164 S. J. HOLMES. 



water is certainly of no service to it in leading it into its accus- 

 tomed habitat if it should,, for any reason, become removed from 

 it. In the air and near a bright light Ranatra becomes, sooner 

 or later, strongly positive, often being wrought up to the highest 

 pitch of excitement in its efforts to reach the light. Of the util- 

 ity of such curious behavior it is indeed difficult to conceive a 

 reasonable explanation. 

 UNIVERSITY OF WISCONSIN, 

 MADISON, Wis. 



