302 



NATURAL HISTORY. 



arrangement is the securing 

 of greater strength to the 

 thread, for it is well known 

 in rope-making that, in cords 

 of equal thickness, those 

 which are composed of many 

 smaller cords are stronger 

 than those which are spun 

 at once. Another advant- 

 age still is, that these minute 

 threadlets can be better at- 

 tached to an ob- 

 ject than a single 

 thread. When 



Fig. 235. Spider's Threads coming from , Q ., , 



the spinnerets. the opider makes 



an attachment of his thread, he presses the spin- 

 nerets against the spot selected, and thus fast- 

 ens the ends of the threadlets projecting from 

 the holes over quite a space. This is seen in 

 Fig. 236, which represents an attachment of 

 this kind, as seen with the microscope. Fig - 236 - 



514. The foot of a Spider, a magnified view of which 



is given in Fig. 237, 

 has three claws, one 

 of which acts as a 

 sort of thumb, and 

 the others are tooth- 

 ed as a comb. It is 

 supposed that these 

 combs are used hi 

 preventing tangling of the threads in the web, and also 

 in removing any particles that may become attached to 

 it. When a Spider has let itself down from any place 

 by its thread, if it goes up again upon it, it gathers up 

 the thread into a ball with its claws and throws it away. 

 So, also, if any part of its web is rendered useless by any 

 thing which becomes attached to it, it is separated from 



Fig. 37. Triple-clawed Foot of a Spider, mag- 

 nified. 



