. The descent of man, and selection in relation to sex. Evolution; Natural selection; Sexual selection in animals; Human beings -- Origin; Sexual dimorphism (Animals). 133 SEXUAL SELECTION: BIRDS. [Part II. It should be particularly observed that each ocellus stands in obvious connection with a dark stripe, or row of dark spots, for both occur indifferently on the same feather. Thus in Fig. 56 stripe A runs to ocellus a y B runs to ocellus b ; stripe C is broken in the upper part and runs down to the next succeeding ocellus, not represented in the wood- cut ; D to the next lower one, and so wi
. The descent of man, and selection in relation to sex. Evolution; Natural selection; Sexual selection in animals; Human beings -- Origin; Sexual dimorphism (Animals). 133 SEXUAL SELECTION: BIRDS. [Part II. It should be particularly observed that each ocellus stands in obvious connection with a dark stripe, or row of dark spots, for both occur indifferently on the same feather. Thus in Fig. 56 stripe A runs to ocellus a y B runs to ocellus b ; stripe C is broken in the upper part and runs down to the next succeeding ocellus, not represented in the wood- cut ; D to the next lower one, and so with the stripes E and F. Lastly, the several ocelli are separated from each oth- er by a pale surface bearing irregular black marks. I will next describe the other extreme of the series, namely, the first trace of an ocellus. The short secondary wing- feather (Fig. 51), nearest to the body, is marked, like the other feathers, with oblique, longitudi- nal, rather irregular, rows of spots. The lowest spot, or that nearest the shaft, in the five lower rows (ex- cluding the basal row) is a little larger than the other spots in the same so that the shading of the ball-and-socket ocelli ought to be slightly different on the different feathers, in order to bring out their full effect, relatively to the incidence of the light. Mr. T. W. Wood, who has the experienced eye of an artist, asserts ('Field,' newspaper, May 28, 18*70, p. 457) that this is the case; but after carefully examining two mounted specimens (the proper feathers from one having been given to me by Mr. Gould for more accurate comparison) I cannot perceive that this acme of perfection in the shading has been attained; nor can others to whom I have shown these feathers recognize the Fig. 57.—Basal part of the Secondary ' wing-feather, nearest to tbe 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: ., boo, bookcentury1800, bookdecade1870, booksubjectnaturalselection
