Invasion of the Udder by Bacteria. 



297 



TABLE No. XI. 



Summary of Kesults of the Examination of Gelatin Plate 

 Cultures of Udders 12, 13, 14, 15. 



Group IV. — An examination of udders Nos. 16 to 19 inclusive 

 is being made just as this publication goes to press. The results 

 cannot be discussed in detail at present. A bacillus is found quite 

 generally distributed in the fore milk and the four udders. This 

 bacillus agrees with the micrococci, heretofore obtained, in its long- 

 deferred action upon milk. At 37.5° C, after five days the casein of 

 milk is precipitated with an alkaline reaction. The coagulum is sub- 

 sequently digested. 



The Structure of the Udder. 



A study of the relations of the milk channels and reservoirs of 

 the udder tends to strengthen the conclusions that the udder may 

 be normally invaded by bacteria. Figure 58 shows a plaster of 

 Paris cast of the lower portion of one-quarter of an udder. The 

 duct of the teat and the milk cistern (galactif erous sinus), are plainly 

 shown. The plaster penetrated the fine lactiferous ducts of the 

 udder, but owing to the fragile nature of the cast it was impossible 

 to dissect away the tough tissue without ruining the model. 



