RESEMBLANCES AMONG ANIMALS. 99 



constantly on the search for crickets with which to 

 provision their nests. 



Perhaps the most wonderful case of all is the large 

 caterpillar mentioned by Mr. Bates, which startled him 

 by its close resemblance to a small snake. The first 

 three segments behind the head were dilatable at the 

 will of the insect, and had on each side a large black 

 pupillated spot, which resembled the eye of the reptile. 

 Moreover, it resembled a poisonous viper, not a harm- 

 less species of snake, as was proved by the imitation of 

 keeled scales on the crown produced by the recumbent 

 feet, as the caterpillar threw itself backward ! 



The attitudes of many of the tropical spiders are 

 most extraordinary and deceptive, but little attention 

 has been paid to them. They often mimic other in- 

 sects, and some, Mr. Bates assures us, are exactly like 

 flower buds, and take their station in the axils of leaves, 

 where they remain motionless waiting for their prey. 



Cases of Mimicry among the Vertebrata. 



Having thus shown how varied and extraordinary 

 are the modes in which mimicry occurs among insects, 

 we have now to enquire if anything of the same kind 

 is to be observed among vertebrated animals. When 

 we consider all the conditions necessary to produce a 

 good deceptive imitation, we shall see at once that such 

 can very rarely occur in the higher animals, since they 

 possess none of those facilities for the almost infinite 

 modifications of external form which exist in the very 

 nature of insect organization. The outer covering of 



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