IN DEFENSIVE COLORATION 367 



Ing and convincing suggestion would, however, apply 

 to Batesian Mimicry as well as to Synaposematic 

 Resemblance. 



7. Remarkable Examples of Mimicry. — Many instances 

 of Mimetic Resemblance between forms of all degrees of 

 affinity have been given in Essays VIII and IX. They 

 have been drawn from the Arthropoda and almost 

 exclusively from the Insecta, the group in which these 

 superficial likenesses are developed far more extensively 

 than in all the others put together. 



Mimicry is known, although instances are relatively 

 rare, among the Vertebrata. Thus the venomous South 

 American snakes of the genus Elaps are mimicked by 

 harmless species inhabiting the same areas ; defenceless 

 birds such as the cuckoos and orioles mimic powerful 

 aggressive species living in the same countries, and, in 

 Malaya, tree-shrews mimic the more powerful squirrels.^ 



The terrifying appearance assumed by certain large 

 caterpillars, e. g. the British Choerocampa elpenor (the 

 Elephant Hawk Moth), is founded upon the mimicry, or 

 rather the caricature of a cobra-like serpent. Many 

 observations prove that terror is undoubtedly inspired 

 by the appearance, in man no less than in insect-eating 

 animals. It is probable that these are examples of true 

 Batesian Mimicry — Pseudaposematic Resemblance. In 

 an experiment made by the present writer in 1887, a large 

 lizard, Lacerta viridis, was for some time immensely 

 terrified by the larva of elpenor. When, however, the 

 lizard eventually succeeded in overcoming its fright, it 

 devoured the caterpillar with apparent relish.- It is 



^ For details consult A. R. Wallace, On Natural Selection, London. 

 1875, PP- I0I-7- Mr. Shelford informs me that the tree-shrews certainly 

 possess distasteful qualities and yet that they are undoubtedly the mimics. 

 It is not improbable that the resemblance is Miillerian. The interpreta- 

 tion of the likeness as aggressive — the shrews being enabled under the 

 disguise of squirrels to approach their insect prey — has broken down in 

 somewhat analogous cases (see p. 378), and would require a great deal 

 of confirmatory evidence before it can be accepted as probable. 



^ Colours of Animals, London, 1890, p. 261. For other earlier 

 observations on the same species consult the same work, pp. 258-60, 

 also Proc. ZooL Soc, Lond., 1887, pp. 204, 206-7. together with the 



