The American Naturalist. 



THE CONSTANCY OF BACTERIAL SPECIES IN 

 NORMAL FORE MILK. 1 



By H. L. Bolley. 



It is recognized that aside from actual dirt, as, for example, 

 drippings from the hands of the milker, dirt from his clothing, 

 and hairs and manurial particles from the sides of the animal, 

 that the fore milk constitutes the most productive source of the 

 bacterial flora of milk. Schultz and others have placed quan- 

 titative determinations at from fifty to one hundred thousand 

 per cubic centimeter. As the character of the germ content is 

 becoming such a matter of importance in economic labors 

 with milk and its product, it is apparent that a consideration 

 of the types of germ present in the normal udder should com- 

 mand early attention of the bacteriologically inclined dairy- 

 men. 



The question is of necessity, one of such breadth that it 

 must be approached in separate phases, such, as for example, 

 the study of the presence ftr absence of physiological groups, 

 constancy of definite species, etc. During the year just closed 

 two such points have been under investigation. The primary 

 object, while being a matter of simple interest, had also the 

 direct aim of determining the relation of normal fore milk to 

 curd inflation in cheese manufactory. The results of the 

 work have in part been reported in a paper read before the 

 General Section of the American Association of Agricultural 

 Colleges and Experimental Stations, July 19, 1895 ; showing 

 that, in so far as the investigation had been carried, gas gen- 

 erating species such as are accountable for " pinhole forma- 

 tion " or curd inflation are not normal to the fore milk of the 

 healthy udder. 2 



1 Read before the Section of Botany of the American Association for the Ad- 

 vancement of Science, Springfield Meeting, August 31, 1895. Also published in 

 Centralblatt fur Bacteriologie und Parasitenkunde, Ah. II, B and I, JSTo. 22-23. 



2 Bolley and Hall : Cheese curd inflation : Its relation to the bacterial flora of 

 fore milk. Centralb. f. Bact. u. Parasiteuk., II, Ab. I, Bd., No. 22-23. 



