Many facts of great psychological significance have been deduced from these and similar observations of birds and quadrupeds in the rutting and pairing seasons. As Groos very pointedly remarks, in his work on the play-instinct of men and animals, if conscious selection may be disputed in these amorous displays, unconscious selection, to the extent at least that "the female is most easily won by the male who most strongly excites her sexual instinct," is scarcely open to doubt.
Whether it be the midnight song of the musical tomcat or the canso of the troubadour: the zrowl of a iealous dog or the mighty deeds of the Homeric heroes; all have a love-origin, a sexual fountain-head, and are but means in the vast workshop of nature for the evolution of that great law of natural selection which Darwin so ably defined.1
Mutually desirable sexual conjunction has always been, both in men and animals, an end involving considerable difficulty and struggle. The doe will race for miles to escape from an undesirable buck, and birds win the favor of their lady-loves by a long stage of the most assiduous courtship. We ourselves may obtain other women; indeed, by some tantalizing diabolism of fate, the more keenly we pursue the only one, the more persistently do the others fling themselves at us; but the perfect union, that which satisfies every want and longing of our nature, which conforms more nearly to every requirement of the selective law, is a matter sometimes involving years of our best physical or intellectual effort. And this is a wise ordination, spurring both men and women to the very highest exercise of their mental and physical powers; and that at a period of life when both are in their prime; thus accomplishing, as I have previously pointed out, purposes for the betterment of mankind which might otherwise have remained unfulfilled.
Among savages, and indeed largely in civilization, as we have seen, force is the symbol of virility, as courage is its psychic manifestation. Violence is a qualification of the first order in the prosecution of a love-suit. And this is only natural. Men are violent, pugnacious, lavish of their physical and mental energies, only when they are deeply in earnest; when they properly appreciate the prize for which they struggle; and the object of such a passion has no means of gauging its earnestness save by the energies called into play in the effort to gratify it. The instinct of modesty, which, in its primordial form, manifests itself in resistance, active or passive, is all woman has to oppose this passion; and it needs no words to show that modesty yields, as does everything else, easier to force than to feebleness, bo that the woman violates no law of nature in yielding to the most vigorous of her wooers.3
1 It may t>c remarked here that sexual selection as a law was taken up by Groos at about the point where "The Descent of Man" left it, considerably enriched by that maRnificent reasoner, and carried forward by more recent writers to the logical conclusion, first hinted at by Hacckel, that sexual selection is a part, and not a small one, nf rmtiir'il m»lr.nfinTi