New YorK AGRICULTURAL EXPERIMENT STATION. 43 
sented, nor have we attempted to establish the relation between 
slight variations in the flavor of the cheese samples and varia- 
tions in the yeast flora. 
SWEET FLAVOR PRODUCED BY YEAST STARTERS, 
In discussing the causal relation of any organism either to a 
disease or to a fermentation it was formerly the custom to ignore 
all other factors than the mere presence of the germ. The fallacy 
of this method of reasoning has come to be recognized in medical 
matters and our experience detailed below, as well as the results 
of our study of the activity of the organism producing rusty spot, 
shows that the accompanying conditions exert a profound influ- 
ence upon the activity of fermentative organisms. The fact that 
sweet flavor in a factory undergces seasonal and even daily varia- 
tions in its activity would suggest the same idea. In beginning 
experimental work upon such an untried field as the relation of 
yeasts to cheese flavor, it is not surprising that the results have 
not been uniformly good. By referring to the article on rusty 
spot it will be seen that, while in a majority of attempts the use 
of a starter of the causal organism resulted in failure so far as a 
real reproduction of the typical trouble was concerned, yet when 
the right conditions were obtained this same organism repro- 
duced the rusty spot in even more marked form than is met with 
in the factories. 
The starter used with a majority of the cheeses made in this 
connection was prepared from a pure culture of a yeast which is 
designated in the laboratory as 2F. This yeast was isolated 
from a cheese showing a well-marked case of sweet flavor. In 
each of these experimental cheeses there was reproduced in a 
slight degree the characteristic flavor of the original cheese. 
The determination of this fact rests not only upon the judgment 
of one of us, but has been subscribed to by a number of experts 
to whom these cheeses have been submitted. However, it must 
be said in all fairness that the sweet flavor reproduced in these 
experiments fell short of the intensity often met with in fac- 
