86 MODERX DAIRY PRACTICE. 



stirring during the milking that the bacterial content 

 would be about even in the whole of the can. But control 

 experiments showed in a very striking manner that the 

 number of bacteria was largest on the surface of the milk. 

 All samples taken from the depth of the mess of milk, by 

 means of sterilized, so-called Pasteur pipettes showed 

 very few bacteria, on an average 20.3 per cc., while all 

 samples taken from the surface contained over 200 per 

 cc. If I should venture an explanation of this phenomenon, 

 I would say that it still more confirms the observations 

 made in the preceding, that one of the main sources of the 

 infection of the milk is the lower part of the stomach and 

 the udder region of the cow, from which filthiness with ac- 

 companying bacteria all the time is falling down during 

 the milking. 



Milk from stables where winter conditions have entered 

 has usually shown a higher bacteria content. Bacteriologi- 

 cal analyses of such milk half an hour after the close of 

 the milking have given the following data for the content 

 per cubic centimeter: 4100; 2450; 1890; 14,670; 830; 

 3030; 5450; 21,700; and 1030. 



I have made bacteriological analyses of several samples 

 of milk supplied to creameries, the samples being taken 

 under different conditions. The results naturally differed 

 greatly. Milk from a well-conducted farm was examined 

 after standing for one hour in the warm stable and then 

 hauled to the creamery near by. The milk contained on 

 an average 4500 bacteria per cubic centimeter. Milk 

 from a filthy stable where the cows were standing in 

 manure, on a warm day, transported by rail to the city 

 where I took the sample, seven hours after the milking, con- 

 tained 25,000 bacteria per cc. After having been kept 



