34 STORRS AGRICULTURAL EXPERIMENT STATION. 



An examination of the tables of this experiment given on 

 the preceding page shows the following facts: 



1. During the first six hours there was no appreciable 

 change in either number or variety of bacteria. 



2. The numbers of B. acidi ladici showed a constant in- 

 crease in the successive tests. The number, however, did not 

 become so high as in the first experiment, and the percentage 

 at the end of twentj^-four hours was only 25, the actual num- 

 ber being also very small. 



3. The presence of B. acidi ladici II. was not observed in 

 any of the tests. 



4. B. aerogenes was abundant in this sample of milk. It 

 was not observed in the plate made from fresh milk, but a few 

 colonies were found in the milk at the age of six hours. From 

 that point they continued to increase until the end, when they 

 reached the number of 100,000 and a percentage of 16.3. This, 

 it should be remarked here, is a very high percentage for this 

 species of bacterium, as may be seen by comparing Table 4 with 

 the other tables on the following pages. 



5. The Streptococcals was quite abundant throughout the 

 whole series of tests, but while increasing constantly in num- 

 bers showed no appreciable change in percentage. The test 

 made at nineteen hours indicated a dropping off in the number 

 of the Streptococcus colonies, probably due to an imperfect dif- 

 ferentiation between this species and B. acidi lactici, which 

 sometimes resemble each other. 



6. The two species of Sarcina were present in all tests and 

 slowly increased in numbers. One species remained through- 

 out with a practicall)' constant percentage, while the other 

 species fell off from a high proportion of about 17.9 per cent, 

 down to about 2.5 and then disappeared. 



7. In this sample liqucficrs were also very abundant. Thej^ 

 increased with unusual rapidity during the first nineteen hours; 

 afterwards they declined with equal rapidity, and in the last 

 test only about 10 per cent, were found. There was, however, 

 a constant increase in total number of liquefiers. 



