146 



TETANUS, MALIGNANT (EDEMA, ETC. 



It is found a. in wounds in cases of tetanus, b. as a sapro- 

 phyte in the soil, especially manured soil of gardens and 

 stables, and c. in the intestinal secretions of animals. 



Morphology. The bacillus of tetanus as obtained in cult- 

 ures is seen in one of two forms, either in the vegetative form 

 or as a spore -bearing bacterium. 



Its vegetative form is a short rod with round ends, occur- 

 ring singly or in pairs, or sometimes forming long filaments. 



FIG. 60. 



Bacillus tetani : A, vegetative stage ; B, spore-stage, showing pin-shapes. (Abbott.) 



Its spore-bearing form is quite characteristic, resembling a 

 pin ; this is due to the fact that the spore is formed at one 

 end of the bacillus, and as the bacillus bulges at that portion 

 the typical appearance of a pin is given to the bacillus 

 (Fig. '60). _ 



The Bacillus tetani stains with all the anilin dyes, and also 

 by Gram's method. 



Biologic Characters. The Bacillus tetani is purely an- 

 aerobic, not developing at all in the presence of oxygen. It 

 grows in all culture-media at a temperature as low as 18 or 



