INFECTION". 



81 



The absence of chlorophyl distinguishes them from the algae, and 

 places them among the fungi ; a view which is supported by nearly 

 all the best botanists of our day. The generally accepted classifica- 

 tion is at present that of Cohn, and is — 



1. Spherobacteria, or globular bacteria. 



2. Micro or rdd bacteria. 



3. Desmo or filamentous bacteria. 



4. Spiro or spiral bacteria. 



In 1874 Billroth, the noted surgeon and author on surgical pa- 

 thology, published a large work upon disease-germs — viz., upon 

 coccobacteria septica — and arrived at very different conclusions from 

 those of Cohn, which have not, however, gained any general accept- 

 ance. Billroth claims that there is but one single original species 

 of bacteria, and that all others are derived from it, viz., coccobacteria 

 septica. This vegetable organism may present itself in two forms : 

 the globular coccus, and that of rods, bacteria. These two forms 

 may reproduce by elongation and transverse division, or may pass 

 from one to the other. 



According to the variation in size, Billroth speaks of micrococcus, 

 micro-bacteria ; mesococcus, mesobacteria ; megacoccus, megabacte- 

 ria. And, according to their relations to one another, as mono- 

 coccus, monobacteria ; diplococcus (in pairs), diplobacteria ; strepto- 

 coccus (in chains), streptobacteria ; gliococcus, gliobacteria ; petalo- 

 coccus (foot or base), petalobacteria. 



We have said that the most generally accepted classification was 

 that of Cohn, but, before considering it more particularly, we feel 

 obliged to notice that of another noted German author, which is 

 based upon the action of these germs. 



!Nageli speaks — 



1. Of mucorini, or mold-fungi. 



2. Saccharomycetes, or budding fungi, which produce the fer- 

 inentation of wine, beer, yeast, etc. 



3. Schizomycetes, or fission-fungi, which produce putrefactive 

 processes. This group embraces the micrococci and bacteria. 



I. Spherobacteria. — Spherical bacteria are defined by their 

 name. They are round or oval bodies of very small size. They are 

 sometimes found isolated, often appearing in pairs — diplococcus ; or 

 again we meet with them in the form of chains, or articulations — 

 streptococcus ; or united together by a sort of homogeneous material 

 — zoogleaform. "When in this condition they are young and in pro- 

 cess of active proliferation. Sometimes they form a coating upon 

 the surface of liquids. When we speak of a mycoderma, they have 



6 



