476 



STATE BOARD OF AGRICULTURE. 



Degeneration of old 'broth-cultures. — Since the two tested strains of 

 lactic bacteria do not show mnch degeneration if transferred daily in 

 sugar-free media, it was tried in the following experiments whether a 

 continued sojourn in the sugar-free medium might have a more pro- 

 nounced influence. The following two series, with strains II and IV, 

 were carried out by Mr. W. W. Shanor. The milk culture was trans- 

 ferred several times in sugar-free broth, and from the last transfer three 

 flasks each containing 100 cc. of sugar-free broth were inoculated. After 

 certain time intervals, 1 g. of sterile lactose was added to these cultures 

 and growth and acid formation Avere followed closely. This method of 

 adding lactose is better than the transferring into milk practiced in the 

 above experiments since the latter introduces a new factor, the change 

 of medium. 



The results are given in Tables XXI and XXII. Strain II shows no 

 change whatever in the fermenting capacity in 6 days; strain lY showed 



