Microhic Diseases Individually Considered. 195 



toms become aggravated with the progressive evolu- 

 tion of the local lesion and the subject succumbs in 

 thirty-six to forty-eight hours. When the disease has 

 been somewhat prolonged, other tumors with the 

 same characters not infrequently supervene. The dis- 

 tribution of these secondary tumors is not in relation 

 with that of the lymphatics ; their development ap- 

 pears to take place through the intermediation of the 

 blood. 



At the autopsy the local lesion is the predominant 

 feature, the invaded muscles are friable and more or 

 less darkened in color (charbou); their fibrous bundles 

 are readily dissociated ; the fibers retain their striation 

 but their contents is broken up into hyaline, vitreous 

 blocks (hyaline degeneration). The intra-muscular 

 connective tissue, as well as that which surrounds the 

 muscular masses, is thickened and infiltrated with a 

 yellowish serosity ; this cedema sometimes assumes con- 

 siderable proportions. The formation of gas, inherent 

 to the life of the germ, causes the detachment of the 

 tissues, a true localized emphysema in the central part 

 of the tumor. The gases produced are, chiefly, car- 

 bonic acid and marsh gas. 



The lymphatic glands in relation to the tumor are 

 reddened, ecchymosed and infiltrated. 



After death the bodies very rapidly putrefy. 



The animals which spontaneously contract the dis- 

 ease are cattle, sheep and goats. The receptivity of 

 the first is not the same at all ages ; calves of less than 

 six months do not contract the natural disease, and 

 cattle of over four or five years also seem to escape. 



Microbe. — The pathogenic agents in this disease are 

 straight rods, isolated or occasionally associated in pairs, 



