BACILLUS OF TETANUS. 397 



but they will usually be found to differ from it in their 

 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. 85. 



Jl* 



2* -v 



' B* 



Tetanus bacillus. A. Vegetative stage, from gelatin culture. B. Spore 

 stage, showing pin shapes. 



motility is rendered somewhat more conspicuous by 

 examining the organism 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. 85.) When in the 

 spore stage it is not motile. 



It is stained by the ordinary aniline staining reagents. 

 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 

 18 



