328 Manual of Veterinary Microbiology. 



supplied a milk very rich in streptococci; that from 

 the cow quickly showed an acid reaction and became 

 clotted; the udder finally became inflamed. Inocu- 

 lation in the mamma of a nursing bitch remained 

 without etiect; the dog, cat, rabbit, and guinea pig 

 were also unaffected by intra-venous and intra peri- 

 toneal inoculations. 



Etiology. — The disease is communicated through 

 the intermediation of those who have charge of the 

 milking of the cows, their hands being soiled with 

 the diseased milk. When the latter is mixed with 

 good milk this also takes the same characters. Con- 

 tagion to the cows must, therefore, be prevented by 

 disinfection of the hands, and contagion to the nor- 

 mal milk by keeping the milk from the diseased cows 

 in separate vessels. Such milk is, moreover, unfit for 

 human consumption. 



Besides this disease, remarkable on account of its 

 extreme contagiousness, the udder of the cow is sub- 

 ject to various microbic lesions. M. Lucet especially 

 called attention to infectious forms of mammitis due 

 to an external cause; in a series of cases of acute 

 mammitis he found one or several germs; these were 

 sometimes micrococci, sometimes bacilli, and some- 

 times both together. Penetration of the germs most 

 frequently occurs through solutions of continuity of 

 the integument of the udder. The microbe being 

 different in different cases, we can readily under- 

 stand that the severity of the disease will be very 

 variable. 



Among the number of infectious forms of mam- 

 mitis with internal cause tubercular mammitis should 

 be especially mentioned. 



