CHAPTER IT. 



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 role 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 



