Art. VII.] Weinzirl, Bactevia in Cheese. 15 1 
ods were not adapted to the isolation of the latter class but we 
now know that peptonizers are not abundant nor are the species 
numerous in most kinds of cheese. Hence it is quite possible 
that several, if not most of Duclaux’ species, were duplicates 
of each other. 
For nearly a score of years little progress was made. A 
more accurate knowledge of the chemical products of the curing 
process was obtained; also a better knowledge of the bacterial 
flora. From the latter point of view, Adametz’^ work deserves 
especial mention, for he isolated nineteen species of bacteria from 
Emmenthaler cheese — six micrococci, five sarcina and eight bac- 
illi. These different species were described, and their physiolog- 
ical activity noted. He found too, that soft cheese contained a 
greater numerical percentage of germs than hard varieties ; that 
the number increased as the cheese ripened, reaching as high as 
850,000 per gram of cheese. Where disinfectants were added 
to the cheese the germ content decreased and ripening proceeded 
more slowly or ceased entirely. This latter observation the 
writer has not been able to corroborate and remains quite inex- 
plicable in the light of our present knowledge. 
Of yet greater importance was the able work of Von Freu- 
denreich,^ who also investigated Emmenthaler. He isolated a 
number of species, and made quantitative determinations of the 
germ content. Earlier investigators had found numerous pep- 
tonizing bacteria, with relatively few non-preptonizing forms. 
Von Freudenreich found on the contrary, that the former 
class was relatively small in numbers and belonged to the classes 
of Hay and Potato bacilli ; the latter class predominated and 
frequently constituted the only bacteria present. These he 
found to belong to the class of lactic-acid-producing germs. 
Thus it appeared that if cheese was ripened by bacteria, the for- 
mer theory was no longer tenable ; that casein digesters took 
^ Adamatz Bakteriologisch Untersuchung uber den Reifungs prozess der 
Kase. Laudw. Sahrbucher XVII, 1897, pp. 227-269. 
Von Freudenreich, Weitere bakteriologische Untersuchungen iiber den 
Reifungs prozess des Emmenthaler Kases. Land. Jahrbucher des Schweiz. 
VIII, 1894, pp. 207-239- 
