half of the whole number of paupers are in institutions is to give a ridiculously low estimate; prisoners, 100,000, and several hundred thousand more that should be prisoners; juvenile delinquents, 23,000 in institutions; the number cared for by hospitals, dispensaries, "homes" of various kinds, in the year 1904 was in excess of 2,000,000. From these figures we get a rough total of nearly 3,000,000. Must we define a civilized and enlightened nation as one in which only one person in every thirty can be classed as defective or dependent?

It is needless to continue descriptions of this kind. The foregoing are representative data; they are published by the volume. It is always the same story—rapid increase of the unfit, defective, insane, criminal; slow increase, even decrease of the fit, normal, or gifted stocks. It is with such conditions in mind that Whetham writes: "Although this suppression of the best blood of the country is a new disease in modern Europe, it is an old story in the history of nations and has been the prelude to the ruin of states and the decline and fall of empires."

The ultimate aim of Sociology is doubtless the working out of the laws according to which stable communities are formed and maintained, and in which each component individual may enjoy and contribute the maximum of pleasure and profit. So the primary purpose of Statecraft is to produce a nation which shall be stable and enduring. This is all familiar ground. The objects of the nation's immediate activities and concern, protection from enemy, development of commerce and manufacture, agriculture, and education, all these are for the real purpose of establishing and promoting national integrity. No nation exists long without ideals and traditions, without teachers, artists, poets, and yet the primary condition of the existence of all these is a great body of citizens characterized by physical and mental soundness—vigor and sanity. In searching for guiding principles in their great endeavors the sociologist and statesman have sought aid from many sources. But, as Pearson points out, Philosophy has thus far given no law by the aid of which we can understand how a nation becomes physically and mentally vigorous. Anthropology has done little to show wherein exists human fitness as a social organism. Political Economists object that they are not listened to with respectful consideration in legislative chambers. History is the favorite hunting ground of the statesman searching for guidance; but unfortunately history teaches chiefly by example and analogy, rarely by true explanation. And just as some gifted persons are able to give an apt Biblical quotation touching any occurrence whatever, so, many statesmen can cite some historical analogue which they offer as evidence for their views, whatever they are. These men are sincere, in their ignorance of the nature of scientific proof. Finally, although the Statesman still holds rather aloof, the Sociologist comes now to the Biologist, inquiring whether by any chance he may be in possession of data or guiding principles which may be somehow of service in the building of stable societies. The Biologist does not send him away without contribution. The Sociologist makes known his needs, the Biologist displays his possessions, and it is at once evident to both that they have much in common, and that each is able to supply the other with some needed wares. Each may learn from the other; and best of all, the Biologist seems to have information which can be of the greatest service in their common work of building sound societies.

And the biologist is grateful to the sociologist for reminding him that he, too, has sacred duties in this direction. He is too often forgetful that the real aim of his own, as of any science, is to be useful in real human life. It is pleasing to the biologist to feel that he is at last in possession of facts of value to the student of human society, for to him his debt is great. From the sociologist he has drawn the inspirations which have led to some of his greatest discoveries. It was Malthus who suggested to Darwin the great principle of the struggle for existence among men which Darwin so successfully applied to other organisms, and used so profitably in building up his great theory of natural selection. It was from the sociologist that the biologist derived his idea of the physiological division of labor which has proved so fruitful a conception; and from the same source he has drawn many of his conceptions of organic individuality.

We might suggest here some of the topics upon which biology has information of value in this bio-social field; many of these we shall discuss later on from our present and special point of view. First of all come the facts regarding the variability and variation of human beings, not alone in physical characteristics, but in respect to psychic traits as well. Here as in all organisms we must distinguish between true variations and bodily modifications; that is, we must be careful to make, as far as possible, the biological distinction between innate and acquired traits, particularly in considering mental characteristics. Next must come consideration of the facts of heredity. This is undoubtedly the field of greatest importance to the Eugenist; facts of no other kind are of equal significance in determining the course of eugenic practice. We now have a fairly extensive working basis here from which to discuss heredity in man. The various phases of human selection should be noticed, in particular that known as selective fertility or differential fertility in different social groups or classes. Another evolutionary factor of importance here is that of "isolation" in the many and varied forms which it assumes in human society, especially those which result from assortative and preferential mating, and from the operation of social convention, restrictions in marriage, and the like.

Before discussing any of these subjects let us offer here just a word of caution to the enthusiast. The results gained in one field of science cannot be transferred in toto to another field and there be found to fit. Biology has learned much from Physics and Chemistry, but the biological applications of the laws of these sciences must be carried out with the greatest care. Such transference has often been premature and attended by results retardative to progress in the field of Biology. Any formula borrowed from one science and applied in another must be rigorously tested under the new conditions. The indiscriminating application of biological laws in the field of sociology may result in confusion and retardation in the progress of both sciences, or at any rate in their practical applications. As Thomson points out in writing on this topic, human society is not only a complex of individual activities of a strictly biological character, but also and further it involves an integration and regulation of those activities which are not yet, at least, susceptible of concrete biological analysis. Thomson says: "The biological ideal of a healthful, self-sustaining, evolving human breed is as fundamental as the social ideal of a harmoniously integrated society is supreme." The great danger here lies in forgetting the fundamental and general character of the biological principles. The ideals of biology and sociology need not coincide, often they do not, but they must not conflict. In practice Eugenics must be largely a social matter; but in its theory, its fundamentals, it must be largely biological.

The coming together of biology and sociology, and their common search for guiding principles in their common endeavor is likely