Xew York Agricultural Experiment Station. 47 



such an unsatisfactory condition there Avas little inspiration for 

 the factory men to take more vigorous steps for its removal. 



In view of this incomplete knowledjje 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 1890 and has 

 been continued whenever opportunity offered since that time. 



isolation op the causal organism. 



The first step was the isolation of the causal organism from 

 affected cheese preliminary to the study of its behavior wiien 

 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 

 difticulties. 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 jjlate methods. 



Lactose agar does not prove suitable since, quite contrary to 

 the ordinary rule, this organism refuses to produce color ui)ou 

 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 

 because only at rare intervals is sufticient color produced in the 

 colonies to characterize them. In some instances the germ even 

 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, yat 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 



