154 A NATURALIST IN HIMALAYA 



thorax of an insect be penetrated with a pin or even 

 the interior of the thorax entirely destroyed, the legs 

 and wings are not paralyzed for a long time, possibly 

 for days, yet the destruction of tissue is much greater 

 than that produced by the spider's fangs. The rapid 

 paralysis seems therefore to be due very probably to 

 the injection of a minute quantity of a powerful nervous 

 poison. 



The Hippasa lurks at the entrance to its tunnel 

 with its subtle snare spread out before it. There 

 would seem to be little doubt that it is waiting and 

 watching for its prey. But this may not be strictly 

 true, for the sense of sight does not appear to be very 

 acute in these spiders. They are directed towards 

 their prey by the help of the vibration of the snare 

 rather than by the power of vision. It is possible to 

 move a fine needle from side to side in front of the 

 spider's head without it showing any sign of being 

 aware of the strange object, but touch one of the 

 filaments ever so gently with the needle and the spider 

 is off at lightning speed. I also noticed in some 

 examples, which I kept captive in a box, that they 

 were able to detect the aerial vibrations caused by 

 buzzing flies, but would be quite oblivious of their 

 presence when the insects crawled close by along the 

 floor of the box. But once a fly touched a filament 

 then the spider became instantly alert and darted 

 towards the capture. 



The pedipalps are to the spider what the antennae 

 are to an insect, or the hands to a human being. 

 They are all-important organs on which the creature's 

 livelihood depends. Neither does the sense of hearing 

 nor that of smell reside in the pedipalps, for the 



