Hydration and Growth of Colloids and Cell-masses. 



113 



ing role. A much more pronounced effect, however, was secured at the 

 temperature of 31 C. (fig. 20). 



Plates of agar 90 and oat protein 10 parts which were 0.16 mm. in 

 thickness were swelled at a temperature of 31 C. at intervals of 2 

 hours or more, with the results given in table 88. 



TABLE 88. 



The acceleration, as expressed by the total during the first 4 hours, 

 was as 13 to 22 in the rise from 23 C. to 31 C., as 19 to 28 when the 

 first 8 hours is considered, and as 25 to 38 when the entire swelling is 

 taken into account. Raising the temperature to 39 C. gave swellings 

 as shown in table 89. 



TABLE 89. 



TABLE 90. 



Agar 90, oat protein 10. 



4 hours . . 



8 hours . . 



10 hours. . 



Swellings. 

 p. ct. 

 2,555 

 2,833 



2,888 



The acceleration accompanying this rise of 8 C. was followed by 

 an increase which was as 22 to 25 during the first 4 hours, 28 to 29 

 during the second 8 hours, and the hydration for the entire period was 

 actually less at this higher temperature. That the hydration passed 

 beyond the limits of acceleration and of total water-holding capacity 

 in this temperature region was denoted by the fact that swellings at 

 46 to 47 C. were as given in table 90. 



TABLE 91. 



It is to be seen that while the final capacity for swelling at 15 C. 

 had not been reached in 20 to 22 hours, it was practically complete 

 at 39 C. in 12 hours, as the continuance of the measurement would 



