CLASSIFICATION OF THE BACTERIA. 87 
related to them, — the Leptothrix, Beggiatoa, and 
Crenothrix. 
1. Fil. with indistinct articulations 
Fil. very slender, short. . . . BACILLUS, 
Fil. very slender, long . . . . LEPTOTHRIX. 
Wal thick, broad.) 2°. 5 ot, BEGGIRTOM 
2. Fil. articulated distinctly . . . . CRENOTHRIX. 
g@. Bacillus, Cohn. 
The bacilli are characterized by slender fila- 
ments, straight, short or of moderate length, 
rigid or flexible, endowed or not with motion. 
One species is chromogene, the B. ruber of 
Cohn. Finally it is to this genus that we should 
refer the Amylobacter of Trécul. 
B. subtilis, Cohn (Vibrio subtilis, Ehrb.; Ferment 
butyrique, Pasteur). 
Filaments very slender and elongated, formed of a 
single cell having usually a length of 6 yw, or of two 
articles of which the total length is then 12 y, or of 
three (length 16 yw), or of a greater number (some- 
times as many as twenty, with a total length of 40 to 
60 and 130 ~); thickness not measurable, well-defined 
movements of flexion, active or passive, and of trans- 
lation forward or backward; reproduction by fission 
and by globular or oval spores developing themselves 
in the interior of the articles (Cohn). Is found in 
stagnant water. 
Plays a great réle in the butyric fermentation 
(Pasteur). This B. exists in rennet, can support 
a temperature of 105°, and live in a medium 
deprived of free oxygen, in which case it takes 
a form céphalée, containing persistent spores, 
