THE FISSION FUNGI. 155 



IV. THE FISSION FUNGI, SCHIZOMYCETES. 



Under the fission fungi or bacteria* is included a 

 large group of minute, unicellular, spherical, or thread- 

 like organisms, which multiply by fission. As they are 

 ordinarily devoid of chlorophyll, they are, like the fungi, 

 compelled to lead a parasitic or saprophytic existence. 

 Multiplication and assimilation of nutriment usually 

 occur with such energy that intense alteration and 

 destruction of the nutritive substratum is the result of 

 their development ; they are often able to increase this 

 decomposition still more by setting up fermentation, 

 and in the cases where they lead a parasitic existence 

 they are wont to bring disease and death to their host. 



1. General Morphological Characters. 



The fission fungi exhibit great varieties in external General 

 form. Some grow as spheres or oval cells ; this form o 

 growth is termed micrococcus ; if the spheres form 



Fig. 3lA. Various vegetative forms X 700. 



a, micrococcus, isolated. b, in the act of subdivision (diplococcus.) 

 c, streptococcus, torula. d, zooglaea. 



chaplet-like chains the organism is termed streptococcus 

 or torula; if arranged in irregular masses it is dis- 



* De Bary prefers the term Bacteria because some varieties contain 

 chlorophyll, and are thus not true " fungi." The term " Bacterium" 

 was formerly employed for a division of the fission fungi; as, however, 

 this division can no longer be maintained, there is no objection to 

 de Bary's suggestion. Other names for this class are: Microbes, 

 Champignons, Torulacees, Bacteries (Pasteur); Mikrozymas(Bechamp) ; 

 Spalthefe (Niigeli) ; Mikrosporinen, and Monadinen (Klebs) ; Cocco- 

 bacteria with the subdivisions Mikro- Meso- Meg-acoccus, Mikro- 

 Meso- Mega-bacteria Gliacoccus, Petalococcus, &c. (Billroth). 



