ACTIVITIES OF THE AMAROUCIUM TADPOLE 



255 



of the papillae. The struggles of the tadpole after its initial 

 attachment frequently cause the body to adhere at all three 

 points. 



DURATION OF THE FREE-SWIMMING PERIOD 



The duration of the free-swimming period in the cases of one 

 hundred tadpoles has been accurately determined with the 

 result shown in the diagram (fig. 4) . From this it may be noted 



Fig. 4 Diagram showing the duration of the free-swimming period of 102 

 tadpoles plotted to the nearest five-minute interval. 



that metamorphosis begins in some cases as early as ten minutes 

 after the escape of the tadpole from the parent colony and that 

 none of the tadpoles observed had an active period of longer 

 duration than an hour and forty minutes. It should be stated, 

 however, that in the experiments made to determine the reac- 

 tions of tadpoles to light and gravity, in each of which large 

 numbers of tadpoles were used, a few tadpoles in each case con- 

 tinued to swim for two hours. 



