168 Plant Biology 



(het-ero -trof ik) (Gr. heteros, other; trophe, nourishment or food). 

 Heterotrophic fungi may be (1) saprophytes (sap'rofite) (Gr. sapros^ 

 dead; phyton, plant), living on dead organic materials, or (2) parasites 

 (pa' ra site) (Gr. para, beside; sitos^ food), living in or on the body of 

 another living plant or animal. A few species are autotrophic and will 

 be considered later. 



Fungi lack true leaves, stems, and roots; they do not form multicellular 

 embryos; they lack the two vascular tissues (phloem and xylem) which 

 are present in the higher plants. The fungi group includes the bacteria 

 (Phylum Schizomycophyta) , the slime molds (Phylum Myxomycophyta) , 

 and the true (higher) fungi (Phylum Eumycophyta) , representatives of 

 which will be considered in this chapter. The true fungi and slime molds 

 differ from the bacteria in that the bacteria are unicellular, do not have 

 an organized nucleus, and usually have smaller cells and their methods of 

 reproduction differ from those of the slime molds and true fungi. 



BACTERIA (PHYLUM SCHIZOMYCOPHYTA) 



Bacteria (bak-te'ria) (Gr. bakterion, small rod) are placed in the 

 phylum Schizomycophyta (skiz o my -kof i ta) (Gr. Schizo, fission; myco, 

 fungus; phyta, plants) (Fig. 34). Bacteria are simple, unicellular plants 

 without chlorophyll; thus a majority of them are unable to photosyn- 

 thesize their foods but must secure them in other ways. The method of 

 nutrition for a majority of them is heterotrophic (het ero -trof ik) (Gr. 

 heteros, other; trophe, food or nourish), securing their foods from out- 

 side sources. Consequently, they may be (1) saprophytes (sap'rofite) 

 (Gr. sapros, dead; phyton, plant), which obtain foods from nonliving, 

 organic materials or (2) parasites (pa' ra site) (Gr. para, beside; sitos, 

 food), which live in or on the bodies of living plants or animals. In the 

 latter case, if a diseased condition is produced, they are known as patho- 

 genic bacteria (path o -jen' ik) (Gr. pathos, suffering; genos, produce). 



A small minority of bacteria are autotrophic (ot o -trof ik) (Gr. autos, 

 self; trophe, nourish), being able to synthesize organic foods from carbon 

 dioxide and other simple inorganic substances. These autotrophic species 

 may be grouped into (1) chemosynthetic, in which the energy required 

 for the synthesis of foods is derived from the oxidation of certain chemi- 

 cals, and (2) photosynthetic, in which light supplies the food-producing 

 energy and the photosynthetic pigments are reddish-purple or greenish 

 (not chlorophyll) . 



Some of the chemosynthetic bacteria include: (1) the sulfur bacteria 

 which live in waters, soils, and sewage, and which oxidize hydrogen sul- 



