The Life of Spiders 



species that have an epigynum, this organ is not exposed till the 



last moult takes place. At this time too, the abdomen of the 



female may undergo a marked change in form, due to the growth 



of the eggs within it. The 



males of the hackled-thread 



weavers lose the cribellum and 



calamistrum at the last moult 



or have these organs greatly 



reduced. 



The reproduction of lost 

 organs. — The reproducing of 

 legs that have been lost by 

 immature spiders is frequently 

 observed. If a leg be lost by 

 a young spider the wound soon 

 heals, and at the succeeding 

 moult the bud of a new leg 

 appears. This bud increases in 

 size at each succeeding moult; 

 and in time, if the process 

 begins early enough in the life 

 of the spider, a functional leg 

 is obtained. Figure 183 repre- 

 sents a spider in which two legs, the left fore leg and the 

 right hind leg, were being reproduced; this is a mechanical 

 reproduction of a photograph of a spider in our collection. 



Fig. 183. 

 A SPIDER REPRODUCING LOST LEGS 



III.— THE FOOD OF SPIDERS 



All spiders are carnivorous. Their prey consists chiefly of 

 insects; but they will feed on other spiders that they can overcome, 

 even on weaker members of their own species. This cannibalism 

 is not confined to that of young spiders described in the preceding 

 section, but is also true of adults. It is a common occurrence for 

 the female to destroy the male of its own species, which is smaller 

 and weaker. 



Besides insects and spiders other small animals are occasion- 

 ally destroyed by these voracious creatures. The most striking 

 instance of this is the destruction of small birds by a large South 

 American tarantula, the bird-spider {Avicularia avicularia). 



185 



