FUNGI, ftinit (Lat., mushrooms; connected with Gk. aohyor, sphongos, eirhyos, spongos, sponge). A group of non-chlorophyll-bearing plants. They constitute the second division of the thallophytes (the lowest primary division of plants), and because they lack ,the green color ing matter, chlorophyll, or pigments related to chlorophyll, they are forced to live as parasites on living plants and animals, or as saprophytes on dead organisms or their products. As stated under ALGJE, the fungi are believed to have been derived from that group, and to have arisen at different times from several stocks; in other words, the fungi constitute a polyphyletic group. Consequently, the fungi do not present a continuous series of related forms. On the con trary, there are at least two lines (Schizomycetes, Myxomycetes) which have little resemblance either to one another or to the great body of higher fungi, except through a general similarity of physiological processes. Indeed, in some clas
sifications the name fungi is restricted to the higher forms, whose bodies are usually made up of filaments. It seems probable, however, that the terms fungi and algae will be given a more general application, as a matter of convenience, and cease to have special significance in classi fication.
The fungi include five large classes: Bacteria (Schizomycetes), slime-molds (Myxomycetes), alga-like fungi (Phycomycetes), sac-fungi (As comyeetes), and toadstools and their allies (Basidiomycetes). A sixth class, the yeasts (Saccharomycetes), is much smaller than the others. The habits and some of the striking pe culiarities of these groups are discussed in spe cial articles under the above names. This article considers points of morphology with especial bearing on classification, and includes an account of certain biological principles.