The descent of man, and selection in relation to sex . know the steps by which thesewonderfully-beautiful and complex ornaments have beendeveloped, the process at least with insects has probablybeen a simple one; for, as Mr. Trimen writes to me,no characters of mere marking or coloration are so unstable in the Lepidoptera as the ocelli, both in number and size. Mr. Wallace, who first called myattention to this subject, shewed me a series of speci-mens of our common meadow-brown butterfly {Hip- ^?^ Bechsteiu, Naturgeschichte Deutschlands, B. iv. 1795, s. 31, ona sub-variety of the Monck pigeoa.
The descent of man, and selection in relation to sex . know the steps by which thesewonderfully-beautiful and complex ornaments have beendeveloped, the process at least with insects has probablybeen a simple one; for, as Mr. Trimen writes to me,no characters of mere marking or coloration are so unstable in the Lepidoptera as the ocelli, both in number and size. Mr. Wallace, who first called myattention to this subject, shewed me a series of speci-mens of our common meadow-brown butterfly {Hip- ^?^ Bechsteiu, Naturgeschichte Deutschlands, B. iv. 1795, s. 31, ona sub-variety of the Monck pigeoa. Chap. XIV, OCELLI. 1 oo oo jparchia Janira) exhibiting numerous gradations froma simple minute black spot to an elegantly-sbadedocellus. In a S. African butterfly (Cyllo Leda, Linn.)belonofinfr to the same familv, the ocelli are even stillmore variable. In some specimens (A, fig. 52) largespaces on the upper surface of the wings are colouredblack, and include irregular white marks; and fromthis state a complete gradation can be traced into a A AI. Fig. 52. Cyllo leda, Linn., from a drawing by Mr. Trinien, shewing the extreme range of variation in the ocelli. A. Specimen, from Mauritius, upper surface of Specimen, from Natal, ditto. B. Specimen, from Java, upper surface of Specimen, from Mauritius, ditto. tolerably perfect (A^) ocellus, and this results from thecontraction of the irregular blotches of colour. Inanother series of specimens a graclation can be followedfrom excessively minute white dots, surrounded by ascarcely visible black line (B), into perfectly symme-trical and large ocelli (B^).^^ In cases like these, the ?i^ This woodcut lias been engraved from a beautiful drawing, mostkiudly made for me by Mr. Trimen ; see also his description of the i 34 SEXUAL SELECTION : BIRDS. Part IL development of a perfect ocellus does not require along course of variation and selection. With birds and many other animals it seems, fromthe comparison of al
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Keywords: ., boo, bookcentury1800, bookdecade1870, booksubjectnaturalselection
