SO-CALLED GERMICIDAL PROPERTY OF MILK. EOS 
The striking features shown in these tables is the percentage 
of acid organisms, which decreases toward the end of the ex- 
periment instead of increasing as in the experiments described 
earlier; in one case amounting to only 2 per cent. at the end 
of twelve hours and in the other to but a fraction of I per 
cent. ‘This decrease in the percentage of acid organisms is, of 
course, due to the unusually rapid increase in the total num- 
bers in comparison with the increase of the acid organisms. 
The explanation of the condition of these samples of milk is 
found in a study of the species contained. In each of these 
samples, a single species of organism, which was not an acid 
producer, but, on the contrary, produced a strong alkaline con- 
dition in the medium, developed with unusual rapidity through- 
out the experiments. In Table 35 this organism constituted 15 
per cent. of the total number in the fresh milk. At the end of 
three hours it had increased to 19 per cent., at the end of six 
hours to 28 per cent. and at the end of nine hours to 32 per 
cent., while at the end of twelve hours it had increased with 
such rapidity that 167,500, or 60 per cent. of all the organisms 
present were of this one species. Upon isolation and later 
study this organism proved to be identical or very closely re- 
lated to No. 126 of Conn. 
In Table 35 the acid species in the fresh milk consisted of 
Bact. lactis acidi and a few miscellaneous species. These in- 
creased continuously, 2. lactis aerogenes appeared during the 
experiment, and these two types comprised most of the acids at 
the end of twelve hours. In Table 36 the acids in the fresh 
milk were of quite a miscellaneous nature, the principal species 
being Nos. 168 and 137 of Conn. None of the real lactic or- 
- ganisms appeared in the first set of plates. During the first 
few hours most of the miscellaneous acid organisms disappeared 
more or less completely, while the two species named continued 
throughout the experiment. Bact. lactis acidi made its appear- 
ance after the first few hours, and plates made at the end of 
three days revealed the fact that the acid organisms were prac- 
tically all of this species, the others having disappeared during 
that time. 
These experiments represent what may be considered as 
irregularities in the normal development of bacteria in milk. 
Here the unusual development of a single non-acid species not 
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