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Show 272 THE PUINCIPLES OF PAnT II. from each other in external appearance, it is the male which, with rare exceptions, has been chiefly modified; for the female still remains more like the young of her own species, and more like the other members of the same group. The cause of this seems to lie in the males of almost all animals having stronger passions than the females. Hence it is the males that fight together and sedulously display their charms before the females ; and those which are victorious transmit their superiority to their male offspring. vVhy the males do not transmit their characters to both sexes will hereafter be considered. That the males of aU mammals eagerly pursue the females is notorious to every one. So it is with birds; but many male birds do not so much pursue the female, as display their plumage, perform strange antics, and pour forth their song, in her presence. vVith the few fish which have been observed, the male seems much more eager than the female; and so it is with alligators, and apparently with Batrachians. Throughout the enormous class of insects, as Kirby remarks,11 "the law is, that the male " shall seek the female." With spiders and crustaceans, as I hear from two great authorities, J\'Ir. Blackwall and M1·. 0. Spence Bate, the males are more active and more erratic in their habits than the females. With insects and crustaceans, when the organs of sense or locomotion are present in the one sex and absent in the other, or when, as is frequently the case, they are more highly developed in the one than the other, it is almost invariably the male, as far as I can discover, which retains such organs, or has them most developed ; and this shews that the male is the more active member in the courtship of the sexes.12 11 Kirby and Spence, 'Introduction to Entomology,' vol. iii. 1826, p. 342. 12 One parasitic Hymenopterous insect (West wood, ' Modern Class. of Insects,' vol. ii. p. 160) fo1·ms an exception to the rule, as the male CHAP. VIII. SEXUAL SELECTION. 273 . Th~ female, on the other hand, with the rarest exception, IS less eager than the male. As the illustrious Hunter 13 long ago observed, she generally "requires to H be courted ; " she is coy, and may often be seen endeavouring for a long time to escape from the male. Every one who has attended to the habits of animals will be able to call to mind instances of this kind. Judging from various facts, hereafter to be given, and from the results which may fairly be attributed to sexu.al selection, the female, though comparatively passive, generally exerts some choice and accepts one male in preference to others. Or she may accept, as appearances would sometimes lead us to believe, not the male which is the most attractive to her but the one which is the least distasteful. The e:x~rtion of some choice on the part of the female seems almost as general a law as the eagerness of the male. V\T e are naturally led to enquire why the male in so many and such widely distinct classes has been rendered more eager than the female, so that he searches for her and plays the more active part in courtshjp, .It would be no advantage and some loss of power if both sexes were mutually to search for each other; but why should the male almost always be the seeker? With plants, the ovules after fertilisation have to be nourjshed for a time; hence the pollen is necessarily brought to the female organs-bejno- placed on the +' h 0 Sdgma, t rough the agency of insects or of the wind, has. rudimentary wings, and never quits the cell in which it is born, whilst the fem~le has well-developed wings. Audouin believes that the fe~ules are Impregnated by the males which are born in the same cells With them ; but it is much more probable that the females vi::;it other c~lls, and thus avoid close interbreeding. We shall hereafter meet w~th a few exceptional cases, in various classes, in which the fBmale, mstead of the male, is the seeker and wooer. 13 'Essays nnd Observations,' edited by Owen, vol. i. 1861, p. IS~. VOL. I. T |