286 



STATE BOARD OF AGRICULTURE. 



of the methods employed : Cow No. 2, showing the organisms present 

 in the left front quarter ; No. 3, in the left rear quarter ; No. 4=, in right 

 front, left rear and left front quarter; No. 5 in the right rear quarter; 

 No. 7 in the left rear quarter. 



The number of colonies appearing upon the surface of the media varied 

 with the samples examined. Only one or two colonies would develop 

 from the sample examined from one cow, while from another, the 

 surface of the media would show hundreds of colonies. Very few 

 other organisms present in the milk grew on this medium. Gram nega- 

 tive organisms will occassionally make their appearance and very 

 often be the predominating organism on the surface of the media. 

 These may be, in most part, eliminated by using aseptic methods in 

 the handling of the samples of milk. 



This method has also been emploj^ed with success in isolating Bad. 

 abortus from the stomach content of aborted fetuses, from the fetal 

 membranes and from the uterine exudate of cows which have aborted. 



TABLE II.-THE COMPARATIVE RESULTS OF THE TWO METHODS FOR STUDYING THE PRESENCE OF 



BACT. ABORTUS IN MILK. 



The — sign indicates negative findings by guinea pig inoculation or by direct cultural method (gentian violet agar plate). 

 The + sign indicates the presence of Bad. abortus in the spleen and liver of inoculated guinea pigs or by direct cultural 

 method. 



G. v., refers to gentian violet agar plate. 



