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Show 260 DARWINISM CHAP. One of the characters by which some beetles are protected is excessive hardness of tho olytra and integuments. Soveml genera of weevils (Curculionidre) are t~us saved from attacl~, and these are often mimicked by species of softer and more f k Fro. 27. a. Doliops sp. (Longicorn) mimics P:whyrhynchns orbifn?, (b) (a hard curculio). c. Doliops cu'rculionoides miluics (cl) Pachyrhynchus sp. e. See past us pachyrhyuchoidcti (a grasshopper) mtmtcs (f) Apocyrtus sp. (a hn nl curculio). !I· Doliops sp. mimics (It) Par!tY:hynchus sp .. i. Phoraspis (gra. shopper) mtmtcs (k) a Coccmella. All the above are from the Philippines. The exact correspondence of ihe colour' of the ins cts themselves renders the mimicry much more complete in nature Ll•nn tl. appears in the above ligures. eatable groups. In South America, the genus Heilipus is one of these hard groups, and both Mr. Bates and M. Roolof:-;, a Belgian entomologist, have noticed that species of other genera exactly mimic them. So, in the Philippines, there IX WARNING COLORATION AND MIMICRY 261 is a group of Curculionidro, forming the genus Pachyrhynchus, in which all the species a,ro adorned with tho most brilliant metallic colours, banded and spotted in a curious manner, and are very smooth and hard. Other genera of Curculionidre (Desmidophorus, Alcidos), which are usually very differently coloured, have species in the Philippines which mimic the Pachyrhynchi ; and there arc also several longicorn beetles (Aprophata, Doliops, Acronia, and Agnia), which also mimic them. Besides these, there arc some longicorns and cetonias which reproduce the . ame colours and markings ; and there is even a cricket (Scepastus pachyrhynchoides ), which has taken on the form aml peculiar coloration of these 1 cctles in order to escape from enemic , which then avoid them as uneatable. 1 The figures on the opposite page exhibit . cvcral other examples of these mimicking insects. Innumerable other cases of mimicry occur among tropical insects ; but we must now pass on to consider a few of the very remarkable, but much rarer instances, that arc found among the higher animals. Minticry arnong the Vertebmt(£. Perhaps the most remarkable ca cs yet known are those of certain harmless snakes which mimic poisonous specie . The genus Elaps, in tropical America, consi. ts of poisonous . nakes which do not belong to the viper family (in which are included the rattlesnakes and most of tho c ·which arc poi onon. ), and which do not possess the broad tria,ngnlur head which characterises tho latter. They have a peculitLl' style of coloration, consisting of aJternate ring of red and bbck, or reel, black, and yellow, of different widths and groupell in Yarious ways in the different species; and it i. a, tylc of coloration which does not occur in any other group of snakes in the world. But in the same regions arc found three gencnt of harmless snakes, belonging to other families, som few pccie of which mimic the poisonous Ehtps, often o exactly that it il-:i with difficulty one ca,n be distingui heel from the other. Thus Elaps fulvius in Guatemala is imitated by the harmless Pliocerus equalis; Ehtps corallinus in Mexico is mimicked by tho 1 Compte-Rend1t de la Societe Entmnologique de B elgaue, series ii., No. 59, 1878. |