Archive image from page 309 of The descent of man . The descent of man : and selection in relation to sex descentofmanseledarw Year: 1874 296 THE DESCENT OF MAN. scheme of nature is here ro far from holding good, that we have a complete inversion of the ordinary state of things in the family. We may reasonably suspect that the males originally bore horns and transferred them to the females in a rudimentary condition, as in so many other Lamellicorns. Why the males subsequently lost their horns, we know not; but this may have been caused through the principle of compensation, owing to the deve
Archive image from page 309 of The descent of man . The descent of man : and selection in relation to sex descentofmanseledarw Year: 1874 296 THE DESCENT OF MAN. scheme of nature is here ro far from holding good, that we have a complete inversion of the ordinary state of things in the family. We may reasonably suspect that the males originally bore horns and transferred them to the females in a rudimentary condition, as in so many other Lamellicorns. Why the males subsequently lost their horns, we know not; but this may have been caused through the principle of compensation, owing to the development of the large horns and projections on the lower surface; 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 distinct groups, namely, the Curculionidse and Staphylinidae, 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 Staphy- linidse, 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 bodfes and in the development of their horns, without intermediate gradations. In a species of Bledius (fig. 23), also belonging to the
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