THE FERN'S PLACE IN NATURE. 57 



fering from the algae in possessing no chlorophyll, and in the 

 higher forms in the loss of sexual methods of reproduction.* 

 Three classes are distinguished : 



(a) Phycomycetes (algal fungi). 



(b) Ascomycetes (spore-sac-fungi lichens).f 



(c} Bastdiomycetes (mushrooms, puff-balls, rusts). 



1 33. The BRYOPHYTES include forms whose plant-body 

 varies from a thallus to a distinct leafy axis containing only a 

 rudimentary fibro-vascular system, if any; their life-history in- 

 volves two alternating phases: (i) A highly organized sexual 

 phase producing antherids and archegones (Gametophyte); and 

 (2) A spore-producing phase living parasitically on the first 

 and forming spores asexually. Four groups are prominently 

 marked : 



1. Hepaticce (liverworts). J 



2. Anthocerotes (horned liverworts).}: 



3. Sphagna (peat mosses). 



4. Musci (true mosses) . 



1 34. The PTERIDOPHYTES have a well-developed fibro- 

 vascular system with highly differentiated tissues distributed 

 through a leafy axis. Their life-history involves two phases: 

 (i) A thalloid phase (prothallus) producing antherids and arche- 

 gones ]| (gametophyte) ; and (2) A highly developed asexual 



* For an elementary work on the systematic study of the fungi the student 

 can use "Moulds, Mildews, and Mushrooms" by the present writer (Henry 

 Holt & Co.). 



t The lichens are mostly ascomycetous fungi parasitic on algse. Tucker- 

 man : North American Lichens, is the best systematic work, but difficult for 

 students. 



I The Hepaticae of the Eastern States have been treated by the present 

 writer in Gray's Manual of Botany, 6th ed. Those of the Pacific coast have 

 been elaborately described and illustrated by Hoiue : The Hepaticas and An- 

 thocerotes of California, Mem. Torrey Club, vol. 7. 



The mosses of North America are treated in synoptical form in Barnes : 

 Artificial Keys to the Genera and Species of Mosses (1897). This should be 

 supplemented by the descriptions in Lesquereux and James : Manual of the 

 Mosses of North America (1884). 



| From this common character the Bryophytes and Pteridophytes are some 

 times classed together as Archegoniates. 



