RELATION OF BURSARIA TO FOOD 



21 



TABLE 4 

 Experiment I 



A 



B 



Fig. 3 Showing the relative concentration of yolk in dishes A and B of Ex- 

 periment 1. 



h. Effect of m 

 on feeding. 



echanical stimulation and of mechanical injury 



Experiment II. Thirty individuals from the same culture, starved 

 twenty-four hours, were placed in each of six 8 cc. dishes containing 

 5 cc. tap water. Before feeding, the animals in three of the dishes 

 (Set 1 in the experiment) were mechanically stimulated by means of 

 a pipette. The opening of the latter was about ten times the width 

 of Bursaria. The edges of the opening were made smooth by melting. 

 The animals of Set 1 were stimulated bj^ drawing them up into the 

 pipette along with the tap water in the 8 cc. dishes, four times. Equal 

 quantities of yolk suspension were now added to all the dishes. After 

 having fed ten minutes the animals of Set 1 were again stimulated by 

 drawing them along with the yolk suspension into the pipette two 

 times; at the same time the control, Set 2, was stirred by gently shak- 

 ing the dish and not allowing any, instrument to touch the animals; 

 hence the distribution of the yolk was the same in the two sets of 

 dishes. All the individuals in Set 1, after having been stimulated, 

 were perfectly normal and not injured. They looked like those of the 



