378 BACTERIOLOGY. 



relation to oxygen, and they are also without disease- 

 producing properties. 



Morphology. It is a slender rod with rounded ends. 

 It may appear as single rods, or, in cultures, as long 

 threads. It is motile, though not actively so. The 



Fig. 81. 



'55 



If 



-*< If 



Tetanus bacillus, a. Vegetative stage, from gelatin culture, u. Spore 

 stage, showing pin shapes. 



motility is somewhat increased by observing the organ- 

 ism upon a warm stage. 



At the temperature of the body it rapidly forms 

 spores. These are round, thicker than the cell, and 

 usually occupy one of its poles, giving to the rod 

 the appearance of a small pin. (Fig. 81.) When in 

 the spore stage it is not motile. 



It is stained by the ordinary aniline staining re- 

 agents. It remains colored under the employment of 

 Gram's method. 



Cultural peculiarities. It is an exquisite anaerobe 

 and cannot be brought to development under the access 

 of oxygen. It grows well in an atmosphere of pure 

 hydrogen, but does not grow under the influence of 

 carbonic acid. 



It grows in ordinary nutrient gelatin and agar-agar 

 of a slightly alkaline reaction. Gelatin is slowly lique- 

 fied, with the coincident production of a small amount 



