. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings. Chap. XIV.] GRADATION OF CHARACTER. 137 toward the left-hand upper corner, the feather being held erect, in the position a b c in which it is here drawn. Beneath this thickened part there is on the surface of the ball an oblique almost pure-white mark which shades off downward into a pale-leaden hue, and this into yellow- ish and brown tints, which insensibly be- come darker and dark- er toward the lower part of the ball. It is th
. The descent of man, and selection in relation to sex. Evolution (Biology); Sexual selection in animals; Sexual dimorphism (Animals); Sex differences; Human beings. Chap. XIV.] GRADATION OF CHARACTER. 137 toward the left-hand upper corner, the feather being held erect, in the position a b c in which it is here drawn. Beneath this thickened part there is on the surface of the ball an oblique almost pure-white mark which shades off downward into a pale-leaden hue, and this into yellow- ish and brown tints, which insensibly be- come darker and dark- er toward the lower part of the ball. It is this shading, which gives so admirably the effect of light shining on a convex surface. If one of the balls be examined, it will be seen that the lower part is of a browner tint nnd U indiv;i Inetlv Fia- 56.—Part of Secondary wing-feather of tint anci is indistinctly ArffUg pheaBant showing twoTa and ©, per- «or»intofl hv a mirvod ,r('1 ocelli. A. B, 0, etc., 'lark BtrlpeB run- scparatea ny a curved ning oblIquely (1()WI1_ ,,„.,, „, M oeStta: oblique line from the [Much of the webon both sides, especially to ^ 1. , . the left of the shaft, has been cut off]. upper part, winch is yellower and more leaden; this oblique line runs at right angles to tTie longer iixis of the white patch of Light, and indeed of :ill the shading; but this diflcrcncc in the tints, which cannot of course be shown in the woodcut, docs not in the least interfere with the perfect shading of the ' *H When the Argus pheasant displays bis wing-feathers Ukeiffraal fan, those nearest to the body stand more upright than the outer ones,. 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: D. Appleton and Company
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