ioo OUR INSECT FRIENDS AND FOES 



water-weeds, and these threads also act as tele- 

 graph lines, warning the Spider when resting 

 within her nest of the approach of prey or foes. 

 When the waterproof silken nest has been con- 

 structed, the Spider ascends to the surface and 

 for a moment sticks her body out into the air ; 

 she then rapidly descends, taking with her a 

 supply of air imprisoned by the fine hairs cover- 

 ing her abdomen. She at once enters her nest, 

 and proceeds to comb out the imprisoned air 

 bubbles with the aid of her comb-like feet. 

 Again and again she visits the surface and 

 returns with a fresh supply of air, which she at 

 once discharges under her dome-shaped nest 

 until it becomes inflated by the imprisoned air, 

 after the fashion of a diving-bell, and looks as if 

 filled with quicksilver. Within the diving-bell 

 home the Water-Spider spends the greater part 

 of its life, only quitting it in search of food, or 

 to bring down a fresh supply of air to replace 

 that which has been exhausted. 



