82 MORPHOLOGY OF THE BACTERIA. 



Cells cylindrical, straight, rarely a little twisted, 

 larger than the cells of B. termo, isolated or united 

 in pairs, sometimes in fours, never more ; length 

 3.8 to 5.25 /a, thickness attains 1.25 /j, ; movements 

 like those of B. termo, but a little more active. 



Is found in various vegetable and animal in- 

 fusions of fresh or salt water, often takes the 

 form of zooglcea containing motionless rods in 

 their mucus substance. Warming has met it 

 in the form of chains composed of eight to ten 

 cells (torula). Its protoplasm is dotted with re- 

 fractive granules. 



It is not known whether B. lineola constitutes 

 a specific ferment (Cohn). 



The B. fusiform, Warming, differs from the preceding by 

 the form of its body, which is attenuated at the two extrem- 

 ities ; length 2 to 5 ft, width 0.5 to 0.8 ^ ; plasma not punc- 

 tated. 



Beside these species, which have been well 

 studied, may be placed the following, which 

 demand new investigations : — 



B. punctum, Ehrb. 



Elongated rods, oval, colorless, having slow 

 movements, oscillating, often united in pairs; 

 length 5.2 /a, thickness 1.7 /a. Diverse infusions 

 of animal substances. 



B. catenula, Duj. 



Body filiform, cylindrical, often united in 

 three, four, or five ; length 3 to 4 /x,, thickness 

 0.4 to 0.5 /jl. In fetid infusions, in typhoid fe- 

 ver (Coze and Feltz). 



