74 STORRS AGRICULTURAL EXPERIMENT STATION. 
ACKNOWLEDGMENT. 
Aside from such obligations as are mentioned in the discus- 
sion of special topics, the author wishes to acknowledge the 
assistance of the following members of the Experiment Station 
staffi—Dr. B. B. Turner, Proféssor W. A. Stocking, Mr. A. W. 
Bosworth, and Mr. T. W. Issajeff, in numerous cases where the 
work of each presupposes the results of the other, and especially 
to acknowledge the constant assistance of the Supervisor of the 
investigation, Dr. H. W. Conn, with whom the cheese prob- 
lems have been fully discussed at every stage of the investigation. 
CAMEMBERT. RESUME OF PREVIOUS PAPERS. 
The biological conditions and the physical changes encoun- 
tered in the production of a Camembert cheese from market 
milk may be restated from our former bulletin as a basis for 
defining the special problems of the mycologist. 
Milk as ordinarily received contains bacteria of many species 
and the germinating spores of numerous fungi from the stable 
and from the food of the cattle. When such milk is curdled 
for cheese making, representatives of all of these species are en- 
closed in the mass or coagulum. Freshly made cheese from 
this curd, then, may contain any species of mold or bacterium 
found in the locality, which is capable of living in milk or its 
products. The first step in the ripening of a Camembert cheese 
is the production of lactic acid. The lactic bacteria* very soon 
increase their rate of multiplication so enormously as to become 
entirely dominant. The acid produced by these forms soon 
reaches a per cent. sufficiently high to restrict the further 
growth of nearly every other species of bacteria, and even to 
eliminate the organisms themselves when present. In a time 
varying from a few hours to three or four days, according to 
the proportional numbers of these antagonistic species at the 
start, further bacterial growth seems to be entirely stopped. 
Bacterial development can not begin again until this acidity is 
reduced below the critical point for the species involved and 
even then, since the acid is neutralized on the outside first, for 
most species, it begins at the surface and works slowly inward. 
The uncertainties due to the presence of many species of bacteria 
in the milk are in this way avoided by the natural, simple and 
practically universally successful process of souring. 

* Storrs Agricultural Experiment Station Bulletin No. 35, p. 2s. 
