-5^ 



THEORIES OE MIMICRY 



usual in Coleoptera, the legs are slender and wasp-like, 

 and are moved with wasp-like activity and jerkiness. In 

 spite of the apparent want of win^s, the effect produced 

 is \'ery considerable, and the majority of persons would 

 hesitate to touch the insect. This, then, is the method 

 adoi)tetl in the group of Clyiinac\ but in \arious other 

 allied tribes, such as the Nccydaliiiac, the K/iiiiolrai^i)iae, 

 the /:sf/iesi)iai\\.\\c CnIiii/DONiiuaciwuX others, the elytra, 

 which {o\'m by far the largest part of the visible dorsal 

 surface in the Clyti)un\ become greatly reduced so as to 

 show the under wings, which, folded over the back or 

 expanded in flight, in either case strongly suggest the 

 wings ol a wasp, or in some cases an ichneumon, 

 l^'urthermore, the eUtra are reduced in two different 

 wa\s — in some genera to linear rudiments more or less 

 broadened at their bases; in others to small subquadrate 

 or oval structures representing the bases alone. 



We thus find that wasps and allied forms are resembled 

 by species of many groups of insects, and the resemblance 

 is attained in all kinds of different ways. 



The numerous mimetic resemblances to the aggressive, 

 abundant, and well-defended ants supph' an even better 

 illustration. In the majoritx' of mimics the whole bod)- of 

 the mimetic form is moulded from ilie ancestral shape- 

 still exhibited by non-mimetic alHes — into that which is 

 characteristic of an ant. In some groups this means a 

 large amount of alteration, in others less. In this case, 

 too, the resemblance extends to forms which are alto- 

 gether outside the Insecta ; for many small species of 

 spiders closely mimic ants. In the famil\- of .-Iftidac 

 alone — and such resemblances occur in other families of 

 spiders — George W. and b^lizabeth G. Peckham state 

 that about a hundred ant-like species are known from 

 various parts of the world, and that the)' are ' very much 

 inore numerous in South America and in the Mala)- 

 Archipelago than in an)- other countries ',' viz. in the 

 very countries in which other examples of Mimicry are 

 especially abundant. The spider with its two-fold division 



* Occasional Papers of the Natural His/nry Socie/y of W'iscofisiv, vol. ii, 

 1892, Milwaukee ; see also a paper by ihe ^ame authors in vol. i, 1889. 



