FOOD OF INSECTS. 407 



from a height by her line, stop her progress at any 

 point of her descent: and, according to Lister% she is 

 also able to retract her threads within the abdomen ; 

 but this is doubted, and with apparent reason, by De 

 Geer\ 



The only other instruments employed by the spider 

 in weaving are her feet, with the claws of which she 

 usually guides, or keeps separated into two or more, the 

 line from behind ; and in many species these are admi- 

 rably adapted for the purpose, two of them being fur- 

 nished underneath with teeth like those of a comb, by 

 means of which the threads are kept asunder. But 

 another instrument was wanting. The spider in ascend- 

 ing the line by which she has dropped herself from an 

 eminence, winds up the superfluous cord into a ball. 

 In performing this the pectinated claws would not have 

 been suitable. She is therefore furnished with a third 

 claw between the other two*", and is thus provided for 

 every occasion. 



The situations in which spiders place their nets are 

 as various as their construction. Some prefer the open 

 air, and suspend them in the midst of shrubs or plants 

 roost frequented by flies and other small insects, fixing 

 them in a horizontal, a vertical, or an oblique direc- 

 tion. Others select the corners of windows and of 

 rooms, where prey always abounds ; while many esta- 

 blish themselves in stables and neglected out-houses, 

 and even in cellars and desolate places in which one 

 would scarcely expect a fly to be caught in a month. 

 It is with the operations of these last especially, that 



^ Hist. Jniin. Jng. p, 8. '' De Geer, vii. 189. 



Leeuw. Oj^usc. iii, 317. f. 1. 



