DEVELOPMENT OE THE BACTERIA. 133 



quently we cannot invoke the movements of the 

 liquid in order to explain their division. The 

 bacteria of charbon, then, take but little oxygen 

 from the tissues : they do not vegetate luxuriantly 

 in the organism; and certainly, if we judge by a 

 calculation necessarily approximative, their devel- 

 opment is seven or eight times less rapid than in 

 the strongly oxygenated serum of culture experi- 

 ments (Toussaint). 



Polymorphism. — The spores of which we have 

 traced the genesis constitute those germs of which 

 the origin has for a long time been misunder- 

 stood, — those permanent spores or durable spores 

 (Dauersporen), thus called because of their re- 

 markable degree of resistance to temperature, 

 desiccation, and all the agents which kill adult 

 bacteria or arrest their development. 



These " organs " are disseminated in great num- 

 bers in various media under the form of little 

 rounded corpuscles absolutely similar to the micro- 

 cocci from which it is absolutely impossible to 

 differentiate them. It is, indeed, very probable 

 that the greater part, if not all of these organisms, 

 are the spores of filiform bacteria. 



In the impossibility of recognizing these forms 

 so nearly related, of referring them to such or 

 such a determined organism, the attempt has been 

 made to cultivate them, in order to follow their 

 development. We have just seen the results of 

 this cultivation for the Bacillus ; but, in the hands 

 of the greater number of experimenters, the re- 



