. The descent of man, and selection in relation to sex. Evolution; Natural selection; Sexual selection in animals; Human beings -- Origin; Sexual dimorphism (Animals). Fig. 21.— Left-hand figure, male of Onitis fureifer, viewed laterally. Ri«ht-hand figure, female, a. Rudiment of cephalic horn. b. Trace of thoracic horn or crest. is a rudiment of a projection proper to the male, though entirely absent in the male of this particular species, is clear : for the female of JBubas bison (a form which comes next to Onitis) has a similar slight crest on the thorax, and the male has in the same situat
. The descent of man, and selection in relation to sex. Evolution; Natural selection; Sexual selection in animals; Human beings -- Origin; Sexual dimorphism (Animals). Fig. 21.— Left-hand figure, male of Onitis fureifer, viewed laterally. Ri«ht-hand figure, female, a. Rudiment of cephalic horn. b. Trace of thoracic horn or crest. is a rudiment of a projection proper to the male, though entirely absent in the male of this particular species, is clear : for the female of JBubas bison (a form which comes next to Onitis) has a similar slight crest on the thorax, and the male has in the same situation a great projection. So again there can be no doubt that the little point (a) on the head of the female Onitis fureifer, as well of the females of two or three allied species, is a rudimentary rej^resentative of the cephalic horn, which is common to the males of so many lamellicorn beetles, as in Phanseus, fig. 17. The males, indeed, of some unnamed beetles in the British Museum, which are believed actually to be- long to the genus Onitis, are furnished with a similar horn. The remarkable nature of this case will be best perceived by an illustration: the Ruminant quadrupeds run parallel with the lamellicorn beetles, in some females possessing horns as large as those of the male, in others having tjiem much smaller, or existing as mere rudiments (though this is as rare with ruminants as it is common. 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 Co.
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Keywords: ., boo, bookcentury1800, bookdecade1870, booksubjectnaturalselection
