CONTENTS 



PAGE 



Glossary . . . xix 



Errata xxii 



Introduction xxiii 



CHAPTER I 

 HISTORY OF LICHENOLOGY 



A. Introductory . . i 



B. Period I. Previous to 1694 . . .2 



C. Period II. 1694— 1729 ... . 5 



D. Period III. 1729— 1780 ... , . 6 



E. Period IV. 1780 — 1803 . . -9 



F. Period V. 1803 — 1846 . .10 



G. Period VI. 1846— 1867 . . . , 15 

 H. Period VII. 1867 and after . ... 18 



CHAPTER n 



CONSTITUENTS OF THE LICHEN THALLUS 



I. LICHEN GONIDIA 



I. GONIDIA IN RELATION TO THE THALLUS 



A. Historical account of Lichen Gonidia . . 21 



B. (^ONIDIA contrasted WITH ALGAE .... 22 



C. GultureExperimentswiththeLichenThallus 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 



S 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 Lich£n Fungi 44 



C. Symbiosis of other Plants . . . . 45 



