90 Dairy Bacteriology. 



these foods are consumed by the individual in smaller 

 amounts than is generally the case where milk is used, and 

 also to a greater extent by adults, lessens still further the 

 danger of infection. 



Notwithstanding this, numerous observers ' especially in 

 Germany have succeeded in finding the tubercle bacillus in 

 market butter, but this fact is not so surprising when it is 

 remembered that a very large fraction of their cattle show 

 the presence of the disease as indicated by the tuberculin 

 test, a condition that does not obtain in any large section 

 in this country. 



These observations on the presence of the tubercle bacil- 

 lus in butter have been questioned somewhat of late 2 by 

 the determination of the fact that butter may contain an 

 organism that possesses the property of being stained in 

 the same way as the tubercle organism. Differentiation 

 between the two forms is rendered more difficult by the 

 fact that this tubercle-like organism is also capable of pro- 

 ducing in animals lesions that simulate those of tubercu- 

 losis, although a careful examination reveals definite differ- 

 ences. Petri 1 has recently determined that both the true 

 tubercle and the acid-resisting butter organism may be 

 readily found in market butter. 



In the various milk products it has been experimentally 

 determined that the true tubercle bacillus is able to retain 

 its vitality in butter for a number of months and in cheese 

 for nearly a year. 



Treatment of milk from tuberculous cows. While it has 

 been shown that it is practically impossible to foretell 

 whether the milk of any reacting animal actually contains 



Obermiiller, Hyg. Rund , 1897, p. 712; Petri, Arb. a. d. Kais. Ges. Amte, 1898, 

 14: 1; Hermann und Morgenrotb, Hyg. Rund., 1898, p. 217. 

 Rabinowitsch. Zelt. f. Hyg., 1897, 26: 90. 



