COMPARISON OF BACTERIA IN MILK. a 
8. At the time of curdling, it will be seen, the percentage 
of lactic bacteria has in all cases approached very nearly to 100 
per cent., one sample giving as low a percentage as 97, but 
most of them being 99 to 100. ‘This was found to be the case 
in all of the numerous experiments which we have carried on 
in the last two years. ‘The species of bacterium is usually 
Bact. lactis acidi (No. 206 ). 
g. At the time of curdling the actual number of bacteria 
found showed the greatest irregularities. This is not indicated 
in the table, but, briefly, the number found varied from 211,- 
000,000 bacteria per cubic centimeter in one single case to 
2,700,000,000 bacteria. These numbers had no relation, so far 
as could be seen, to the time of curdling. 
10. The amount of acid present in the milk at the time of 
curdling showed somewhat surprising variations. In most 
cases it was from .6 to .8 per cent.; but in one case it was 1.15, 
and in the other sample of the same date, 1.23. The reason 
for this wide difference in the amount of acid present at the 
curdling point we cannot at present explain. 
