Journal of Applied Microscopy. 



207 



milk was found, in general, to introduce 

 a sufficient numbei* of bacteria for con- 

 venient study upon a plate culture made 

 In 15 CO. of media. For a time both gela- 

 tin and agar plate cultures were made, 

 but the use of the former was discon- 

 tinued, as agar was found to be more 



The milk of each of the four teats of a 

 cow was examined on two successive 

 days, and after a lapse of two weeks, 

 some of them were examined upon four 

 more days. Four or possibly five species 

 were observed, only one being common 

 to the four teats. Although the bacterial 



A photograph of a section through the teat and one quarter of the udder of a cow. The parts rep- 

 resented by the letters A, B, C indicate the three arbitrary divisions into which 

 the gland was divided for purposes of examination. 



satisfactory. The total number of colo- 

 nies did not appear until after several 

 days in the incubator at a temperature of 

 37.5 degrees C. The plates were then 

 examined and sub-cultures were 

 made from^the colonies of the apparently 

 different species. The various forms of 

 colonies were carefully described and the 

 number of each recorded. 



flora of each of the teats diflEered from 

 that of its neighbors, the same species 

 were found to persist in the same teat 

 from day to day. They were not present 

 in the same relative numbers on each 

 occasion. 



The milk of another cow was examined 

 on five occasions, covering a period of 

 eight months. In the milk of this animal 



