New YorK AGRICULTURAL EXPERIMENT STATION. 47 
such an unsatisfactory condition there was little inspiration for 
the factory men to take more vigorous steps for its removal. 
In view of this incomplete knowledge of the subject and of 
the fact that some factories have suffered a considerable cut in 
the price of their output during a number of successive seasons, 
work was begun upon this line in the spring of 1899 and has 
been continued whenever opportunity offered since that time. 
ISOLATION OF THE CAUSAL ORGANISM. 
The first step was the isolation of the causal organism from 
affected cheese preliminary to the study of its behavior when 
introduced as a starter into a vat of good milk. Quite contrary 
to what would be expected from the published work upon the 
subject the isolation of the causal organism presented many 
difficulties. The red spots in the cheese are essentially colonies 
of the bacillus and the removal of a portion of one of these spots 
with a flamed needle gives approximately a pure culture, but in 
order to complete and make certain of the separation it is de- 
sirable to resort to plate methods. 
Lactose agar does not prove suitable since, quite coutrary to 
the ordinary rule, this organism refuses to produce color upou 
this medium; and no other basis of classification on agar is evi- 
dent. 
Gelatin plates seem to be but little more suited to the work 
becanse only at rare intervals is sufficient color produced in the 
colonies to characterize them. In some instances the germ eren 
refuses to grow upon gelatin when transferred from a potato 
culture, portions of the material carried over from the potato 
lying dormant in the gelatin for more than a week, yet when 
returned to a fresh potato surface setting up a vigorous growth. 
The culture media was for the most part made neutral to phe- 
nolphthalein with sodium hydroxide, but variations of acid and 
alkaline media have been tried with no better success. 
Cooked potato offers a very suitable medium for growth and 
production of color. Cut into slices and sterilized in Petri 
