MIMICRY. 451 



of fish, frogs, and tadpoles, some of which may probably be 

 attracted within reach by mistaking the appendages on the neck 

 for plants or animals on which they feed."* " There occurs at 

 the Cape of Good Hope a harmless egg-eating Snake (Dasypeltis 

 scabra), which flattens its head, coils as if for a spring, hisses, 

 and darts forward as though about to strike in a way that closely 

 resembles the characteristic mode of the Berg-Adder (Vipera 

 atropos), of which it is mimetic. It is really quite harmless, 

 subsisting on eggs, the shells of which are broken in the throat 

 by the enamel-tipped processes of the vertebrae, which project 

 into the gullet, and form the so-called gular teeth ; but its re- 

 semblance both in form and behaviour to a venomous Snake pre- 

 sumably affords it protection from enemies."! 



When we approach the annals of entomology,! we find this 

 explanatory idea permeating the whole subject. To suggest a 

 new instance of mimicry is considered more desirable by many 

 than to describe a new species ; while the advocates or followers 

 of both procedures do not always seem to practise mutual 

 admiration. The observations are not all modern. The old 

 Swedish traveller in South Africa, Dr. Sparrmann, who first dis- 

 covered (1775) the curious hemipteron, Phyllomorpha paradoxa, 

 was impressed by its mimetic resemblance to a leaf. "At noon- 

 tide I sought for shelter among the branches of a shrub from the 

 intolerable heat of the sun. Though the air was now extremely 

 still and calm, so as hardly to have shaken an aspen leaf, yet I 

 thought I saw a little withered, pale, crumpled leaf, eaten as it 

 were by caterpillars, flittering from the tree. This appeared to 

 me so very extraordinary that I thought it worth my while sud- 

 denly to quit my verdant bower in order to contemplate it ; and 

 I could scarcely believe my eyes when I saw a live insect, in 

 shape and colour resembling the fragment of a withered leaf, with 

 the edges turned up and eaten away, as it were by caterpillars, 

 and at the same time all beset with prickles. Nature, by this 

 peculiar form, has certainly extremely well defended and con- 

 cealed, as it were in a mask, this insect from birds and its other 



* 'Eoyal Nat. Hist.' vol. v. p. 91. 



f C. Lloyd Morgan, ' Habit and Instinct,' p. 12. 



J Poulton has focussed many observations respecting instances in the 

 Insecta, largely augmented by information received from the well-known 

 coleopterist, C. J. Gahan. (Gf. ' Journ. Linn. Soc' xxvi. pp. 558-612 (1898)). 



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