184 



With regard to the influence of sugar, there is, according 

 to Slator, a proportion between the size of the crop and the 

 initial concentration of glucose up to about 1 per cent. The 



fe75 



o 



" 2 45 



S 30 



o. 

 o 



o 



15 



«/5 

 CO 



■5 10 15 20 25 

 Gms. Glucose per 100 cc. 



Fig. 12. 



accompanying curve (Fig. 12) shows the retarding influence of 

 sugar in increasing concentration, when sugar is the limiting 

 factor. Its slope corresponds to 3900 X io 16 cells per gm., 

 a figure in fair agreement with the calculated number. 



In ordinary conditions of brewing the accumulation of 

 alcohol is never so great as to be a significant factor in the 

 growth of the yeast ; if, however, alcohol be present in ex- 

 cessive amount, it has a limiting action ; thus the presence 

 of 8 per cent, of alcohol in the fermenting liquor may inhibit 

 reproduction, especially if the supply of oxygen is limited. 



* Unit of crop of cells = 7-65 X io« cells per cc. 



