. The descent of man, and selection in relation to sex. Evolution; Heredity; Human beings; Natural selection. CHAP. X.) COI,EOPTERA, 317 little point {a) ®n the head of the female Onitis furcifer, as well as on the head of the females of two or three allied species, is a rudimentary representative of the cephalic horn, which is common to the males of so many Lamellicorn beetles, as in PhancTeiis (fig. 18). ^ The old belief that rudiments have been created to complete the scheme of nature is here so far from holding good, that we have a complete inversion of the ordinary state of things in the
. The descent of man, and selection in relation to sex. Evolution; Heredity; Human beings; Natural selection. CHAP. X.) COI,EOPTERA, 317 little point {a) ®n the head of the female Onitis furcifer, as well as on the head of the females of two or three allied species, is a rudimentary representative of the cephalic horn, which is common to the males of so many Lamellicorn beetles, as in PhancTeiis (fig. 18). ^ The old belief that rudiments have been created to complete the scheme of nature is here so far from holding good, that we have a complete inversion of the ordinary state of things in the fanvily. We may reasonably suspect that the males originally bore horns and transferred them to the females in a rudimentary con- dition, as in so many other Lamellicorns. Why the males subse- quently lost their horns, we know not; but this may have been caused through the principle of compensation, owing to the de- velopment of the large horns and projections on the lower sur- face ; and as these are confined to the males, the rudiments of the upper horns on the females would not have been thus obliterated. The cases hitherto given refer to the Lamellicorns, but the males of some few other beetles, belonging to two widely dis- tinct groups, namely, the Curcuhonidae and Staphylinidse, are furnished with horns—in the former on the lower surface of the body,^ in the latter on the upper surface of the head and thorax. In the Staphylinidae the horns of the males are extraordinarily variable in the same species, just as we have seen with the Lamellicorns. In Siagonium we have a case of dimorphism, for the males can be divided into two sets, differing greatly in the size of their bodies and in the development of their horns, without intermediate gradations. In a species of Bledius ( 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 rese
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Keywords: ., bookcentury1800, bookdecade1870, booksubjecthumanbeings, bookyear
