s i t i o n IL3°20.5'N 12k°20'W k3°20.5'N 12k°21»W LL3°20 !K 12k°27»W 1L3°17 .5 'N 121L°25'¥ IL2°50.3'N 12k°3k«W k2°0k'N 12k°19 'W 37%3'N 122°k2«W 37°31'N 122°31'W 36°22«N 121°55'W Date 7-25-k2 7-19-kO 7-9-kl 7-27-k2 6- 21-39 5-191k 7- 2-kO 7-2-kO 5-19-58 5-1920 5-1920 k-9-k9 9-2k-kk Herbarium and No. AHPH #57k20 M.S. Doty #2k22 #2656 AHPH #57k21 M.S. Doty #2191 UC #276k98 M.S. Doty #2518 UC #69659k UBC #2835 UC #26k711 AHPH #8878* P . C . S i l v a #k99k*** M.S. Doty #6288 *Type of Phaeostrophion i r r e g u l a r e S. et G. -K-Prom type c o l l e c t i o n of Phaeostrophlon i r regulare S. et G. 45-*-«P.C. S i l v a private herbarium. Table XV (Cont'd) Approximate Herbarium Locat ion P o s i t i o n Date and No. B i g Sur (on A l v i n Dani Ranch.) 36°15'N 121°50'W 9-19-1+1 9-21-kl M.S. Doty #k011 #1+037 Piedras Blancas 35°i)-0'N 121°17.5'W 5-13-1+9 P . O . S i l v a #5.005 Estero Bay 35°23'N 120O53'W k-2-k7 AHFH #68k66 Pismo Beach 35°08'K 120°kO,W 5-16-k9 P . C . S i l v a #531k Point Sal 3i+°55'N 120°uO'W 5-11+-1+9 P . C . S i l v a #5126 Point Conception (Government Point) 3k°27rK 120°26»¥ 6-13-1+9 5-16-57 5-16-57 P . C . S i l v a #5516 AHFH #6k891* AHFH #6k892** ->I so type of Phaeostrophion australe Dawson. *-*Type of Phaeostrophion australe Dawson. APPENDIX I I . Figures 1-92 Figure 1 DISTRIBUTION OF PHAEOSTROPHION IRRE6UIARE S. EJ 6. ON THE PACIFlC COAST OF NORTH AMERICA 165 160 155 150 145 140 135 130 125 120 65 GULF OF ALASKA 55 175 CMchagof Bay , Alaska "5^ 130 ALEUTIAN IS. 175 60 55 Str iae Is. , B r i t i s h Co lu ib l a -QUEEN CHARLOTTE IS. BRITISH COLUMBIA Continuation of main pap Ashby Point , B r i t i s h Columbia. Experiment Bay , B r i t i s h Columbta -l l n t e r Harbour , B r i t i s h Columbia" .Brooks Peninsula , B r i t i s h Columbia VANCOUVER I Toflno , B r i t i s h Columbia — •Box I. , B r i t i s h Columbia . Glacier Point , B r i t i s h Columbia"' . Ruby Beach , Washington Rol ler Say , B r i t i s h Columbia Cape Su t l l , B r i t i s h Columbia Kelsey Bay , B r i t i s h Columbia Seal Rock , Oregon Coos Head , Oregon Lighthouse Reef , Oregon Cape Blanco , Oregon Harris Beach , Oregon 50 Cattle Point , Washington , UNITED STATES Squaw I. , Oregon 40 Bollnas , Ca l i fo rn ia Moss Beach , Ca l i f o rn i a Agasslz Beach , C a l l f o r n l a -B1g Sur , Ca l i f o rn ia Point Sal , C a l i f o r n i a -Point Conception , C a l t f o r n l a -Pledras Blancas , Ca l i fo rn ia Estero Bay , Ca l i fo rn ia Plsmo Beach , Ca l i f o rn ia * Actual Areas Observed by Investigator 165 160 155 150 145 140 135 130 125 120 Figure 2 Developmental Morphology of Macroscopic Stages of P. i r r e g u l a r e , i n s i t u Blades, 1 month o l d , a r i s i n g from h o l d f a s t , x 2 £ . Blades , 1-1/2 months o l d , a r i s i n g from h o l d f a s t , x2 .0 . C l u s t e r of blades , 2 months o l d , a r i s i n g from h o l d -f a s t (top view) , x0 .5. C l u s t e r of blades, 2 months o l d , a r i s i n g from h o l d -f a s t (side view), x0.5. Habit of mature plants i n t ide p o o l s , approximately k-5 months o l d (blades i r r e g u l a r l y t o r n ) , x0.5. Regeneration of blade from t o r n o f f p o r t i o n (arrow indica tes approximate p o s i t i o n of meristem), x0 .5. Regeneration of blade i n i t i a l s from old perennia l h o l d f a s t . Several o ld blades s t i l l v i s i b l e . xl3 g i Holdfast Morphology and Blade Development of P. i r r e g u l a r e Blade i n i t i a l s (knobs) o r i g i n a t i n g from old perennial h o l d f a s t s , x20. Older stage of blade regeneration showing f i n g e r - l i k e extensions and a young f l a t t e n e d blade , x20. Cross sec t ion of old holdfas t showing overlapping laye of old blades and d i s c s . Note conspicuous medullary f i laments i n blade remnants, x'75 Figure L Reproductive Morphology of P. i r r e g u l a r e Cross sect ion of a sorus of p l u r i l o c u l a r sporangia showing the appearance of the sporangia before and a f t e r zoospore discharge and s t e r i l e paraphysis . Note e l o n -gated c o r t i c a l c e l l s . x?80 Surface view showing p l u r i l o c u l a r sporangia and s t e r i l e paraphysis . Various developmental stages of the spor-angia are evident . x2300 Surface view of meristematic region showing i n i t i a l s of u n i l o c u l a r sporangia, xl+30. Mature u n i l o c u l a r sporangia and s t e r i l e vegetative c e l l s , x660. Unispore , top surface , x2600. Unispore, l a t e r a l view, x2600. P l u r i s p o r e , top surface , x2600. P l u r i s p o r e , l a t e r a l view, x2600. P l u r i s p o r e , lower surface xvith two c h l o r o p l a s t s , x2600. Surface view of reproductive sorus of blade showing u n i -l o c u l a r and p l u r i l o c u l a r sporangia together, xk30. Figure 5 Reproductive Morphology of P. i r r e g u l a r e a . Surface view showing developmental stages of u n i l o c u l a r sporangia, xliOO. b . Cross sec t ion of blade showing development of p l u r i -l o c u l a r sporangia, xlOOO. c. Cross sec t ion of blade showing mature p l u r i l o c u l a r sporangia, x800. d. Cross sec t ion of young blade showing d i f f e r e n t t i ssue regions and u n i l o c u l a r sporangia, x270. eQ Cross sec t ion of a somewhat older blade than i n Figure 5d, showing mature u n i l o c u l a r sporangia and a few e l o n -gated medullary c e l l s , xf>70. f . Enlargement of a s ingle u n i l o c u l a r sporangium with unispores , x900. Figure 6 Development of Unispores and Plur ispores a. Attached unispores which have l o s t f l a g e l l a and become s p h e r i c a l , 12 hours a f t e r l i b e r a t i o n (under phase con- •'• t r a s t ) , xlOOO. b . Attached plur ispores which have l o s t f l a g e l l a and become s p h e r i c a l . The f l a g e l l a are s t i l l v i s i b l e 12 hours a f t e r l i b e r a t i o n on the p l u r i s p o r e indica ted by the arrow (under phast c o n t r a s t ) . xlOOO c. D i s c o i d plethysmothallus , 1 day o l d , from a unispore , x l 8 5 0 . d. Filamentous plethysmothallus , 1 day o l d , from a unispore , x l 8 5 0 . e. D i s c o i d plethysmothallus , 1 day o l d , from a p l u r i s p o r e , x l 8 5 0 . f . Filamentous plethysmothallus , 1 day o l d , from' a p l u r i -spore, x l 8 5 0 . g . Filamentous plethysmothal lus , 2 days o l d , from a unispore , x l 8 5 0 . h , i „ Filamentous p l e t h y s m o t h a l l i , 7 days o l d , from unispores , x560. j . Filamentous plethysmothallus , 7 days o l d , from a p l u r i -spore, x560„ Figure 7 Filamentous and D i s c o i d Ple thysmothal l i a. Filamentous plethysmothallus , 20 days o l d , from a u n i -spore, x555. b. Adventi t ious o r i g i n of a disc from a 25 days old fi lament produced from a unispore , x555. c. Filamentous plethysmothallus , 38 days o l d , f rom a p l u r i -spore. Note wel l developed plethysmoplurisporangia , x555> d. Filamentous plethysmothallus , 15 days o l d , produced from a plethysmounispore ( f i r s t generat ion) , x555» e. Filamentous plethysmothallus , 15 days o l d , from a p l u r i -spore, x555. f . Filamentous plethysmothallus , 50 days o l d , from a u n i -spore. Note the empty plethysmounisporangia and p l e t h y s -moplurisporangia . New plethysmoplurisporangia are being produced w i t h i n the old ones, x670 g . Adventi t ious o r i g i n cf a disc from a 15 days old f i l a -mentous plethysmothallus from a unispore , x555. ' Figure 8 D i s c o i d Ple thysmothal l i a . D i s c o i d plethysmothallus , 10 days o l d , from a unispore , x560. b. D i s c o i d plethysmothallus , 10 days o l d , from a p l u r i s p o r e , x560, c. I n i t i a t i o n of a disc from the terminal end of a : 12 days old f i lamentjproduced by a unispore , x560. d. I n i t i a t i o n of a disc from the terminal end of a 12 days old f i lament , produced by a p l u r i s p o r e , x 5 6 0 . e. Filamentous plethysmothallus , 12 days o l d , from a unispore ( w i l l probably form a disc a d v e n t i t i o u s l y ) , x560. f . D i s c o i d p l e t h y s m o t h a l l i , 30 days o l d , from unispores . Two discs are connected together, and both are one layer t h i c k . xk30 g. Polystromatic d i s c o i d plethysmothallus , kO days o l d , from a unispore , x k 8 0 . Figure 9 F i r s t and Second Generations of D i s c o i d P l e t h y s m o t h a l l i , Intermediate Germlings, and I r regular Discs a. Polystromatic d i s c o i d p l e t h y s m o t h a l l i , 35 days o l d , from p l u r i s p o r e s , xklO, b . D i s c o i d plethysmothallus , 1±5 days o l d , from a unispore ( sess i le plethysmoplurisporangia) , x k l O . c. D i s c o i d plethysmothallus , 30 days o l d , from a plethysmo-unispore ( f i r s t generat ion) , x 5 k 5 . d. Intermediate plethysmothallus , liO days o l d , from a p l u r i -spore. Note the plethysmoplurisporangia . xklO e. Adventi t ious o r i g i n of a disc from a 30 day old f i l a -mentous plethysmothallus from a unispore , xklO, f . I r regular d i s c , k weeks o l d , from an unattached plethysrao t h a l l u s from a unispore , x l 6 0 . Figure 10 I r regular Discs I r regular d i s c , 6 weeks o l d , on an unattached plethysmo-t h a l l u s from a unispore , x 2 0 0 . I r regular d i s c s , 6 weeks o l d , i n a crowded culture of p le thysmothal l i from p l u r i s p o r e s , x l60 . I r r e g u l a r d i s c s , 8 weeks o l d , In a crowded culture of p l e t h y s m o t h a l l i from unispores , x l60 . Enlargement of i r r e g u l a r discs i n Figure 10c showing i r r e g u l a r p r o l i f e r a t i o n s of c e l l s , x6k0. I r regular d i s c , 10 weeks o l d , from an unattached p l e t h y s -mothallus of a p lur ispore (monosiphonous appendages s t i l l v i s i b l e ) , x250„ Young Hol d f a s t s of I \ i r r e g u l a r e from Culture and i n s i t u Young h o l d f a s t of macroscopic p l a n t , 5 months o l d , produced from a unispore i n c u l t u r e , xkO. Young h o l d f a s t of macroscopic p l a n t , 6-1/2 months old', produced from a unispore i n c u l t u r e (blade i n i t i a l s i n d i c a t e d with arrow), xk6. Young h o l d f a s t of macroscopic p l a n t , 6 months o l d , produced from a p l u r i s p o r e i n c u l t u r e (blade i n i t i a l s i n d i c a t e d w i t h arrow), xl±6. Young h o l d f a s t of macroscopic p l a n t , 6 months o l d , produced from a p l u r i s p o r e i n c u l t u r e (no blade i n i t i a l s v i s i b l e ) , x600. Young h o l d f a s t s of macroscopic pl a n t as found In natur-al, t h i s time the h o l d f a s t s are reminiscent cf young Figure 12 Blade I n i t i a l s of P. i r regulare and Petalonia d e b i l i s a s L o n g i t u d i n a l sec t ion of blade i n i t i a l developing from holdfast of P_„ i r r e g u l a r e . M a t e r i a l c o l l e c t e d i n f i e l d . xl2 b. Blade i n i t i a l produced i n culture from an 8-1/2 months old i r r e g u l a r d i s c , from a unispore , x25. C Blade i n i t i a l produced i n culture from a 1-1/2 years o ld d i s c o i d plethysmothallus , from a unispore , x350. d. Disc of Peta lonia d e b i l i s produced a f t e r LL5 days. Note o r i g i n cf blade from u n i s e r i a t e filament and hairs present on developing blade . x350 e. Disc of Peta lonia d e b i l i s , 30 days o l d , showing ear ly blade I n i t i a l s , x3£0. f„ Young blades of Peta lonia d e b i l i s growing e p i p h y t i -c a l l y upon P_. i r r e g u l a r e , x350. 4-Figure 13 Reproductive Organs on Cultured Germlings a a D e t a i l of plethysmounispores (within the sporangium) on a k weeks old germling from a unispore , xl7lS. b s I n i t i a l s of plethysmoplurisporangia on a 3 weeks old germling from a unispore , x800. c. Mature plethysmoplurisporangia on a k weeks old germling from a unispore , x 8 k 5 . d 0 L i b e r a t i o n of plethysmoplurispores from sporangium of same plant shown i n Figure 1 3 c , x770, e„ In s i t u germination of plethysmoplurispores i n germlings from p l u r i s p o r e s , x l l l l . f e Young i n i t i a l s of plethysmoplurisporangia on 33 days old germling from a p l u r i s p o r e , x 8 0 0 . Figure l k Reproductive Organs on Cultured Germlings a . Immature plethysmounisporangium on k weeks old germling from a unispore , x 8 0 0 . b. Mature plethysmounisporangium on 5 weeks o ld germling f r o m a unispore , x 8 0 0 . c s Immature plethysmounisporangia on 5 weeks old germling from a p l u r i s p o r e , x 8 0 0 . d 5 Nearly mature plethysmounisporangium on a 6 weeks o ld germling from a p l u r i s p o r e , x 8 0 0 . e. Surface view of mature plethysmounisporangia on a 5 weeks old disc from a unispore . Zoospores are emerging from sporangia. x 7 1 0 F i g u r e 1$ A Comparison of Surface C e l l Dimensions of Mature Blades from Base to Apex Figure 16 Generalized Life History of Phaeostrophion Irregulare S. et G, meiosis probably suppressed unilocular_ sporangia mature thallus plurilocular_ sporangia plurispores (probably 2n)~ -plethysmoplurispores plethysmoplurisporangia unispores discoid and filamentous ^ i r r e g u l a r or (probably 2n) plethysmothallus i regular disc plethysmounisporangia I -plethysmounisp ore s plethysmoplurispores plethysmoplurisporangia discoid and filamentous 'plethysmothalli plethysmoun -plethysmounispores irregular or regular disc sporangia F i g u r e 18 V a r i a t i o n o f S a n d L e v e l s i n A r e a s 6 a , a n d 6 b D u r i n g 1 9 6 k a , S a n d l e v e l s o n M a y l k , 1 9 6 k . b, Sand l e v e l s o n J u n e 2 6 , 1 9 6 k . Sand levels o n J u l y 1 1 , 1 9 6 k . d . S a n d l e v e l s o n S e p t e m b e r 3, 1 9 6 k . T h e s a n d d e p o s i t i o n d u r i n g t h i s y e a r w a s l e s s t h a n t h a t o f 1 9 6 2 - 6 3 . T h e a r r o w s i n d i c a t e t h e s ame r o c k f o r e a c h o f t h e s e p e r i o d s . " a " a n d w b " i n F i g u r e 1 8 a i n d i c a t e a r e a s 6 a a n d 6 b „ Figure 19 Variation of Sand Levels i n Area 6a, 196k a. Sand l e v e l s on A p r i l 30 7 196k. b. Sand levels on May l k , 196k. c. Sand leve l s on June 26, 196k. d. Sand leve l s on August 29, 196k. The arrows i n b-d indicate the same rock f o r each of these periods. The amount of sand present i n June i s t y p i c a l l y much higher than that shown f o r 196k. "a" is a s l i g h t l y d i f f e r e n t view than b-d. F i g u r e 2 0 V a r i a t i o n o f S a n d L e v e l s i n A r e a 6 b , 1 9 6 3 - 6 k a . S a n d l e v e l s o n A p r i l 1 6 , 1 9 6 k . b . S a n d l e v e l s o n A u g u s t 1 9 , 1 9 6 k . c . S a n d l e v e l s o n S e p t e m b e r k , 1 9 6 k . d . S a n d l e v e l s o n J u l y 2 0 , 1 9 6 3 . V e r y l i t t l e s a n d w a s p r e s e n t b y l a t e A u g u s t , 1 9 6 k , b u t b y e a r l y S e p t e m b e r o f t h e s ame y e a r a c o n s i d e r a b l e a m o u n t w a s p r e s e n t . U s u a l l y a r e a 6 b i s c o v e r e d b y J u l y ( n o t e d ) . \ Figure 21 Various Habitats on East Side of G l a c i e r Point a. General d i s t r i b u t i o n of plants i n area #2. The reduced occurrence of sand i s also evident (August 12, 196k)„ b . D i s t r i b u t i o n of sand and vegetation i n area #1 (June 26, 196k). c. Rhodomela l a r i x , Enteromorpha l i n z a p a r t i a l l y buried by sand i n area #1 (June 26, 196k). d t Por t ion of c showing d e t a i l s of p a r t i a l l y buried plants of Rhodomela l a r i x and Enteromorpha l i n z a . e. A s l i d e holder used f o r t ransplants of germlings. Figure 22 V a r i a t i o n of Sand Level on Area 6a, June 23 - December 1, 1963 8- 4 8 -20 H O R I Z O N T A L S C A L E I I N C H TO 4 F E E T V E R T I C A L S C A L E I I N C H T 0 2 F E E T 20 30 50 6 0 80 90 Figure 23 V a r i a t i o n of Sand Level on Area 6b, June 23 - November 17, 1963 HORIZONTAL S C A L E I I N C H TO 4 F E E T V E R T I C A L S C A L E I I N C H T 0 2 F E E T •6-23 S E A L E V E L 6.1 FT. o f3 C l QQQCQ <"> p ^7 o -7-20 -8-2 0 • 9- I -9-15 -10-7 11-17 L~' P P 10 20 3 0 40 50 60 70 80 9 0 100 110 120 Figure 24 Vertieal Distribution of the Conspicuous Plants at Qlaoier Point (Areas 5a, 6b, 7), Expressed as Feet Above Tidal Datum Level Feet Above 0 1 2 J A 5 6 7 8 9 1 O Tidal Datum ' 1 ' 1 1 1 ' 1 • ' •— Level Odonthalia floccosa (Esper) Falkenberg SfflrtWlBtygi lonentarla ( Lyngbye ) J . Agardh f . lomentaria  Cladophora trichotoma (C. Agardh) Kutzing Enteromorpha linza (Linnaeus) J . Agardh Phyllospadl* seonlerl Hooker Endocladia muricata (Harvey) J. Agardh Gigartina paplllata (C. Agardh) J . Agardh Prionitis l y a l l i i Harvey Bangia fuscoourpurea (Dillwyn) Lyngbye Fucus evanescens C. Agardh f . evanascens Glolopeltls fureata (Postels and Ruprecht) J. Agardh Heterochordaria abletina (Ruprecht) Setchell and Gardner Rhodomela l a r l a (Turner) C. Agardh Soranthera ulvoldea, Postels and Ruprecht t. ulvoldea  Leathesia dlfformls (Linnaeus) Aresohoug | Porphyra perforata J. Agardh f. perforata  Farlowia mollis (Harvey and Bailey) Parlow and Setchell Monostroma fuscum var. splendens (Rupreoht) Rosenvinge Petalonia debilis (C. Agardh) Derbes and Solier f . debilis  Halosacolon glandlforne (Gmelin) Ruprecht Pterosiphonia bipinnata (Postals and Ruprecht) Falkenberg var. bipinnata Bossiella corymblfera (Uanza) Silva Phaeostrophion irregulare Setchell and Gardner Hedophyllum sessile (C. Agardh) Setchell Ahnfeltla concinna J. Agardh Diva fenestrate Postels and Ruprecht Coral^fla, vancouveriensis Yendo Haploglola andersonii (Farlow) Levrlng Ralfsia funglformls (Qunnerus) Setchell and Gardner Porphyra varlegata (Kjellman) HUB Microcladia borealis Ruprecht Alaria marginata Postels and Ruprecht Spongomorpha coalita (Ruprecht) Collins Collodesme bulllgera Stroemfelt Kereocystls luetkeana (Martens) PostelB and Ruprecht Gymnogongrus linearis (Turn.) J. Agardh Hrmenena flabelllgera (J. Agardh) Kylin Laminaria cuneifolia J. Agardh f. ouneifolla  Plocamium paclflcun Kylin Ptllota f l l i c l n a (Farlow) J. Agardh Corallina officinalis var. ehilensis (Harvey) Kutsing Figure 25 Variation of Sand Levels i n Several Habitats of ?; irregulare , 1963-6L 196LL Month Figure 26 Total Number of Exposures per Month of Various Levels (1-5 f t ) in the Intertidal Zone at Glacier Point, 1963-6I4. 25 - H Day and Night Tides Day Tides N I D I J I F I M I A I M I J I Day and Night Tides Data from Anon. 1962c, 1963. N H) 1 J IF ' M I A 1 M 1 J ' Day Tides Figure 27 Tidal Features of Greatest Exposure Periods During the Night (Winter) at Glacier Point, 196k —I 1 1 1 1 1 1 I I I | I I | I N N November 21 November 22 November 23 December 19 December 20 December 21 Data from Anon. 1963. F i g u r e 28 T i d a l Features of Greatest Exposure Periods During the Day (Spring and Summer) at G l a c i e r P o i n t , 1961). K N N J u l y 9 J u l y 10 J u l y 11 Data from Anon. 1963 Figure 29 Exposure of D i f f e r e n t Levels to A i r Throughout the Year at G l a c i e r P o i n t , 1958-59, Expressed as the Mean Number of Minutes per Each Day of Exposure During the Month © 0.5 f t t ide l e v e l x x 1.0 f t t ide l e v e l x x 1 . 5 f t t ide l e v e l x——x 2.0 f t t ide l e v e l -p g kOO s 300 H 200 H 100 M A M J T 0 T 5.0 f t I+.5 f t o k.o f t 3.5 f t 3.0 f t 2.5 f t "F Month Figure 30 lues of Surface Water Temperatures at Glacier Point. June 1963 to August I96I4. x Maximum surface water temperature in tide pool where P. irregu-lare grows o Surface water temperature j ' J 1 A ' S ' 0 1963 D ' J ' F 1 M 196L Month " H P Figure 31 Values of Surface Water Temperatures at Neah Bay, Washington, U . S . A . , 1931+-1960 Month Data taken from Anon. 1962a Figure 32 Values of Surface Water S a l i n i t y at Glacier Point June 1963 to July 196k j « J I A 1 S 1 0 1 N'D ' J 1 F 'M 'A >M ' J ' J 1 1963 196k Month Pigure 33 Values of Surface Water S a l i n i t y at Neah Bay, Washington, U . S . A . , 193U-1960 Data taken from Anon. 1962a Pigure 3 L Seasonal Values of Soluble Nitrate i n Surface Waters at Glacier Point, 1963-196L x east side • west side 196k Month Figure 35 Seasonal Values of Reactive Phosphorus i n Surface Waters at Glacier Point, 1963-196k x east side • west side \ Pigure 36 Monthly F r e c i p a t i o n at Jordan R i v e r , B. C. i 1 1 1 1 1 1 1 1 l 1 1 J F M A M J J A S O N D Month Fig u r e 37 Monthly A i r Temperatures at Jordan R i v e r , B. C. -1 1 1 1 1 1 1 1 1 1 1 1 J F M A M J J A S O N D Month Data taken from Anon. 1962b Figure 38 V e r t i c a l Distribution of Dominant Plants on Three Adjoining Areas, 6a, 6b and 7 Expressed as Feet Above T i d a l Datum Level Feet Above Tidal Datum Level Area 6a 0 1 2 3 4 5 6 7 8 9 10 11 12 13 H 15 _ J 1 1 i i i i i i i i I i i i . Fucus evanescens C. Agardh f . evanescens  Endocladia muricata (Karvey) J . Agardh Gigartina p a p i l l a t a (C. Agardh)J. Agardh Ahnfeltia coneinna J . Agardh Phaeostrophion irregulare Setchell and Gardner Gymnogongrus l i n e a r i s (Turn.) J . Agardh A l a r i a marginata Postels and Ruprecht Area 6b Bangia fuscoourpurea (Dilluyn) Lyngbye Porphyra perforata J . Agardh f. perforata  Spongomorpha c o a l i t a (Rupreoht) Collins Phaeostrophion irregulare Setchell and Gardner A l a r i a marginata Postels and Ruprecht Corallina vancouveriensis Yendo Area 7 Odonthalia floccosa (Esper) Falkenberg Gigartina p a p i l l a t a (C. Agardh) J . Agardh _ Glolooeltis furcata (Postels and Ruprecht) J . Agardh Fucus evanescens C. Agardh f . evanescens  Endocladia muricata (Harvey) J . Agardh Leathesia dlfformis (Linnaeus) Aresehoug Phvllosoadlit scouleri Hooker Hedophvllum s e s s i l e (C. Agardh) Setchell A l a r i a marginata Postels and Ruprecht Kereocystis luatkeana (Mertens) Postels and Ruprecht Laminaria s e t c h e l l i i S i l v a Figure 39 A l g a l Associations i n Area 6a a . Lower portion of area 6a, before the invasion of sand (May l k , 196k). b. Enlargement of part of a, showing association of perennial red alga A h n f e l t i a concinna and the annual brown alga A l a r i a marginata (May l k , 196k). c„ Dense population of A h n f e l t i a concinna i n area 6a (May l k , 196k). d. Sloping sandy substrate covered mostly with a sand-binding community of Sphacelaria racemosa, and a c o l o n i a l diatom Amphipleura sp., Gymnogongrus l i n e a r i s 9  A l a r i a marginata, and A h n f e l t i a concinna are also v i s i b l e (May l k , 196k). e. Sandy tide pool with buried JP. irregulare and a r t i c u l a t e c o r a l l i n e s (B o s s i e l l a corymbifera and C o r a l l l n a  o f f i c i n a l i s var. chilensis)„ Arrow indicates P. i r r e g u -lare (September k, 196k). Figure kO Appearance of P. irregulare i n Areas 6a, 6b a 0 Typical habit of P_. irregulare i n area 6a ( A p r i l 30, 196k). b„ Portion of same rocks shown i n a with P. irregulare p a r t i a l l y buried i n sand (May 26, 196k). c. Mixture of P. irr e g u l a r e , Spongomorpha coalita,, and* A l a r i a marginata i n area 6b. Arrow indicates P. irregulare ( A p r i l 26, 1963). d. Enlargement of one rock i n c showing blades of P. i r r e g u l a r e . e. Tide pool and non-tide pool populations of P. irregulare i n area 6a. The non-tide pool plants have undergone considerable desiccation ( A p r i l 26, 1963). F i g u r e k l P l a n t s i n A r e a 6 a a . A r e a 6a a f t e r s a n d h a s b e g u n t o come i n a n d v e r y f e w p l a n t s o f P„ i r r e g u l a r e a r e u n c o v e r e d ( J u l y 1 1 , 1 9 6 k ) . B a r n a c l e s a r e s t i l l v i s i b l e a n d t h e a r r o w i n d i c a t e s a f e w r e m n a n t s o f P . i r r e g u l a r e . b 0 A r e a 6 a s h o w i n g p a r t i a l l y b u r i e d A l a r i a m a r g i n a t a a n d G y m n o g o n g r u s l i n e a r i s ( J u l y 1 1 , 1 9 6 k ) . c . B a s a l r e m n a n t s o f P . i r r e g u l a r e i n a r e a 6a. o n h i g h r o c k s w h i c h w e r e n o t b u r i e d ( A u g u s t 1 8 , 1 9 6 k ) . N o t e a b u n d a n c e o f b a r n a c l e s . d . E n l a r g e m e n t o f a s i m i l a r a r e a v i s i b l e i n c , s h o w i n g -l i m p e t s , b a r n a c l e s a n d b a s a l r e m n a n t s o f P . i r r e g u l a r e ( A u g u s t 18, 1 9 6 k ) . e . S e r i e s o f h i g h r o c k s a b o v e t h e b u l k o f s a n d , s h o w i n g P o r p h y r a p e r f o r a t a , F u c u s e v a n e s c e n s 9 b a r n a c l e s a n d m u s s e l s ( A u g u s t 1 8 , 1 9 6 k ) „ A r r o w i n d i c a t e s F u c u s e v a n ° e s c e n s . Figure k2 A l g a l Associa t ions i n Sandy Areas at G l a c i e r Point a. Area of extreme sand cover (7-8 months per year) where very few perennial algae can s u r v i v e . Several annuals are present during the period of sand subsidence (Enteromorpha l i n z a , Porphyra var iegata , Monostroma  fuscum). Arrow indicates a few specimens of A h n f e l t i a  concinna and G i g a r t i n a p a p i l l a t a ( A p r i l 30, 196k). b. T y p i c a l habitat of Gymnogongrus l i n e a r i s on rocks p a r t i a l l y buried i n sand. This i s from area #k (June 26, 196k). c. Habit of Gymnogongrus l i n e a r i s and G i g a r t i n a p a p i l l a t a i n area 6a ( A p r i l 30, 196k). d» G i g a r t i n a p a p i l l a t a near area #5 ( A p r i l 30, 196k). e. Enlargement of G i g a r t i n a p a p i l l a t a from d ( A p r i l 30, 196k). Figure k3 Sand Fluctuation i n a Location to the North of Area 6a and Associated Vegetation a. Sand leve l s on May l k , 196k showing encroachment of sand plants. b. Sand levels on June 26, 196k showing burying of plants. Arrows i n a,b indicate the same rock on May l k , 196k and June 26, 196k. c. D i s t r i b u t i o n of sand and plant communities i n the loc a t i o n to the north of area 6a (May l k , 196k). Note the conspicuous ripples on the sand. d. Perennial Gigartina p a p i l l a t a populations at about 6.5 f t . i n the lo c a t i o n to the north of area 6a (May Ii i , 196k). e. P. irregulare at about 2.0 f t . i n the l o c a t i o n to the north of area 6a (May l k , 196k). F i g u r e k k H a b i t a t o f A r e a 7 a n d A s s o c i a t e d P l a n t s a . A r e a 7 i n l a t e s u m m e r ( A u g u s t 1 9 , 1 9 6 k ) s h o w i n g t h e c o m p l e t e a b s e n c e o f s a n d . b . L o w e r i n t e r t i d a l r e g i o n o f a r e a 7> s h o w i n g a b u n d a n c e o f H e d o p h y l l u m s e s s i l e . C a l l i t h a m n i o n p i k e a n u m i s g r o w i n g o n t h e m u s s e l s a n d b a r n a c l e s ( A u g u s t 1 9 , 1 9 6 k ) . c . L o w e r i n t e r t i d a l r e g i o n o f a r e a 7, s h o w i n g a b u n d a n c e o f P h y l l o s p a d i x s c o u l e r i , H e d o p h y l l u m s e s s i l e , L a m i n a r i a  s e t c h e l l i i , a n d v a r i o u s o t h e r a l g a e ( A u g u s t 1 9 , 1 9 6 1 ± ) . d . U p p e r i n t e r t i d a l r e g i o n o f s a m e a r e a s h o w i n g a s s o c i a t i o n o f F u c u s e v a n e s c e n s s O d o n t h a l i a f l o c c o s a , a n d L e a t h e s i a  d i f f o r m i s ( A u g u s t 1 9 , 1 9 6 k ) . Pigure k5>. Growth of Plants of P_. irregulare at Glacier Point, Expressed as Grams Fresh Weight of Blades/ra 2 D 1 J I~~F 1 M 1 A ' M Month Pigure k7 Growth of Plants of P_. i r regulare at G l a c i e r P o i n t , Expressed as Grains Fresh Weight of Blades/m 2 11 D 1 J 1 F 1 M 1 A 1 M r _ J Month NTP = non t ide pool TP = t ide pool F i g u r e L8 5o -25-0 -25 -0 25 -o -25 0 _ 25 -0 25 0 25 0 25 0 G r o w t h o f T i d e P o o l P l a n t s o f P . i r r e g u l a r e i n A r e a 6 a , E x p r e s s e d as P e r c e n t O c c u r r e n c e o f D i f f e r e n t S i z e C l a s s e s , 1963-61+ 1 1961+ I I I . 6-26 5-26 5-11+ '+-30 • • • 1+-16 2-26 1-25 12-1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 85 80 75 70 65 60 55 50 1+5 1+0 35 30 2$ 20 15 10 5 0 B l a d e L e n g t h (mm) Pigure k 9 Grovrth of Tide Pool Plants of P. i r r e g u l a r e i n Area 5 , Expressed as Percent Occurrence of D i f f e r e n t Size Classes , 1 9 6 2 - 6 3 25 0 25 0 2$ 0 25 0 • g 0 S o V . 25 o-5o • 25' 0 50-0 12-29 l i I I I I I I I I I I I I I 1 80 75 70 65 60 55 50 US U-0 35 30 25 20 15 10 5 o Blade Length (mm) Figure 50 Growth of Non-Tide Pool Plants of P. i r regu lare in Area 6 a , Expressed as the Percent Occurrence of Di f ferent Size Classes , 1963-6)1 5 0 1 — 196k 2 5 -0-"25-0 25 0 -2 5 -0 25 0-J 2 5 -0 -25-0-5 0 -25 0-1 196k . . I I I 6-26 5-27 . . I I k-30 k-16 2 5 " • I l l I I 2-26 1-25 12-1 I I 1 1 1 1 1 1 1 1 1 1 1 1 75 70 65 60 55 5o k5 ko 35 30 25 20 15 10 5 o Blade Length (mm) R e c e i v e d w i t h o u t F i g u r e 51 . F i l m e d as r e c e i v e d . U n i v e r s i t y M i c r o f i l m s , I n c . Figure 52 Growth of P. irregulare at Glacier Point, Expressed as the Mean Blade Length, 1963-6k koJ • p TP area 6a, k f t 1963-6k 3 0 H 2 0 J 1 0 j NTP area 6a, 2.5 f t , 1963-6k ^NTP area 6a, 3.8 f t , 1963-6k D J F M A M 196k NTP = non tide pool TP = tide pool Figure 5 3 Growth of P. i r regulare at Glac ier P o i n t , Expressed as the Mean Blade Length, 1 9 6 3 - 6 k area 6 a , 1 9 6 3 - 6 k j I F I M 1 A 1 M~~ 1 J 1 Month NTP = non-t ide pool TP = t ide pool 60-% of t o t a l k0-20" Figure Sk-Variation of Blade Length of P. irregulare at Different V e r t i c a l Heights mean length = 50.18 mm width = 25.88 mm 60-20 ko % of t o t a l kO-20-60 1 80 1 100 mean length = 2$.k9 mm width = 13.23 ram T~1 1 1 r 80 length (mm) high tide pool at k.5' f t 20 kO 60 length (mm) at 3.6 f t 60-of t o t a l kO-20-mean length = 25.28 mm width = 111. 72 ram n — 1 — I — 1 — r 20 kO 60 80 length (mm) at 3.36 f t 60-raean length = 28.72 mm width = 16.66 mm % of t o t a l k0-20-60-% of t o t a l k0-20-1—1 1 1 mean length = 2k.76 mm width = 12.1i2 mm 20 kO 60 80 length (mm) at 3.0k f t n r n 1 20 kO 60 80 length (mm) at 2.5 f t 60-% of t o t a l k0-20-raean length = 30.63 ram width - 11.65 mm - 1 — I — I — r 20 kO 60 80 length (mm) at 2.16 f t Figure 55 Variation of Blade Length at Different V e r t i c a l Heights on a Sloping Substratum 60H % of t o t a l 20 H mean length width 10.31 3.87 % of t o t a l 6oH 1+0-20H 20 1+0 60 "i ' i l 80 mean length = 13.92 width = 5.52 % of t o t a l 20 ' 1+0 ' 6b ' 80 length (mm) at 3.0-2.75 f t length (mm) at 2.75-2.5 60-| of t o t a l 1+0-1 20 H mean length = 22.91+ width = 8.62 of t o t a l 60 H 1+0 20 . • i „ i — r — i — i — i 20 1+0 60 80 length (mm) at 2.25-2.0 f t mean length = 3l+. 76 width = 11.77 20 —F—I—F=l 1+0 60 80 60 A koA 20 H mean length = 18.55 width = 7.19 - 1— i — i — i 1—i—i 20 1+0 60 80 length (mm) at 2.$^2.25 f t length (mm) at 2.0-1.75 f t Figure 56 Blade Morphology of Mature Plants of P. irregulare""' a. Type specimen of P, i r r e g u l a r e c o l l e c t e d at B o l i n a s , C a l i f o r n i a . b 0 Young Blades of P. i r regulare c o l l e c t e d from Squaw Is land, Cape Arago, Oregon. c. Type specimen of P. australe from Point Conception (Government P o i n t ) , C a l i f o r n i a . d. Isotype of P. australe from Point Conception. e. P. i r r e g u l a r e c o l l e c t e d at Point Conception, by P . C . S i l v a on June 13, 191+9 (#5516). f . Blade morphology of P, i r r e g u l a r e on s l o p i n g sub-stratum at G l a c i e r P o i n t , 1. 3 f t . 2. 2.75 f t . 3. 2.5 f t . L L . 2.25 f t . 5 . 2 f t . 6. 1.75 f t . A l l specimens c o l l e c t e d May 25 , 1963. The largest mature blades i n each sample are shown. Figures a-f are same s c a l e , x 1/3. Figure 57 ' Reproductive Cycle of P_. i r regulare During 1963, and Percent of Various Reproductive Organs 100 -, 60 -t>9 ~ 60 hO-20 -2-26 3-20 k-26 ' 5-25 ' 6-8 '6-25 Date of C o l l e c t i o n 7 - 7 8-21-::-p l u r i l o c u l a r '—-J sporangia • u n i l o c u l a r sporangia both -"-Materials were dug-out from under sand. Figure 58 V a r i a t i o n of Monthly Hours of Br ight Sun at Jordan River - l 1 1 1 1 1 1 1 n 1 1 r J F M A M J J A S 0 N D Month Data taken from Anon. 1962b. Pigure 60 Spectra l Energy D i s t r i b u t i o n Curve of Cool-White Lamps Taken from Sylvania Engineering B u l l e t i n , 0-205. Figure 61 Response Curve of Phototube c of Photovolt E l e c t r o n i c Photometer 3000 kOOO 5000 6000 Wave Length (A) Figure 62 Growth of Germlings from Unispores in Different S a l i n i t i e s A f t e r 25 Days 60 -, 0 5 10 15 20 25 30 35 h o L5 50 55 60 65 70 75 S a l i n i t y % 0 Figure 63 Growth of Germlings from Plurispores i n Different S a l i n i t i e s A fter 10 and 35 Days 0 5 io 15 20 25 30 35 ko kS 5o 55 60 65 70 S a l i n i t y % e Figure 6k Growth of Germlings from Plurispores i n Different S a l i n i t i e s , After 10 and 35 Days lOO-i 35 days old 20 22 2k 26 28 36 32 3k 36 38 kO k2 hk k6 k8 5b S a l i n i t y %„ • p C <D 60-, Figure 65 Growth of Germlings from Unispores in Different S a l i n i t i e s , After 20 Days Figure 66 Growth of Germlings from Plurispores at Different Temperatures ( S a l i n i t y 31.It %«} 1 1 r 0 10 20 30 Days Old Figure 6? Growth of Germlings from Unispores at Different Temperatures ( S a l i n i t y 31.1+%.) T r 0 10 20 30 Days Old Figure 68 Growth of Germlings from Unispores i n Various S a l i n i t i e s and Temperatures, After 30 Days 160-1 11+0-120-100-80-60-1+0-20-5 w p H i 11+0-120-100-80-60-i+oH 20-H 15 20 25 30 S a l i n i t y % e Figure 69 35 1+0 Growth of Germlings from Plurispores i n Various S a l i n i t i e s and Temperatures, A f t e r 30 Days 1 5 20 1 1 1~" 25 30 S a l i n i t y % 35 1+0 cn p d C t $ Survival of Maximum ro o -F" o o o CO o o o ro o ro vn o Oo vn M ro a w CD fD 3 P c t o 3 P a co e < < P I—1 o "-4 p M H * CD 3 4 H» 3 C t (—1 •=<! ±11 CQ 0 ca H * 3 a CD CD 3 c t cn P H H -3 H -e t CD M . , ro o o a — ai ,-0 O vn O vn ro o ro vn o vn -p-vn vn o vn vn o o o vn o Germination of Maximum ro o o l _ o CO o o o _ J l _ *3 c i CD -0 o Q CD 3 H» 3 P c t o 3 O >-!> 3 H * ca " d O CD CO H -3 a CD CD 3 c t Co P c t CD o o o Figure 72 Growth of Unispores i n Natural Seawater I80-. with Additions of Nitrate, A f t e r 20 Days 160-lkO-120-100-80-60-kO-20-0 2.5 7.5 12.5 17.5 Additions of Nitrate (^ig-at/1) 12.k 17.k 22.k 27.k Actual Nitrate (ug-at/1) Figure 73 Growth of Unispores in Natural Seawater with Additions of Phosphate, After 20 Days 2CH T T .'25 ' .'75 ' l'.o ' i . 5 o Additions of Phosphate (jug-at/1) 1.65 2.15 2.65 3.15 Actual Phosphate (^ig-at/1) Figure 71+ Growth of Germlings from Unispores and Plurispores Under D i f f e r e n t Light I n t e n s i t i e s , A f t e r 25 Days Foot-Candles of I l l u m i n a t i o n Figure 75 Apparent Photosynthesis of the Blades and Holdfasts of P. i r regulare at D i f f e r e n t Light I n t e n s i t i e s and 11.5°C blades — I 1 1 r — 700 1000 1 1 r~ 100 kOO 1200 Light Intensi ty i n Foot-Candles Pigure 76 Rate of Apparent Photosynthesis of the Blades and Holdfasts of P. i r regulare at D i f f e r e n t Temperatures Temperature °C Pigure 77 Rate of R e s p i r a t i o n of the Blades and Holdfasts of P. i r regulare at D i f f e r e n t Temperatures c •H 5 7 9 11 13 15 17 19 21 Temperature °C Figure 78 Rate of Apparent Photosynthesis of Blades of P. i r regulare at D i f f e r e n t S a l i n i t i e s and 11.5°C i r 20 21+ 28 S a l i n i t y %, 32 36 1+0 Figure 79 Rate of Respira t ion of Blades of P. i r r e g u l a r e at D i f f e r e n t S a l i n i t i e s and 11.5°C 20 21+ 28 32 36 1+0 S a l i n i t y 0 / o Pigure 80 Rate of Apparent Photosynthesis of Blades of P. i r r e g u l a r e i n D i f f e r e n t Supplements of Phosphate •H •P OJ o 3 1 2 H 1 H i n i t i a l nutr ients KO POi 3 5i.o 2.15 o H 1 1 1 1 1 1 1 1 r i o .25 .75 1.25 1.75 "* Phosphate Supplements (ug-at/1) Pigure 81 Rate of Apparent Photosynthesis of Blades of P. i r r e g u l a r e i n D i f f e r e n t Supplements of Ni t ra te •H c S-i to OJ OJ o rH 6 J 5 3 J 2 H i n i t i a l nutr ients NO- P0 • = (1) x = (2) k 31 if.15 7.0 2 . 0 3 o 9 o 2.5 7.5 12.5 17.5 Nitra te Supplements (ug-at/1) Figure 82 Temperature Tolerance of Common Plants at Glacier Point Temperature °C l 10 , 20 | 25 i 30 i 32 i . 35 i 36 i 37 i 33 , 39 . 40 , V. , 42 , A3  Banela fuscoonrpurea (Dlllwyn) Iyngbye Fucus evanescens C. Agardh f . evanescens  Civnnogongrus linearis (Turn.) J . Agardh Phaeostrophlon Irregulare Setchell and Gardner Hvelophvcus lntestinale Saunders Gigartina papillata (C. Agardh) J . Agardh Prionitis l y a l l i i Harvey Farlowia mollis (Harvey and Bailey) Farlow and Setchell Petalonia deb/lls (C. Agardh) Derbes and Solier f. debilis Odonthalia floccosa (Esper) Falkenberg Leathesla dlfformla (Linnaeus) Areschoug Pvlalella lltoraH,p ( Linnaeus ) Kjoilman '  Scvtoslphon lomentaria ( Lyngbye ) J. Agardh f. lonentarla  Soranthera ulvoidea Postels and Ruprecht f . ulvoidea  Ptilota f i l ic ina (Farlow) J . Agardh Heterochordarla abietina (Ruprecht) Setchell and Gardner Scvtoslphon bullosus Saunders . Dllsea californlca (J. Agardh) 0. Kiintze Monostroma fuscum var. splendens (Ruprecht) Roaenvlnge Alaria marginata Postels and Ruprecht laminaria cunelfolla J . Agardh f. cuneifolla Plocamium paclflcum Kylin Spongomorpha solnescens Kutzing Haplogloia andersonii (Farlow) Lavrlng Collodesme bulllgera Stroemfelt Pigure 83 Germination of Plurispores After Exposure to Various Temperatures 100 -1 1 1 1 1 1 80 -60- I k O - I 20 -15- 20- 25 26 27 28 29 30 31 32 33 3k 35 Temperature °C Pigure 8k Temperature Tolerance of Blades of ?. irregulare at Various S a l i n i t i e s S a l i n i t y %o Pigure 85 Temperature Tolerance of the Macroscopic Plants of p. i r regulare to a Sudden Immersion i n a High Temperature i H > • H > CO 100 , 75-50-25 -100 -, 75 50-] 25-100 75 5o-25-100 -r 75 50 25-1 I mi III 1111 black = dead white = a l i v e 5 min 10 min I 15 min 20 min 22°0 28°C 3h°C 38°C 39°C L0°C Pigure 86 S a l i n i t y Tolerance of the Macroscopic Plants of P_. i r r e g u l a r e A f t e r D i f f e r e n t Periods of Time. Length of Bar Indicates L i v i n g Plants 1 -5 -o •rj 10 -\ CO U 1 15 A m 20 -cd ° l " " " 1 " ! "i •'" " " ^ " 1 j i " ' i " " , 1 1 1 ( 1 '"' *" '| i 1 ,' 0 10 20 30 kO 50 60 70 80 90 100 S a l i n i t y % oo Salinity Tolerance of Several of the Fucus evanescens 0. Agardh f. evanescens  Hvelophvcua lnteatlnale Saunders Glolopeltla furcata (Poatela and Ruprecht) J. Agardh Gigartina papillata (0. Agardh) J. Agardh Odonthalia floccosa (Espar) Falkenberg Bangla fnscopurpurea (Dillwyn) Lyngbye Prlonltla l y a l l i i Harvey Porphyra perforata J. Agardh f. perforata Endocladla murlcata (Harvey) J. Agardh Irldophycus heterocarpum (Postels and Ruprecht) S. and Q. SvmnogongruB llnearla (Turn.) J. Agardh Collodeame bulllgera Stroemfelt Soranthera ulvoidea Postels and Ruprecht f, ulvoidea  Rhodomela larix (Turner) C. Agardh Microcladia borealis Ruprecht Farlowia mollis (Harvey and Bailey) Farlow and Setchell Phaeostrophlon Irregulare Setchell and Gardner Scvtoslphon bullosus Saunders SSrtffPiphon lomentarla ( Iyngbye ) J . Agardh f. lomentarla Petalonia debilis (C. Agardh) Derbes and Solier f. debilis Leatheala dlfformls (Linnaeus) Areschoug Pvlalella l l t o r a l l a ( Llnnaeua ) KJellman Enteromorpha linza (Linnaeus) J. Agardh Errthrophvllum deleaaerloldes J. Agardh Heterochordarla abletlna (Ruprecht) Setchell and Gardner Dllsea callfornlca (J. Agardh) 0. Kuntze Halosacolon glandiforme (Gmelin) Ruprecht Ptilota f l l l o l n a (Farlow) J. Agardh Haplogloia anderaonll (Farlow) Levrlng Laminaria cuneifolia J . Agardh f. cnnelfolla Plocamium paclflcum Kylin Leaaonlopals l l t t o r a l l s (Farlow and Setchell) Reinke Spongomorpha coalita (Rupreoht) Collins Figure 87 Conspiouous Plants at Glacier Point After 2U Hours Salinity % 0 0 10 20 30 kO 50 60 70 80 90 100 110 120 I 1 L 1 I I I I I I I I i I Figure 88 Average Water Loss of Complete Macroscopic Plants of P, irregulare at Different Temperatures in the Laboratory 1 1 1 1 n 30 60 90 120 150 Exposure (Min) • high tide plants (IN5 f t ) o low tide plants (2.0 f t ) Figure 89 Average Water Loss of Blades and Holdfasts of P. i r regulare at 20°C in the Laboratory i i I 1 1 1 1 10 20 30 kO 50 60 70 Exposure (Min) Figure 90 Average Water Loss of Complete Macroscopic Plants of _P. i r regulare i n Nature 100 80 • p • & •H CD •H -P •H o 60 -k o -20 -shade (5-lk-6k) cloudy (k-30-6k; l 1 1 1 1 1 1 1 1 1 30 60 90 120 150 180 210 2k0 2?0 300 Exposure (Min) 100 Figure 91 L e t h a l i t y of the Blades of JP. i r regulare versus Water Loss •I injured i—i uninjured 0 20 kO 60 80 100 of I n i t i a l Weight Figure 92 Temperature and S a l i n i t y Near Populations of P. irregulare on the P a c i f i c Coast of North America 28 29 30 S a l i n i t y 31 32 33 3k _L_ Data taken from Anon. 1959, 1962a N ^.Massacre Bay , Alaska ( Attu I. ) , 1958 

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