254 



PHYSIOLOGY OF BACTERIA 



The yeast cultures were not aerated. At 21°C., the 

 maximal crop is reached, and also the maximal produc- 



tion of yeast protein, though this yeast contains less 

 nitrogen than that grown either at higher or at lower 

 temperatures. The temperature of the maximal crop is 

 a good deal lower than the optimum temperature of 

 growth. 



SUMMARY 



The temperature which gives the largest crop is con- 

 siderably lower than that giving the most rapid growth 

 rate, but it is still far above the minimum temperature of 

 growth. 



An increase above the optimum temperature causes a 

 very rapid decline of the crop. 



The temperature of the largest crop weight and that of 

 the largest amount of protein in the crop are not exactly 

 the same. 



(/) ENDPOINT OF GROWTH AND CHEMICAL STIMULANTS 



It is generally understood that the final growth in 

 any culture will depend not only upon the amounts and 



