44 STORKS AGRICULTURAL EXPERIMENT STATION. 



Experbnents Nos. 6 and 7. January. — The two present 

 experiments were performed in the month of January at a 

 time when the cows were kept in the barn and, therefore, 

 under conditions quite different from those of the previous 

 experiments. These two experiments are especially striking 

 as showing the extraordinary variation in results which are 

 obtained under conditions that are apparently identical. The 

 two experiments were performed within two days of each 

 other, one upon January 15, and the other upon January 17. 

 In both cases the milk was obtained from the same cow, at 

 the same stable, and the samples were treated in identically 

 the same manner. The results, however, were for quite inex- 

 plicable reasons very unlike. The four tables on pages 42 

 and 43 give the results of these two experiments. 



In considering the results given in the above tables we 

 notice first the great differences between those for the two 

 samples which were, so far as we could determine, obtained 

 and kept under identical conditions. The differences will be 

 seen in the following points: 



In the first sample the number of bacteria rose in twenty-six 

 hours to 2,000,000; in the second sample they increased in 

 twenty-seven hours to 43,000,000. This difference seems to 

 be totally unexplained by the conditions of the experiment. 



A second point of difference was the number of the common 

 B. acidi ladici. In the first experiment they were not found 

 in the fresh milk or milk six hours old, although it is probable 

 that some of the undetermined bacteria were of this species. 

 The number arose onl}" to 16 per cent, at the last test, at 

 twenty-six hours. In the second experiment the number of 

 this species at the outset was 18 per cent, and it constantly 

 increased until at the last test it was nearly 80 per cent. 

 These differences are partly explained by the large percentage 

 of^ undetermined species in the first experiment, but even if all 

 of the undetermined bacteria w^ere placed in the column of acid 

 organisms it would still leave a surprising difference between 

 these two samples of milk as regards the development of this 

 particular species. 



A third great difference is in the number of the Streptococcus 

 group which in the first experiment was very high and in the 

 last experiment, especially in the later tests, exceptionally low, 



