70 T O R R E Y A 



made to biological classification. Phylogeny soon became the fundamental basis 

 for classificatory endeavor. So far as the fungi are concerned we should not 

 overlook the influence of the work of Hofmeister in 1851 on the bryophytes 

 and pteridophytes. The recognition of an alternation of generations in these 

 groups had its effect on studies of the algae and fungi. 



Every student who has taken a course in general botany is familiar with 

 the system of classification which places the algae and fungi together in the 

 division Thallophyta. We have no thought of attempting to reach any con- 

 clusions about this broad question of the taxonomic disposition of the fungi. 

 Whether the fungi are to be regarded as one of two subdivisions of the Thallo- 

 phyta, the algae being the other, depends upon the origin of the fungi. We say 

 this in spite of a recent assertion that the taxonomist "is not interested in the 

 origin, but in the character of his plants." On the origin of the fungi, G. M. 

 Smith, in his "Cryptogamic Botany," Vol. I, "Algae and Fungi" (1938) 

 writes, "This is highly controversial and opinion is divided as to whether 

 they arose from the protozoa or whether they had either a monophyletic or 

 polyphyletic origin among the algae. If they arose from protozoa, they should 

 be put in one or more divisions coordinate in rank with the various algal 

 divisions ; if they arose from the algae, they should be placed as classes of one 

 or more of the algal divisions." 



Smith reviews the algal and the protozoan theories of the origin of the 

 fungi and concludes that "it seems more probable that the fungi evolved from 

 protozoa rather than from algae." He bases his conclusion largely on metabolism 

 and the type of flagellation in the Phycomycetes. There are some algal groups 

 in which there occur chlorophyll-less forms which are so similar morpho- 

 logically that they cannot be regarded as distinct from the green forms. It is 

 pointed out that these saprophytic and parasitic algae accumulate reserve 

 carbohydrates as starch just as do the green algae. In contrast the Phycomy- 

 cetes are reported generally . to accumulate carbohydrates as glycogen but 

 never as starch. The zoospores and gametes of the green algae are never uni- 

 flagellate whereas the motile cells of certain Phycomycetes are regularly uni- 

 flagellate. It is admitted that the question of the origin of the Ascomycetes is a 

 more difficult one. The similarity in the sex organs, and the structures developed 

 subsequent to fertilization, in the Ascomycetes and in the red algae are strik- 

 ing and have caused many workers to assume a relationship between these 

 groups. Smith argues that these distinctive reproductive structures may have 

 evolved along independent phyletic lines. He thinks the Ascomycetes had 

 their origin in the Phycomycetes and that the Basidiom^cetes arose b}- modi- 

 fication from the Ascomycetes. In his classification he rejects the Thallophyta 

 as a division of the plant kingdom and in its place substitutes nine divisions, 

 of which the Myxothallophyta, or slime molds, constitute one and the 



