PROCURrNTG FOOD AND FEEDING. 



249 



Net 

 Jerking. 



dropped into the snare. Vertebrata at once rushed towards these, but find- 

 ing by her touch that they were dead matter, instead of leaving tlie ob- 

 , iects she drew them towards her with her feet, passed them to 

 ' her Hps and palps, where they were held a moment until bit- 

 ten entirely free from the lines. Then the fore feet were reached up, 

 and by a sharp snap of the claws the pieces were thrown downwards 

 out of the web. In this case, also, the Orbweaver was deceived. But very 

 generally she is able to distinguish between an artificial agitation and that 

 produced by an insect. At least, I have frequently failed to draw a spider 

 from her retreat by my most skillful manipulation of her snare. 



Blackwall is probably correct in his suggestion that tlie pulling mo- 

 tions which I have described are intended 

 to determine whether objects entangled in 

 the toils are animate or inanimate. ^ At 

 all events, it is true that by jerking the 



radii immediately in connection 

 Use of ^yjtij ^\^^i part of the ^lare in 



which the insects are entangled, 



and then suddenly letting go 

 their hold, the spiders produce a vibra- 

 tory motion in the net which seldom fails 

 to excite action in the ensnared insect. 

 Guided by the struggles of her prey, the 

 Orbweaver runs along the most contiguous 

 radii to seize her victim, avoiding contact 

 with the viscid lines as far as possible, and 

 drawing out after her a thread attached to 

 one of the lines near the centre of her 

 net, which serves to facilitate her return. 

 The manner in which insects are cap- 

 tured may be observed at any time, and 

 yet one may venture to describe the meth- 

 od-. When the insect strikes the viscid spirals, one or more legs and one 



or other or both of the wings, or an antenna are usually first to 

 Insect fggj ^j^g viscid grasp of the beads. The insect, at once arrested by 

 Entangle- ^-^^ \j\q^-^ begins to struggle, and finding itself fettered increases its 



efforts to be free. Sometimes, particularly if the viscid quality of 

 the beads be somewhat abated or the entanglement be slight, the insect suc- 

 ceeds in escaping. This occurs more frequently perhaps than is ordinarily 

 supposed. Very often, however, the struggles only result in fastening the 

 victim more securely by bringing additional poi-tious of the body into contact 

 with the spirals. Sometimes the insect will strike broad on in its flight, or 



Fio. 227, 



Epeira revolving captured fly while 

 enswathing it. 



1 Blackball, " Researches in Zoologj-," page 289. 



