416 FOOD OF INSECTS, 



lated, it is clear that the main line of the net can never 

 be longer than the height of the object from which the 

 spider dropped in forming it. But it is no uncommon 

 thing to see nets in which these lines are a yard or two 

 long, fastened to twigs of grass not a foot in height, 

 and yet separated by obstacles effectually precluding 

 the possibility of the spiders having dragged the lines 

 from one to the other. Here therefore some other 

 process must have been used. 



Both these difficulties would be removed by adopting 

 the explanation of an anonymous author in the Journal 

 de Physique^^ founded as he asserts on actual obser- 

 vation. He says that he saw a small spider, which he 

 had forced to suspend itself by its thread from the point 

 of a feather, shoot out obliquely in opposite directions 

 other smaller threads, which attached themselves in 

 the still air of a room, without any influence of the 

 wind, to the objects tow ards which they were directed. 

 He therefore infers that spiders have the power of 

 shooting out threads and directing them at pleasure to- 

 wards a determined point, judging of the distance and 

 position of the object by some sense of which Ave are 

 ignorant. Something like this manoeuvre I once myself 

 witnessed in a male of the small garden spider (Aranea 

 reticulata). It was standing midway on a long perpen- 

 dicular fixed thread, and an appearance caught my eye 

 of what seemed to be the emission of threads from its 

 projected spinners. I therefore moved my arm in the 

 direction in which they apparently proceeded, and, as 

 I suspected, a floating thread attached itself to ray coat, 



*.'/«. %ii. Vi!xd(7v.iahe. Tra'uLi'.ed in Phil. Jlag. ii. 275. 



