. The descent of man, and selection in relation to sex. Evolution; Heredity; Human beings; Natural selection. CHAP. XIV. ] BIRDS— GRADA TION OF CHARA CTERS. 451 of sliglitly different iridescent shades. A trifling character in the disk deserves notice ; the barbs, for a space along one of the concentric zones, are more or less destitute of their barbules, so that a part of the disk is surrounded by an almost transparent zone, which gives it a highly finished aspect. But I have else- where described =^ an exactly analogous variation in the hackles of a sub-variety of the game-cock, in which the
. The descent of man, and selection in relation to sex. Evolution; Heredity; Human beings; Natural selection. CHAP. XIV. ] BIRDS— GRADA TION OF CHARA CTERS. 451 of sliglitly different iridescent shades. A trifling character in the disk deserves notice ; the barbs, for a space along one of the concentric zones, are more or less destitute of their barbules, so that a part of the disk is surrounded by an almost transparent zone, which gives it a highly finished aspect. But I have else- where described =^ an exactly analogous variation in the hackles of a sub-variety of the game-cock, in which the tips, having a. 8"iG. 54.—Feather of Peacock, about two-thirds of natural size, drawn by Mr. Ford. The transparent zone is represented by the outermost white zone, confined to the upper end of the disk. metallic lustre, ''are separated from the lower part of the feather by a symmetrically shaped transparent zone, composed of the naked portions of the barbs.'' The lower margin or base of the dark-blue centre of the ocellus is deeply indented on the line of the shaft. The surrounding zones likewise show traces, as may be seen in the drawing (fig. 54), of indentations, or Wither breaks. These indentations are common to the Indian •• "Variation af Animals and Plants under Domestication," voL i. p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Darwin, Charles, 1809-1882. New York Hurst
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Keywords: ., bookcentury1800, bookdecade1870, booksubjecthumanbeings, bookyear
