Darwin, with characteristic fairness, quotes some instances which appear to be opposed to the theory that the hen selects the most beautiful of her suitors. He informs us that Messrs Hewitt, Tegetmeier, and Brent, who have all had a long experience of domesticated birds, “do not believe that the females prefer certain males on account of the beauty of their plumage. . . . Mr Tegetmeier is convinced that a game-cock, though disfigured by being dubbed and with his hackles trimmed, would be accepted as readily as a male retaining all his natural ornaments. Mr Brent, however, admits that the beauty of the male probably aids in exciting the female; and her acquiescence is necessary. Mr Hewitt is convinced that the union is by no means left to mere chance, for the female almost invariably prefers the most vigorous, defiant, and mettlesome male”; and, in consequence, when there is a game-cock in the farmyard, the hens will all resort to him in preference to the cock of their own breed. Darwin thinks that “some allowance must be made for the artificial state in which these birds have long been kept,” and cites in his favour the case of Mr Cupples’ female deerhound that thrice produced puppies, and on each occasion showed a marked preference for one of the largest and handsomest, but not the most eager, of four deerhounds living with her, all in the prime of life. The question what is it that determines the choice of the female is obviously one of considerable importance, and it was to be expected that many zoologists would have conducted experiments with a view to deciding it. This legitimate expectation has not been realised. The matter of sexual selection remains to-day practically where Darwin left it. Wallace rejects the whole theory, and believes that natural selection alone can explain all the phenomena of sexual dimorphism. To such an extent does the enticing idea of the all-puissance of natural selection dominate the minds of scientific men that but few of them have paid any attention to the question of sexual selection. This neglect of the subject affords an example of the baneful results of the too-ready acceptance of an enticing theory, “Natural selection explains everything, why then investigate further?” seems to be the general attitude of our present-day naturalists. Edmund Selous and D. Dewar have made some observations on birds, and the Peckhams on spiders, in a state of nature. Such observations demonstrate that selective mating occurs in nature, but, for the most part, fail to show what it is that determines the choice.