SPIDERS 



93 



and its juices are sucked by the alternate expansion 

 and contraction of the throat. By this means mites, 

 red spiders, and ticks devastate our currant-bushes 

 and hop-plantations, destroy cheese, books, and fur- 

 niture, become blood-suckers of man and most ter- 

 restrial animals, and in tropical countries are one of the 



Fig. 19. — Wheel-web of the Garden Spider. — (After Blanchard.) 



means whereby such diseases as relapsing fever are 

 transmitted. Spiders are one of the dominant races 

 of animals, and in hunting instincts excel all others. 

 Their power of constructing webs, underground traps, 

 and even sub-aquatic snares, is well known, but the 

 variety of traps and the ways in which these snares 



