GROWTH 



253 



Two good experiments have been given by Graham- 

 Smith (1920). Table 70 shows the slow growth to high 

 numbers at low temperatures, and the rapid growth to 

 to less high numbers near the optimum. 



In another experiment, the maximum numbers were 

 reached at 



33°C. after 4 days 10,610,000 



27°C. after 4 days 18,671,000 



At 8-10°C., no growth occurred, and a very gradual 

 decrease of the numbers of living cells was observed. 



Henneberg (1926, p. 179) found that yeast will give larger crops 

 by weight at low temperatures, but that the total amount of yeast 

 protein formed is higher at high temperatures. The following data 

 are given: 



a. Multiplication at 20°C.: 6.4 fold, at 30°C.: 9 fold 



Not quite comparable with these data is the experiment 

 by Stern (1901) who obtained the following final yeast 

 crops in 100 c.c. of a 10% glucose solution with 0.3% 

 asparagin and minerals (Table 71). 



