CONTENTS 



PAGE 



GLOSSARY. . ., .. . ... . .... . . xix 



ERRATA . . . . . . . . ; xx n 



INTRODUCTION '. . . - . . . xx jjj 



CHAPTER I 

 HISTORY OF LICHENOLOGY 



A. INTRODUCTORY . . . . . . . z 



B. PERIOD I. PREVIOUS TO 1694 ... 2 



C. PERIOD II. 16941729 ..... 5 



D. PERIOD III. 1729 1780 ... .6 



E. PERIOD IV. 17801803 ... ' 9 



F. PERIOD V. 1803 1846 t 10 



G. PERIOD VI. 18461867 . . 15 

 H. PERIOD VII. 1867 AND AFTER . . . . . 18 



CHAPTER II 

 CONSTITUENTS OF THE LICHEN THALLUS 



I. LICHEN GONIDIA 

 i. GONIDIA IN RELATION TO THE THALLUS 



A. HISTORICAL ACCOUNT OF LICHEN GONIDIA . . 21 



B. GONIDIA CONTRASTED WITH ALGAE .... 22 



C. CULTURE EXPERIMENTS WITH THE LICHEN THALLUS 24 



D. THEORIES AS TO THE ORIGIN OF GONIDIA . 25 



E. MICROGONIDIA . . . . . . . 26 



F. COMPOSITE NATURE OF THALLUS . . . . . 27 



G. SYNTHETIC CULTURES 27 



H. HYMENIAL GONIDIA 30 



I. NATURE OF ASSOCIATION BETWEEN ALGA AND 



FUNGUS 31 



a. Consortium and symbiosis 



b. Different forms of association 



J. RECENT VIEWS ON SYMBIOSIS AND PARASITISM . 36 



2. PHYSIOLOGY OF THE SYMBIONTS 



A. NUTRITION OF LICHEN ALGAE. -. . , .;* \ 39 



a. Character of algal cells 



b. Supply of nitrogen 



c. Effect on the alga 



d. Supply of carbon 



e. Nutrition within the symbiotic plant 



f. Affinities of lichen gonidia 



B. NUTRITION OF LICHEN FUNGI 44 



C. SYMBIOSIS OF OTHER PLANTS . 45 



