ARACHNIDA 379 



which are set in different directions, so as to command a wide field 

 of vision. 



On the head of an insect, too, are two horns, or antenna, as they 

 are more properly termed. These may be long and slender, short 

 and stout, plumed, knobbed, clubbed, or saw-like; but in some form 

 or other they are always present. 

 Spiders, however, do not possess 

 them. 



Once more, an insect passes 

 through three transformations be- 

 fore it attains to its perfect state. 



Spiders, however, undergo no 

 such changes of form. When -c- <-c j c at? 



j,v. v^i ivy. lii. vvjii„ij i, Eyes of Spider. 2, Compound Eyes 



hatched they are as perfect as of Common Fiy 



their parents in all but size. As 



they grow, these little spiders, like the grubs of insects, throw off 

 their skins at intervals; but the change of raiment brings with it 

 no corresponding change of form. 



Many insects and many spiders spin silken webs. The insects 

 do so to provide themselves a habitation, or as a means of pro- 

 tection from their enemies; but spiders make their nets in order 

 to entrap their prey. 



In spring and summer we may find spiders' webs everywhere; 

 in the trees, in the bushes, in the grass, in greenhouses, out- 

 houses, and sheds. Everywhere the silken nets are hanging. If 

 we examine them we shall probably find that they contain the 

 remains of insects which have been entangled in them, and partly 

 devoured by the spiders that set them. 



The spider's threads are spun from a thick, glutinous liquid 

 of a pale yellowish colour. This is the silk, in its original form. 

 Until it leaves the body of the spider it is nothing more than 

 a gummy fluid. But it possesses the property of hardening as 

 soon as it comes into contact with the air, and thus assumes the 

 form in which we know it. 



At the end of the spider's body are minute organs called 

 spinnerets, and each of them communicates with one of the silk- 

 producing glands. When the spider spins a net, it touches with 



