92 REPORT OF DEPARTMENT OF BACTERIOLOGY OF THE 
In attempting to express the changes which take place in the flora 
as the process of manufacture proceeds there is difficulty in choos- 
ing proper units of measurement. Cubic centimeter and gram are 
the units universally used in work with milk and cheese respectively 
but when used together in a single study they do not express equiva- 
lent amounts. As similar observations have been made upon the 
germ content of the milk, whey and curd in the case of a number 
of cheeses a discussion of this phase of the question will be de- 
ferred until data from two more cheeses have been presented. 
No result from the commercial examination is given for this 
cheese partly because of the necessary absence of Mr. Smith at the 
dates of many of the analyses and partly because of the inherent 
difficulty of his giving an impartial judgment concerning his own 
product. The ripening progressed satisfactorily though slowly, as 
is to be expected with this type of cheese. 
It is seen that while the germ content of the milk at the time 
that the rennet was added was 16 millions per cc. that of the 
whey 2 hours later was only 10 millions per cc. This would sug- 
gest that through the coagulation produced by the rennet a con- 
siderable proportion of the germs were caught and held in the curd. 
Turning to the observations on the curd it is seen that during the 
time that the curd in the vat was undergoing the so-called ripen- 
ing process the bacteria multiplied from less than 3 millions to 
over 14 millions per gram. More surprising is the observation that 
after being put to press the germ content fell again in 3% hours to 
less than 2 millions per gram. On the following day it contained 
26 millions but from this point the germ content decreased at first 
rapidly and then more slowly. At 99 days there were still 1 million 
living germs per gram in the cheese. 
This cheese was conspicuous for its low germ content, the bac- 
teria present being pre-eminently of the lactic type. Yeasts were 
found in only two samples and then in small numbers. Liquefiers, 
though present, were not numerous and many plates did not show 
any. 
The number of organisms of each type present at each examina- 
tion as estimated from the colonies on the plates is given in Table 
so VLT, | 
