The Darwinian theory of the transmutation of species / examined by a graduate of the University of Cambridge.

  • Beverley, R. M. (Robert Mackenzie), 1797 or 1798-1868.
Date:
1867
Catalogue details

Licence: Public Domain Mark

Credit: The Darwinian theory of the transmutation of species / examined by a graduate of the University of Cambridge. Source: Wellcome Collection.

    401/408 (page 385)
    MIMICRY IN NATURE. From the Athenaeum. ‘ Oxford, Dec. 4, 1866. ‘ In every division of animated nature, even of comparatively limited extent, are to be found species which, although agreeing in all their chief structural characters with the types of such groups, exhibit in their ge- neral form and appearance so great a resemblance to the members of some other group, that by ordinary observers they are at once regarded as belonging to the latter, and not to their own legitimate group. Thus, an eel resembles a snake more than a fish, a cuckoo resembles a hawk, a humming-bird hawk-moth so nearly resembles a humming-bird that a person who had seen the Trochilidse in their American haunts could not be brought to believe that one of the moths which he happened to have noticed in Oxfordshire was an insect. This kind of external resemblance has been termed Analogy, and was greatly used by M‘Leay and Swainson in the development of their respective “ Systems of Nature.” More recently this resemblance has been termed “Mimicry,” and some very remarkable instances of it have been described and figured by Mr Bates, occurring in certain species of butterflies which frequent the banks of the river Amazon and other parts of South America in vast numbers, both of species and individuals, forming a separate family, the Iieli- coniidas, distinguished by their very peculiar elongated wings, as well as by their distinct styles of colouring. These butterflies are, it appears, ac- companied in their flight by certain other species of butterflies, which so closely resemble them in general form and colour as to be scarcely dis- tinguishable from them, although belonging to a totally different family, the Pieridm, of which our common white butterfly, Piens hrassicce, is the type. According to Mr Bates, the Ileliconians emit a disagreeable scent, which renders them distasteful to insectivorous birds, and so preserves them in the “battle of life and he moreover assumes that their mimics, the Pieridans, have, by a long process of development from the old typical white, broad-winged form of their own family, attained that of the well-to- do Heliconians, and have thereby been enabled to improve their condition and maintain their existence in nature. 2 5