BACTERIA AS PLANTS. 29 



arise from a membrane surrounding the bacterium, 

 but have an intimate connection with the proto- 



FlG. 15. Bacteria provided with flagella : a, Single flagellum ; b, 

 Two flagella; c, A tuft of flagella at one end; d, Tufts of 

 flagella at both ends ; e, Uniform covering of flagella ; f, 

 Showing the origin of flagella from the outer layer of the body. 



plasmic content. Their distribution is different 

 in different species of bacteria. Some species 



