NOVEMBER 239 



to sting, although they are quite devoid of the 

 power of doing so. 



In the Filippine Islands there lives a grasshopper 

 of much discernment. He has remarked the ap- 

 pearance of the ladybird, and its immunity from 

 predatory foes ; so he has gradually acquired a 

 rounded shape and a general scheme of colour imi- 

 tating that unpleasant little beetle, and thus he 

 escapes his enemies. Another example is that of 

 the leaf-cutting ant, which is common in tropical 

 America. Every ant, when he goes home to tea, 

 carries with him a leafy umbrella about the size 

 of a sixpence, and another class of insects in the 

 neighbourhood also make a point, when they 

 are going home, of pretending that they too are 

 indigestible little ants, and imitate even the ant's 

 leaf very closely by a thin expansion, which de- 

 ceives all but the most acute observer. 



There are spiders which imitate ants, and hold 

 their forelegs as if they were antennae. They know 

 how delicious they are to the birds, and how un- 

 palatable are the ants, so they protect themselves 

 by mimicry. And some South American cater- 

 pillars even imitate snakes. They have eye-like 

 marks on each side of two of the body rings, and 

 when they are frightened they draw their rings 

 together in such a way as to exhibit the apparent 

 eyes, which, when seen through leafy boughs, give 

 an inconspicuous animal a terrifying appearance. 



A still more curious effect can be seen in the 

 caterpillar of the puss moth (Cerura vinula). This 

 larva, when undisturbed, has no very uncommon 

 appearance, but as soon as it is discovered it with- 



