The Life of Spiders 



injured by the passage of the spider. This is apt to occur when 

 the angle between the trapline and the plane of the orb is small; 

 the spider, when rushing up the trapline, may touch and bring 

 together several turns of the viscid line with each forward move- 

 ment of one of its legs, a projecting knee reaching the orb. Such 

 a trail is shown on the left side of the orb represented by Fig. 

 194. The trapline is shown indistinctly behind the orb; the 

 retreat was in the curled leaf at the upper left corner of the orb. 



VIII.— THE NESTS OF SPIDERS 



The nest-building habit is found both among spiders that 

 build webs and among those that do not; and the forms of the 



nests are even more 

 numerous than are 

 the types of webs. 



Among the spiders 

 that live on the 

 ground are some 

 that make their nests 

 in the earth. The 

 most common nests 

 of this type are the 

 tunnels of the wolf- 

 spiders (Lycosidae). 

 These vary from a 

 simple vertical shaft 

 with a delicate silken 

 lining to one in which 

 the entrance is sur- 



Fig. 195. RETREAT OF ARANEA THADDEUS mOUllted by 3. turret 



or watch-tower (Fig, 

 722). Even more remarkable than these are the nests of 

 the trap-door spiders in which the entrance is furnished with a 

 hinged door (Fig. 216), and, frequently, with a second door at 

 some distance from the entrance; and still more remarkable is 

 the silken, tubular nest of the purse-web spider. (Fig. 228.) 



Very many spiders, representing widely different families, 

 make nests by folding or rolling leaves and lining the enclosed 

 space with silk. This type of nest is made by the Clubionids, 



206 



