48 



C. H. TURNER. 



toward the water, 16 per cent, toward the sun and 26.6 

 per cent, toward the initial position of the head. The low per 

 cent of movements toward the water is too low to warrant the 

 conclusion that the group, as a whole, is directed, in its move- 

 ments, by the nearest body of water. However, certain indivi- 

 duals are undoubtedly so influenced. Two individuals made 100 



TABLE VII. 



WATF.R-STRIDER (Gerris remigis Say). 



per cent, of movements toward the water; one, 80 per cent; four, 

 between 50 and 60 per cent. On the other hand it must be noted 

 that three individuals made 100 per cent, of their movements 



