64 STORRS AGRICULTURAL EXPERIMENT STATION. 



hours, as will be seen by the first column in Table 27, there was 

 no increase of bacteria. The next twelve hours showed consid- 

 erable increase. There was, however, a slight change in the 

 variety of bacteria which appear in the succe.ssive analyses. 



2. A slight increase in the number of B. acidi ladici may 

 be noticed in the first forty hours, and a considerable increase 

 in the last twelve hours. 



3. The Streptococcus group remained practically unchanged 

 in numbers during the first forty hours, but increased during 

 the last twelve. 



4. The most peculiar characteristic of this sample of milk 

 was the high numbers of Sarcina I. In the fresh milk 62 per 

 cetit. of the bacteria were of this species, and for the first forty 

 hours the number remained nearly constant, there being a 

 slight falling off both in total numbers and in percentage. 

 In the last twelve hours, when the lactic organisms and the 

 Streptococcus increased in numbers, the Sarchia dropped off 

 markedly, and in the last test were few in numbers. 



5. It will be noticed that this sample shows a very high 

 percentage of No. 220. This is a lactic organism closely re- 

 lated to B. acidi lactici, and having many of the characteristics 

 of that more common species, but differing from it very sharply 

 in its characteristic colony. It will be seen that in this sample 

 of milk this lactic organism developed, in both numbers and 

 percentage, during the forty hours when the other species w^ere 

 practically constant, but that in the last twelve hours it in- 

 creased in numbers parallel \\ith the increase in the number 

 of other lactic organisms. 



6. The chief difference between this sample at 13° and the 

 one given in Table 25 is in the total failure of most bacteria 

 to grow for forty hours, in the failure of the Streptococcus to 

 develop until the last twelve hours, and in the great numbers 

 of Sarcina. 



Expcrimeyit No. 12. January 28. — This experiment, which 

 w^as an exact repetition of the last, four days later, was suc- 

 cessful throughout, and the results given in the following 

 tables are quite reliable. 



SAMPLE KEPT AT 20 DEGREES. 



The study of the results with milk kept at 20°, given in 

 Tables 29 and 30, shows nothing especially different from the 



