THE SERPENT'S TONGUE 145 



there are vulnerable spots and weak joints in the 

 defensive armour of all animals. What I wish to 

 draw attention to is the fact that, speaking meta- 

 phorically, the serpent, of all creatures that kill 

 their own meat, is the most unsportsmanlike in its 

 methods, that it has found out and subtly taken 

 advantage of the most secret and unsuspected 

 weaknesses of the animals on which it preys. 



We have seen how the common snake catches 

 the frog; but frogs are found only in wet places, 

 and snakes abound everywhere, and the sedentary 

 snake of the dry uplands must feed on the nimble 

 rodent, volatile bird, and elusive lizard. How does 

 he manage to catch them? For considering how 

 alert and quick-sighted these small hunted creatures 

 are, it must, I think, be assumed that the snake 

 cannot, except in rare instances, approach them 

 unseen and take them unawares. I believe that 

 in many cases the snake succeeds by approaching 

 its intended victim while appearing to be stationary. 

 This stratagem is not confined to the ophidians: 

 in a somewhat different form it is found in a great 

 variety of animals. Perhaps the most familiar 

 example is afforded by the widely distributed 

 hunting-spider. The plan followed by this spider, 

 on a smooth surface where it cannot hide its form, 

 is to advance boldly towards its prey, and when 

 the fly, who has been suspiciously watching its 

 approach, is about to dart away, to become motion- 

 less. This appears to excite the fly's curiosity, and 

 he does not take flight; but very soon his restive 



