58 STORRS AGRICULTURAL EXPERIMENT STATION. 
2. The lactic bacteria, Group I., began to increase a little 
later than Group IV., and rose to about 560,000,000 in 144 
hours, at which time they constituted 60 per cent. of the whole. 
3. Group III. began to increase about the same time, and 
continued to multiply till tMe close, increasing in percentage as 
well as in actual numbers. 
4. The liquefying bacteria developed more than usual, and 
remained at about 30,000,000 during the last day or so. 
5. The tables also show that at this temperature, as in other 
cases, there was a very general development of all species of 
bacteria present in the original milk, the only one to disappear 
totally being Group V. Allothers increased with considerable 
regularity through the whole experiment. 
Milk kept at 20°.—1. ‘The development of Group I. began 
very rapidly about the 2oth hour, and rose with exceptional 
rapidity, until at 48 hours there were over 2,000,000,000 in 
each cubic centimeter; and if to these be added Group II., there 
were about 2,500,000,000 of lactic bacteria present before 
curdling took place. 
2. Group III. developed slightly and was present at the 
end in considerable numbers, though in small percentage. 
3. Group IV. continued to increase in numbers with de- 
creasing percentage till curdling. : 
4. All other bacteria were largely excluded from the milk 
by the development of the lactic species. 
5. ‘The most striking phenomenon was the number of lactic 
bacteria that developed before curdling took place. The 10° 
milk contained 560,000,000 when it curdled, while the 20° milk 
contained five times as many. ‘To what is due this difference 
in numbers present at the curdling period we are not yet con- 
vinced. It may be that in this particular case the large num- . 
bers of Group IV., which develop a slight alkaline reaction, 
may have counteracted the acid. produced by Groups I., II., 
and III., and thus delayed the curdling. 
