disease and injury published by Brown-Séquard, Cossar Ewart, and many medical men are capable of an interpretation different to that which they have given.

Mr. Galton speaks as if the causes which have brought about the disappearance of most savage races when brought in contact with high civilization were obscure. I can assure him, however, that they have been worked out precisely and statistically by many medical observers on the spot. Apart from extermination by war, the only savage races which are disappearing are those of the New World, and in every instance they are perishing from the enormous mortality caused among them by introduced diseases against which their races have undergone no evolution. He will find these precise statistics in the tables of mortality issued by all the public health departments that exist in America, Polynesia, and Australasia. He will find also many accounts in the journals of travelers. If he will read the records of visits of parties of aborigines from the New World to the cities of Europe, he will find that their mortality, especially from consumption, was invariably high. There is nothing more mysterious about the disappearance of these races than there is about the disappearance of the dodo and the bison. They are perishing, not because, as Froude poetically puts it, they are like " caged eagles," incapable of domestication, but simply and solely because they are weak against certain diseases. If malaria instead of consumption were prevalent in cities, the English would be incapable of civilization, whereas the negroes and the wild tribes about the Amazon, and in New Guinea and Borneo, would be particularly capable of it. Indeed, it may be taken as a general rule, to which there is no exception, that every race throughout the world is resistant to every disease precisely in proportion to its past experience of it, and that only those races are capable of civilization which are resistant to the diseases of dense populations.

Before the voyage of Columbus, hardly a zymotic disease, with the exception of malaria, was known in the New World. The inhabitants of the Old World had slowly evolved against the diseases of civilized life under gradually worsening conditions, caused by the gradual increase of population, and therefore of disease. They introduced these maladies to the natives of the New World under the worst conditions then known. They built cities and towns, the natural breeding-places of all zymotic diseases, except those of the malarial type. They gave the natives clothes, which are the best vehicle for the transport of microbes. They endeavored to Christianize and civilize the natives, and so drew them into buildings where they were infected. They forced them to labor on plantations and in mines. In fact, they forced on them every facility for "catching disease. As a result, they exterminated or almost exterminated them. The natives of the Gilbert Islands lately petitioned our government not to permit missionaries to settle among them, as they feared destruction. They were perfectly right. Clothes and churches and schoolrooms are fatal to such people. The Tasmanians, before they were quite exterminated, had a saying that good people that is, people who went frequently to church. died young. They also were perfectly right—that is, as regards their own race. It is a highly significant fact that, whereas every white man's city in Asia or Africa has its native quarter, no white man's city in the New World has a native quarter. To find the pure aborigines of the New World we must go to parts remote from cities and towns. They cannot accomplish in a few generations an evolution which the natives of the Old World accomplished only after hundreds, perhaps thousands, of generations, and at the cost of millions of lives. The negroes, who were introduced into America to fill the void created by the disappearing aborigines, have perhaps persisted, but they had already undergone some evolution against consumption - the chief disease of civilization and much evolution against measles and other diseases. Yet even the negroes would not have persisted had they not been introduced under special conditions. They were taken to the warmer parts of America at a time when consumption was little rife as compared to its prevalence in the cities of Europe, and they were employed mainly in agricultural occupations. They had a special start, and were placed under conditions that worsened only slowly. As a result they underwent evolution, and are now able to persist in America. But African negroes,

as compared to the natives of the densely populated parts of Europe and Asia, have undergone little evolution against consumption. As a consequence, no African colony has ever succeeded in Europe or Asia. For instance, the Dutch and English imported about twelve thousand negroes into Ceylon a century ago. Within twenty years all had perished, mainly of consumption, and that in a country where the disease is not nearly so prevalent as in northern Europe, or the more settled parts of northern Asia.

There can be little doubt that the sterility of the New World races when brought into contact with civilization is due mainly to ill-health. The sterility of our upper classes is mainly voluntary. It is due to the possession of special knowledge. The growing sterility of the lower classes is due to the spread of that knowledge; hence the general and continuous fall in the birth-rate. Until we are able to estimate the part played by this knowledge it would be vain to collect statistics of comparative sterility.

We have frequently been told that no city family can persist for four generations unless fortified by country blood. That, I believe, is a complete error. Country blood does not strengthen city blood. It weakens it, for country blood has been less thoroughly purged of weak elements. It is true, owing to the large mortality in cities and the great immigration from the country, it is difficult to find a city family which has had no infusion of country blood for four generations. But to suppose on that account that country blood strengthens city blood against the special conditions of city life is to confuse post hoc with propter hoc.

Slum life and the other evil influences of civilization, including bad and insufficient food, vitiated air, and zymotic diseases, injure the individual. They make him acquire a bad set of traits. But they do not injure the hereditary tendencies of the race. Had they done so, civilization would have been impossible. Civilized man would have become extinct. On the contrary, by weeding out the unfittest, they make the race strong against those influences.

If, then, we wish to raise the standard of our race, we must do it in two ways. In the first place, we must improve the conditions under which the individual develops, and so make him a finer animal. In the second place, we must endeavor to restrict, as much as possible, the marriage of the physically and mentally unfit. In other words, we must attend both to the acquired characters and to inborn characters. By merely improving the conditions under which people live we shall improve the individual, but not the race. The same measures will not achieve both objects. Medical men have done a good deal for the improvement of the acquired characters of the individual by improving sanitation. They have attempted nothing toward the second object, the improvement of the inborn traits of the race. Nor will they atempt anything until they have acquired a precise knowledge of heredity from biologists. On the other hand, before biologists are able to influence medical men they must bring to bear their exact methods of thought on the great changes produced in various races by their experience, during thousands of years, of disease. I am sure our knowledge of heredity will gain in precision and breadth by a consideration of these tremendous, long-continued, and drastic experiments conducted by nature. No experiments conducted by man can compare with them in magnitude and completeness. And, as I have already intimated, the precise statistical information on which our conclusions may be based is already collected and tabulated. I am quite sure it is good neither for medicine nor biology that medical men and biologists should live as it were in separate and closed compartments, each body ignoring the splendid mass of data collected by the other. Much of medicine should be a part of biology, and much of biology a part of medicine.

EY W. LESLIE MACKENZIE, M.A., M.D.

It is to me a great privilege to be permitted to say something in any discussion where Dr. Francis Galton is leader; because from early in my student days until now I have felt that his method of handling sociological facts has always been at once scientific and practical. Whether the ideas he represents have had some subconscious effect in driving me into the public-health service,

I cannot tell; but since I entered that service fourteen years ago, I have been in a multitude of minor ways impressed with two things: first, that in every Scottish community, rural and urban, a hygienic renascence is in progress; second, that in the many forms it assumes, it has no explicit basis in scientific theory. In attempting, some time ago, to penetrate to the root-idea of the public-health movement, I concluded that, rightly or wrongly, we have all taken for granted certain postulates. The hygienic renascence is the objective side of a movement whose ethical basis is the set effort after a richer, cleaner, intenser, life in a highly organized society. The postulates of hygienics - whose administrative form constitutes the public-health service -are such as these: that society or the social group is essentially organic; that the social organism, being as yet but little integrated, is capable of rapid and easy modification, that is, of variations secured by selection; that disease is a name for certain maladaptations of the social organism or of its organic units; that diseases are thus, in greater or lesser degrees, preventable; that the prevention of disease promotes social evolution; that, by the organization of representative agencies - county councils, town councils, district councils, parish councils, and the like-the processes of natural selection may be indefinitely aided by artificial selections; that thus, by continuous modification of social organism, of its organic units, and of the compound environment of both, it is possible to further the production of better citizens more energetic, more alert, more versatile, more individuated. Provisionally, public health may be defined as the systematic application of scientific ideas to the extirpation of diseases and thereby to the direct or indirect establishment of beneficial variations both in the social organism and in its organic units. In more concrete form, it is an organized effort of the collective social energy to heighten the physiological normal of civilized living.

A science of hygienics might thus be regarded as almost equivalent to the science of cugenics; character is presupposed in both. The fundamental assumption of hygienics is that the human organism is capable of greater things than on the average it has anywhere shown, and that its potentialities can be elicited by the systematic improvement of the environment. From the practical side, hygienics aims at 'preparing a place" for the highest average of faculty to develop in.

Take heredity - one of Dr. Galton's points. The modern movement for the extirpation of tubercular phthisis began with the definite proof that the disease is due to a bacillus. But the movement did not become world-wide until the belief in the heredity of tuberculosis had been sapped. So long as the tubercular person was weighted by the superstition that tubercular parents must necessarily produce tubercular children, and that the parents of tubercular children must themselves have been tubercular, he had little motive to seek for cure, the fatalism being here supported by the alleged inheritance of disease. Now that he knows how to resist the invasion of a germ, he is proceeding in his multitudes to fortify himself. What is true of tuberculosis is true of many other infections. Consequently, every hygienist will agree with Dr. Galton that the dissemination of a true theory of heredity is of the first practical importance. Nor is the evil of a wrong theory of heredity confined to infectious disease. If the official "nomenclature of diseases" be carefully scrutinized, it will be found that the vast majority of diseases are due either to the attacks of infective or parasitic organisms, or to the functional stress of environment, which for this purpose is better named "nurture." This has recently been borne in upon me by the examination of school children. The conclusion inevitably arising out of the facts is that inherited capacities are in every class of society so masked by the effects of nurture, good or bad, that we have as yet no means of determining, in any individual case, how much is due to inheritance and how much to nurture. There is here an unlimited field for detailed study.

Next, fertility. It is, I suppose, on the whole, true that the less opulent classes are more fertile than the more opulent. But I am not prepared to accept the assumption that the economically upper classes" coincide with the biologically upper classes." May it not be that the relatively infertile ". upper classes (economical) are only the biological limit of the lower classes," from

which the 'upper' are continually recruited?

Until the economically lower classes are analyzed in such detail as will enable us to eliminate what is due to bad environment, we cannot come to final conclusions on the relative fertility or infertility of upper or "lower." Until such an analysis is made, we cannot well assume that the difference in fertility is in any degree due to fundamental biological differences or modifications. Dr. Noël Paton has recently shown that starved mothers produce starved offspring and that well-fed mothers produce well-fed offspring. In his particular experiment with guinea pigs the numbers of offspring were unaffected. If this experiment should be verified on the large scale, it would form some ground for doubting whether the mere increase of comfort directly produces biological infertility. The capacity to reproduce may remain; but reproduction may be limited by a different ethic. The universal fall in the birth-rate has been too rapid to justify simpliciter the conclusion that biological capacity has altered.

When the public-health organizations have succeeded in extirpating the grosser evils of environment, they will, it is hoped, proceed to deal more intimately with the individual. In the present movement for the medical examination and supervision of school children we have an indication of great developments. If to the relatively coarse methods of practical hygienics we could now add the precision of anthropometry, we should find ready to hand in the schools an unlimited quantity of raw material. We might even hope to add some

pages to the golden book " of thriving families." Incidentally, one might

suggest a minor inquiry: Of the large thriving families, do the older or the middle or the younger members show, on the average, the greater ultimate capacity for civic life? My impression is that, in our present social conditions, the middle children are likely to show the highest percentage of total capacity. This is a mere impression, but it is worth putting to the test of facts.

To the worker in the fighting line, as the public-health officer must always regard himself, Dr. Galton's suggestions come with inspiration and light.

BY G. BERNARD SHAW.

I agree with the paper, and go so far as to say that there is now no reasonable excuse for refusing to face the fact that nothing but a eugenic religion can save our civilization from the fate that has overtaken all previous civilizations.

It is worth pointing out that we never hesitate to carry out the negative side of eugenics with considerable zest, both on the scaffold and on the battlefield. We have never deliberately called a human being into existence for the sake of civilization; but we have wiped out millions. We kill a Tibetan regardless of expense, and in defiance of our religion, to clear the way to Lhassa for the Englishman; but we take no really scientific steps to secure that the Englishman when he gets there, will be able to live up to our assumption of his superiority. It is quite true, as the lecturer suggests, that the violent personal preferences on which most plays and novels are founded are practically negligible forces in society. They can be, and are, circumscribed by political and social institutions as successfully as the equally violent antipathies which lead to murder. In spite of all the romancers, men and women are amazingly indiscriminate and promiscuous in their attachments: they select their wives and husbands far less carefully than they select their cashiers and cooks. In the countries where they are not allowed to select at all, but have their marriages arranged for them wholly by their parents, the average result seems to be much the same as that of our own more promiscuous plan of letting people marry according to their fancies. In short, for all sociological purposes, it may safely be assumed that people are not particular as to whom they marry, provided they do not lose caste by the alliance. But we must not infer from this that they will tolerate any interference with their domestic life once they are married. Political marriages are perfectly practicable as far as the church door; but once the register is signed there is an end of all public considerations. If the selection is eugenically erroneous, there is no remedy. If it is so brilliantly successful that it seems a national loss to limit the husband's progenitive capacity to the breeding capacity of one woman, or the

wife's to an experiment with one father only, our marriage customs and prejudices will stand as sternly in the way as if no selection had been exercised at all in the first instance. Eugenics under such limitations lose their interest and relapse into mere Platonic speculation.

I am afraid we must make up our minds either to face a considerable shock to vulgar opinion in this matter or to let eugenics alone. Christianity began by attacking marriage; and though the attack utterly failed, the Catholic church still regards the marriage of a priest as an abomination. Luther would never have dared to marry a nun if his opinions on the question had not gone much farther than any Protestant community now dares to hint. But a merely negative attitude toward marriage is foredoomed to failure. Celibacy is so clearly an impossibilist doctrine that even St. Paul could not press it to its logical conclusion. Luther's views are anarchic, and suggest mere profligacy to the ordinary Philistine. Now, marriage is profligate enough in all conscience; but it is not anarchic. Consequently marriage holds its own in spite of the revulsions of the higher sexual conscience against the open claim of married people to be exempt from all social obligation and even self-respect in their relations with one another. And as this very licentiousness serves the all-important purpose of keeping the race recruited, it has never been possible to challenge it seriously until the popularization, about thirty-five years ago, of the sterilization of marriage. This practice had, for decency's sake, to justify itself as a eugenic one: it was said that when there were fewer children each child would receive more care and nourishment, and have a better chance of surviving to maturity. But a mere reduction in the severity of the struggle for existence is no substitute for positive steps for the improvement of such a deplorable piece of work as man. We may even allow, without countenancing for a moment the crudities of neoDarwinism, that it may conceivably do more harm than good. What we must fight for is freedom to breed the race without being hampered by the mass of irrelevant conditions implied in the institution of marriage. If our morality is attacked, we can carry the war into the enemy's country by reminding the public that the real objection to breeding by marriage is that marriage places no restraint on debauchery as long as it is monogamic, whereas eugenic breeding would effectually protect the mothers and fathers of the race from any abuse of their relations. As to the domestic and sympathetic function of marriage, or even its selfishly sexual function, we need not interfere with that. What we need is freedom for people who have never seen each other before, and never intend to see one another again, to produce children under certain definite public conditions, without loss of honor. That freedom once secured, and the conditions defined, we have nothing further to say in the matter until the necessarily distant time when the results of our alternative method of recruiting will be able to take the matter in hand themselves, and invite the world to reconsider its institutions in the light of experiments, which must, of course, in the meantime run concurrently with the promiscuity of ordinary marriage.

BY JOHN M. ROBERTSON.

1. A difficulty at once arises on the proposition that "the aim of eugenics is that each class or sect should be represented by its best specimens." What does this mean? Apparently (judging from the context) that the average of each recognizable type should be raised, that those who are now "best" should be the standard for the future averages. If that be the idea, the formula had better run simply: The aim of eugenics is to promote such calculation or choice in marriage as shall maximize the number of efficient individuals." There will always be some “best," and it is a contradiction in terms to say that they " represent their class."

2. It seems, again, an oversight to make a multiplication of "large and thriving families" the ostensible ideal. If all families were large," they certainly could not all be "thriving." A great increase of population would make thriving a harder matter; the struggle would be intensified on new lines. Further, thriving" is often a matter of the possession of unsocial or antisocial