. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings; Sexual selection in animals; Sexual dimorphism (Animals); Sex differences. 494 THE DESCENT OF EAN. these ornaments should have been formed through the selec- tion of many successive variations, not one of which was originally intended to produce the ball-and-socket effect^ seems as incredible as that one of Eapheal's Madonnas should have been formed by the selection of chance daubs of paint made by a long ABC succession of young art- ists, not one of whom intended at first to draw the
. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings; Sexual selection in animals; Sexual dimorphism (Animals); Sex differences. 494 THE DESCENT OF EAN. these ornaments should have been formed through the selec- tion of many successive variations, not one of which was originally intended to produce the ball-and-socket effect^ seems as incredible as that one of Eapheal's Madonnas should have been formed by the selection of chance daubs of paint made by a long ABC succession of young art- ists, not one of whom intended at first to draw the human figure. In order to discover how the ocelli have been developed we cannot look to a long line of progenitors nor to many closely allied forms, for such do not now exist. But fortunately the several feathers on the wing suffice to give us a clew to the problem, and they prove to dem- onstration that a gra- dation is at least pos- sible from a mere spot to a finished ball-and- socket ocellus. The wing - feathers, bearing the ocelli, are covered with dark stripes (fig. 57) or with rows of dark spots (fig. 59), each stripe or Flff. 57. Part of secondary wing-feather of ^^^ ^f annfc rnnm'no- Argus pheasant, showing two perfect ocelli, ^^^. ^^ bpoib luiiuillg a and 6. A, B, C, D, etc., are dark stripes obliauelv down the running obliquely down, each to an ocellus, ^^ter side of the shaft' [Much of the web on both sides, especially t^ ^ ^^ ii^ ^ n* to the left of the shaft, has been cut off.] tO OUC 01 tne OCelll. The spots are gen- erally elongated in a line transverse to the row in which they stand. They often become confluent either in the line of the row—and then they form a longitudinal stripe—or transversely, that is, with the spots in the adjoining rows, and then thev form transverse stripes. A spot sometimes. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these
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Keywords: ., bookcentury1800, bookdecade1870, booksubjecthumanbeings, bookyear
