126 



Mastitis. 



It has not yet been possible to demonstrate this bacillus in 

 mixed milk, since there occur too many bacteria of similar mor- 

 phology in stable manure, in the air, and under the epithelia of the 

 teats. 



At any rate the milk must be considered as spoiled when it 

 contains secretion from udders with pyogenic infections, and should 

 be excluded from the market, since its injurious effects upon health 

 seem to have been demonstrated in the sense of the pure food act. 



Infections with bacteria of the coli-typhus group frequently 

 occur when the cows are kept in filthy condition, with unclean bed- 

 ding, and also when manipulations are undertaken by milkers in 

 order to dilate the milk ducts (penetration with straws, quills, and 



CHiltures of Bacillus paratyphus. 1 X 800. (After Kitt.) 



contaminated milking tubes). Representatives of this group of 

 organisms were described by Jensen and Streit, Guillebeau, Kitt, 

 Freudenreich, Lucet, Sven Wall and Weicliel, as the cause of high- 

 ly acute forms of mastitis. The bacteria are short rods with round- 

 ed ends, mostly motile; they do not take Gram's stain. Accord- 

 ing to their biologic characteristics various varieties may be dis- 

 tinguished, which at times approach more closely to the colon 

 group, at other times more to the aerogenes group, and at times even 

 to the enteritidis group, which cause meat poisoning. 



Milk becomes coagulated with gas formation. The acidification and coagulation 

 occur earlier with some varieties than with others. The colon group always ferments 

 galactose, glucose, laevulose, mannose, lactose, maltose, arabinose, rhamnose, xylose, 

 mannit and sorbit, frequently also sorbose, saccharose, raffinose and dulzit, but not 



