RELATIONS OF BURSARIA TO FOOD 



21 



The results are uniformly less than those found by experiment 

 (column 2). 



Now since we have constructed a limiting case for the maxi- 

 mum average rate of digestion on the assumption that the rate 

 is in direct proportion to the surface of substrate exposed, we 

 may on the same assumption establish a limiting case for the mini- 

 mum average rate of digestion, by assuming that the surfaces 

 exposed to digestive action in the four sets, are to each other as 

 the surfaces of spheres of vitellin having volumes 1, 2, 3 and 6. 

 Calculating this on the basis of the rate of digestion found by 

 experiment for one grain (Set A), we obtain the values given in 

 column 4, table 5. It will be noted that these values, based on 

 the above assumption are all greater than the values found by 

 experiment. The results of both experiments agree. However, 

 the intermediate position of the obtained results (column 2, 

 table 5) does not exclude the possibility that the digestive process 



TABLE 5 



Summary of and calculations for the average velocity of digestion of vitellin, based 

 on results of Experiments III and IV, tables 3 and 4 



