CHAPTER II. 
CLASSIFICATION OF THE BACTERIA. 
§ 1.— PosITION OF THE BACTERIA. 
THE place of the bacteria in the scale of beings, 
for a long time undetermined, demands to be 
established with precision; not only for the natu- 
ralists, who only view the question from a system- 
atic point of view, but above all for the biologists 
who study the réle of these organisms in the chem- 
ical or pathological phenomena with which they 
are associated. According to Ch. Robin, not to 
define the animal or vegetable nature of these 
organisms, ‘is for them as grave as it would be for 
a chemist to leave undecided the question as to 
whether it was nitrogen or hydrogen, urea or 
stearine, which he had obtained from a tissue, or of 
which he is following the combinations in certain 
operations.” 
This determination is, to-day, possible ; and, if 
there are still some differences of opinion among 
naturalists as to the place of the bacteria among 
the cryptogams, there is but one opinion as to 
their vegetable nature. 
It is surprising to see a savant like M. Pasteur 
“not to pronounce positively upon the vegetable 
