34 E. J. LUND 



2. Effect of mass or volume upon the extrusion reaction 



From previous observations it had become evident that extru- 

 sion depended in some way upon the quantity eaten, and accord- 

 ingly the following experiment was carried out: 



Experiment VIII (table 7, fig. 8). Three sets, A, B and C, of 48 

 individuals each, were fed fresh yolk. Individuals of Set A were fed 

 1 grain each, those of Set B, 3 grains each, while those of Set C were 

 permitted to eat a considerable number of grains, at least 5 or more. 

 Several of Set C ate 12 to 15 grains. The number of grains present in 

 each individual of Set C was counted when the first record was taken, 

 3 hours after feeding. Several individuals of Set C had by this time 

 extruded a number of the grains eaten three hours previously. 



The count of the number of grains present in each individual 

 of Set C was not made immediately after feeding, because it be- 

 comes increasingly difficult to count the number of grains in 

 active individuals that have eaten more than 7 or 8 grains. The 

 average number of grains in each individual of Set C, three hoiirs 

 after feeding, was 5.64. The number of grains in each varied 

 from 4 to 7. The total number in the 48 individuals Set C, 

 at the end of three hours was 271 grains. 



Records of the number of grains in each individual of the three 

 sets were taken 3, 5, 7, 9, 12, 14, 16, 24 and 30 hours after feed- 

 ing. The results are given in brief in table 7, and by the curves 

 in figure 8. The Curves A, B and C show the relative rates of 

 total loss of the fresh yolk by Sets A, B and C, respectively. 



The table shows that the total number of grains present in all 

 the individuals of each set, decreases with increase in the length 

 of time after feeding. The rate of decrease in these numbers is 

 on the average in the order: Set C> Set B> Set A. This 

 becomes more apparent if we calculate the percentage of the total 

 number of grains fed which was present in the individuals at the 

 times when the records were taken. In order to bring out these 

 relations more clearly the curves in figure 8 were plotted from the 

 percentages given in table 7. 



Now, from what has thus far been said, and from the records, 

 we have no proof that the loss in the number of grains which did 



