22 PATHOGENIC BACTERIA 



stage of growth, in order that abnormal, degenerate forms might 

 be eliminated. The precise mode of preparation, the age of the 

 culture, and, when important, its original source, are given un- 

 der the several figures. 



The fungi, which are pathogenic in the human subject, be- 

 long to the botanical subdivision of (1) Schizomycetes (^zVctf, 

 I split, KvHrjS, a fungus) Fission-fungi, or Bacteria; (2) Blas- 

 tomycetes (BXaffroZ, a bud) Budding-fungi, or yeasts; (3) Hy- 

 phomycetes ("TpoZ, a web), Hyphal-fungi, or moulds. 



Strictly speaking, the study of bacteriology does not com- 

 prise that of yeasts and moulds, which are for this reason ex- 

 cluded from some systematic works devoted to bacteriology. 

 Much less could the consideration of animal micro -parasites find 

 a place in a strict system of bacteriology, although, owing to its 

 present small dimensions, this subject is included, and conven- 

 iently so, in at least one standard English work on " Bacter- 

 iology." 



With the exception of thrush, all the illustrations given are 

 limited to bacteria proper or schizomycetes. 



In regard to this classification of pathogenic fungi,* it will 

 be enough to say that bacteria are achlorophyllous vegetable or- 

 ganisms, characterized by a fissiparous method of reproduction, 

 though in a certain number there occurs a second or additional 

 method, viz., spore-formation. 



Yeasts, whilst again they may multiply by spore-formation, 

 do so as an ordinary method by budding, i.e.) in place of the 

 cell becoming symmetrically partitioned into two or more ele- 



* The absence of chlorophyll, which has commonly served as a basis for defining 

 the group of fungi, is not held by Sachs as sufficiently fundamental for such a sub- 

 division; he classes with achlorophyllous schizomycetes certain chlorophyllous 

 forms which multiply by a similar method, under the name of schizophyta, etc. 



