HYDROTROPISMS OF FRESH-WATER INVERTEBRATES. 



TABLE IX. 



THE WHIRLIGIG BEETLE (Gyrinus sp. ?.) ADULTS. 



were placed in a dry tray forty feet from the water. In less than 

 half an hour all had flown to the water. In most cases they did 

 not ascend high in the air; but the further back they were the 

 higher they ascended. In one case a sidewise flight carried t he- 

 beetle behind a tall tree. In that case it arose to above the top 

 of the tree before turning toward the water. 



At 3:15 P.M. the eyes of ten individual-; were blinded by paint- 

 ing them with lampblack mixed in liquid :Jue. The-e whirlL 

 were placed in a dry tray forty tVet from the water. Ten normal 

 individuals were placed in a similar tray, at the -ame di-tance 

 from the water. The two trays were only t\\> feet apart. One by 

 >ne, the individuals with normal >ight an>-e fn-m the tray and 

 tlew to the water. By 3:30 P.M. all but <ne had reaehed the 

 \\.iter. At 4:00 P.M. the last one tlew to the water. Up to 



