The methods of artificial selection are either negative, which restrain the unfit from propagating, or positive, which encourage the fit to propagate. The most radical negative method is mutilation, and is employed by man with the lower animals and with slaves, but this plan could hardly be used by civilised society for human breeding. Imprisonment temporarily restrains some classes of society from perpetuating themselves. Prevention of conception is at present mostly a voluntary means, but accomplishes the elimination of both fit and unfit. Celibacy of monk and nun, of bachelor and maid, works also in both directions. In many indirect ways society discourages from marriage those whom it supposes to be unfit as tested by wealth, rank, or birth. It is not, however, so much by the extension of any negative methods, but rather by positive means that artificial selection may be best employed. I will mention three forms by which human breeding might be materially advanced. By common law and custom the wife surrenders herself physically to submit and morally to obey the husband. This is not for the most part harshly and literally carried out in civilised countries; still there is a vast deal of oppression which is hidden from all eyes, and which is often passively received by women as her rightful lot. This again is a subject upon which delicacy—perhaps unwise—forbids free discussion, but its bearing is manifest. If women have the choice to bear or not to bear, and she with educated conscience choose by fitness of offspring, a large and powerful element of artificial selection may be introduced. Again all governments have laws concerning marriage which act in general toward encouraging the fit. Certain conditions as to age, etc., being fulfilled, the state grants a marriage licence, and public opinion might easily be led to make the requirements more stringent. As a physician has suggested to me a certificate of health from an approved medical examiner might be required of all applicants for legal marriage. This would certainly be a strong measure of artificial selection, and would save much misery springing from ignorance and vice. It surely seems scarcely fitting that those who cannot pass an examination for life insurance freely contract marriage with view to issue.