BACILLUS CHAUVEI 559 
inciting agent was first obtained in artificial cultural media by Arloing, 
(^ornevin and Thomas.' 
Morphology. — B. chauvei is a rod-shaped bacillus, measuring from 
().() to 1 micron in diameter and from 2 to 5 microns in length. The 
organisms typically exliibit rounded ends, and they occur commonly 
either singly or in pairs. They practically never form chains, even 
upon the surface of parenchymatous organs; differing, therefore, in this 
respect from the Bacillus of malignant edema (Vibrion septique). The 
organisms at the height of their development are quite actively motile, 
and when stained with proper stains they exhibit many peritrichic 
flagella. Capsules ha\e not been demonstrated. 
Spores form in media rich in protein. The spores are usually situated 
somewhat nearer one end of the parent cell, although they may be 
central; they are somewhat greater in diameter than the vegetative 
rod, and relatively long in proportion to their width. These long-oval 
spores are unusual among anaerobic bacteria. 
Fig. 75. — Bacillus chauvei, spore formation. X 1000. 
The organisms, when young and growing vigorously, are Gram- 
positive but they lose the ability to retain the Gram stain within a 
comparatively short time. Also, involution forms which stain irregu- 
larly are produced in the presence of serum or tissue fluids. 
Isolation and Culture.— Bacillus chauvei is an exquisite anaerobe; its 
requirements in this respect are very exacting. It grows with diffi- 
culty upon ordinary artificial media, and even in a protein-rich environ- 
ment, development is rarely luxuriant. The initial growth outside the 
animal body is difficult to obtain. Albuminous media, as blood serum 
or blood agar, are better adapted for its isolation than any others. 
Growth in media containing sterile tissue, especially for the first 
cultivation, is better than media containing altered protein. The 
■organism may be obtained from the heart blood, the peritoneal exudate, 
• Le Charbon S.\mptoinatique du Boeuf. Paris, 1887. 
