Spiders. 1 1 1 



which radiating blind pouches pass off, and the diges- 

 tive tube is short. 



Near the hinder end of the abdomen in spiders, 

 there is a flattish ' spinning area ' upon which open the 

 glands which secrete the web. On this area there are 

 usually three pairs of little wart-like spinnerets ; and 

 numerous small pores, from each of which a minute 

 thread of web-material issues, open on the surface of 

 each spinneret. Sometimes one pair of the little knobs 

 consists of a palp-like process. In the common 

 house-spider (Tegenaria domestica) there are 400 such 

 holes on each wart, hence each thread of the web 

 consists of several hundred strands ; the material is at 

 first fluid, but rapidly becomes hard and chitnoid. 

 In commencing to spin, the spider applies the spin- 

 nerets to the surface of some fixed body, and then as 

 it moves away, the material is drawn out. The hind 

 feet press the several strands of the web-thread to- 

 gether, their comb-like claws appearing to be im- 

 portant instruments for this purpose. 



In the web of the garden spider, whose geometrical 

 nets are frequently seen on old fences and palings, 

 tli ere are three kinds of threads to be noticed, ist 

 The marginal and stoutest radial threads. 2nd. The 

 intermediate radial threads, both of which are uniform, 

 though differing in size and in elasticity, wherein the 

 secondary exceed the primary. 3rd. The concentric 

 threads which are bedecked at regular intervals with 

 little viscid globules. 



Other spiders excavate cavities in the ground ; these 

 they line with a silky web, and over the mouth of 

 them they make a trap-door lid of alternate layers of 



