We must remember, first, that disease is not necessarily evidence of unsoundness. Like some forms of moral obliquity, it may be merely evidence of a quality in the stock which renders it unable to tolerate a given environment. And this quality may be in itself an excellence of the most precious kind. This would be the true account of many cases of insanity, while others would be covered by the action of toxins on the brain. Heredity, we are told in many instances of "insanity," is more probably a heredity of "special liability to the production of toxins or to the action of toxins on the brain," than heredity of insanity proper. This view will naturally entail modifications in our methods of treating the "insane," as well as a considerable change in public opinion with regard to the significance of insanity. And, secondly, we must remember the importance of the environment, more especially of the human part of it. A man of sound stock is very commonly brought up as a sportsman, whose first idea is to kill; or as an idler, whose chief occupations are eating, drinking, and smoking, with travel and some amount of gambling thrown in by way of variety. Or he may easily be above all things a money-maker and a lover of money. His habits of this sort will determine to a very great extent the early--and that is the critical--environment of his children. The tendency in his family will be towards uniformity, towards one level, and that not a high level, of thought, activity, and character. His example and influence will go very far to counteract the advantages presumably ensured by the soundness of his stock. On the other hand, a man whose ancestry is eugenically not flawless may have such wide interests, so many and such fine powers, so much skill in different activities, and so high and generous a personal ideal, that the environment which his manner of life would make for his children--the inspiration he would be to them--might well be expected very largely, if not wholly, to counteract the disadvantages of defects in the stock. No doubt this principle should be applied with all reasonableness and care, but it is extremely important for the highest welfare, for the development of the best possibilities of the people, that it should be definitely recognised. ANTHROPOLOGY A BRANCH OF BIOLOGY