THE MORPHOLOGY OF BACTERIA 



5 



tococcus mcsentcrioidcs, the capsules become enormously swollen 

 by the imbibition of water. The capsules of adjacent individuals 

 also coalesce, forming a common gelatinous envelope surround- 

 ing a number of individuals, as in A and D, Fig. 2. When 

 these individuals are arranged in chains we have forms, as 



Fig. 3. Showing false branching. 



A. in Cladothrix dichotoma after Fischer. B. a fungus filament. C. Mycobact. tuberculosis 

 after A. Coppen Jones. D. Mycobact. influenza after Grassberger. E. bacteroid bodies 

 of leguminous root tubercles after Beijerinck. F. an infecting filament of the latter 

 after Atkinson. 



in B, C, and G, of the same figure. In certain of the higher bac- 

 teria, as in Cladothrix dichotoma, Fig. 3, A, we have chains of in- 

 dividuals surrounded by a capsule, which at first sight is identical 

 with that in Bad. Pastcurianum, Fig. 2, G, but in Cladothrix the 

 capsule is firmer and of the nature of a membrane or sheath. 



C. The Flagella 

 Certain genera of bacteria are provided with hairlike processes 

 known as flagella. They are simply filamentous extensions of 

 the capsule, and proceed from the latter and not from the central 

 body. They vary in thickness from extremely delicate hairs, 

 scarcely discernible with the highest powers of the microscope, 



