. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings. S9» The Descent of Man, Part II. species of the genus, are furnished with singular projections on their anterior femora, and with a great fork or pair of horns on the lower surface of the thorax. Judging from other insects, these may aid the male in clinging to the female. Although the males have not even a trace of a horn on the upper surface of the body, yet the fe- males plainly exhibit a rudiment of a single horn on the head (fig. 22, a), and of a crest (b) on the thorax. That the
. The descent of man, and selection in relation to sex. Evolution; Natural selection; Heredity; Human beings. S9» The Descent of Man, Part II. species of the genus, are furnished with singular projections on their anterior femora, and with a great fork or pair of horns on the lower surface of the thorax. Judging from other insects, these may aid the male in clinging to the female. Although the males have not even a trace of a horn on the upper surface of the body, yet the fe- males plainly exhibit a rudiment of a single horn on the head (fig. 22, a), and of a crest (b) on the thorax. That the slight thoracic «£ V >S cres* *n ^e ^ema^e *s a rudiment of a pro- T* * ' jection proper to the male, though entirely absent in the male of this particular species, is clear: for the female of Bubas bison (a genus which comes next to Onitis) has a similar slight crest on the thorax, and the male bears a great projection in the same situation. So, again, there can hardly be a doubt that the little point (a) on the head of the female Onitis. Fig 21. Onitis furcifer, male viewed from be- 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. London, J. Murray
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Keywords: ., bookcentury1800, bookdecade1890, booksubjecthumanbeings, bookyear
