CLASSIFICATION OF BACTERIA IN FAMILIES. 55 



2. Genus: Bacillus (Colin, Migula). Shorter or 



longer rod forms, sometimes short ovoid 

 cells, and in other species long thread forms. 

 Motile, with flagella distributed over the 

 entire body. Endospore formation occurs 

 in many species. 



3. Genus: Pseudomonas. Shorter or longer 



cylindrical cells, sometimes thread forms, 

 motile, with polar flagella. The number of 

 flagella varies in different species from one 

 to ten. Endospore formation is present in 

 a few of the species. 

 3. Family : Spirallficece. 



Cells more or less curved, at times forming dis- 

 tinct spirals when a number are joined end to 

 end. Division of the cells in one direction of 

 space, that is, at right angles to the long axis 

 of the rod. Endospore formation is absent 

 except in a few species. Motility is usually 

 present; where the motile organs are known 

 they are polar. 



1. Genus: Spirosoma (Migula). Cells usually 



twisted in rather large spirals, non-motile, 

 without flagella, stiff without flexibility. 

 The number of species of this genus is very 

 small. 



2. Genus : Microspira (Schroter). Cells mostly 



comma-form or sausage shaped, curved or 

 joined in S-shaped figures, or even in long 

 spiral chains. Motile, with one to three 

 polar flagella. Endospore formation has 

 not been demonstrated. 



3. Genus: Spirillum (Ehrenberg). Twisted rods 



