DEVELOPMENT OF THE BACTERIA. 115 



above all the hydrates of carbon and their deriv- 

 atives ; and in this respect they resemble animals." 



Absorption. — How are these various substances 

 absorbed ? The observations of Grimm, Hoffmann, 

 de Seynes, etc., permit us to assure ourselves that 

 these organisms absorb by endosmosis the sub- 

 stances upon which they are nourished. 



Grimm, upon examining with the microscope 

 some particles of lemon containing bacteria and 

 spores of algse, saw a certain number of the former 

 gather aro\md a spore, and fix themselves to it 

 by one of their extremities. They did not pene- 

 trate it ; but when they abandoned it, the spore 

 had diminished in volume, and lost a portion of its 

 contents, while the bacteria had taken a greenish 

 color. 



Hoffmann has seen that these little organisms, 

 when placed in a solution of carmine or of fu- 

 schine, after a time are colored an intense red, 

 while the mucus surrounding them remains color- 

 less. 



De Seynes, also, from his observations upon 

 the vibrios which accompanied some colored fila- 

 ments of Penicillium glaucum, believes that bacte- 

 ria are susceptible of absorbing coloring matters 

 from vegetables and from animals with which they 

 are in contact. 



Oxygen. — The role of oxygen in the life of the 

 bacteria has given rise to numerous controversies. 

 First, it seems a priori that the bacteria ought 



