Chapter XX

EUGENICS AND EUTHENICS

Emphasis has been given, in several of the foregoing chapters, to the desirability of inheriting a good constitution and a high degree of vigor and disease-resistance. It has been asserted that no measures of hygiene and sanitation can take the place of such inheritance. It is now desirable to ascertain the limits within which good inheritance is effective, and this may be conveniently done by a study of the lives of a group of people who inherited exceptionally strong physical constitutions.

The people referred to are taken from a collection of histories of long life made by the Genealogical Record Office of Washington. One hundred individuals were picked out at random, each of whom had died at the age of 90 or more, and with the record of each individual were placed those of all his brothers and sisters. Any family was rejected in which there was a record of wholly accidental death (e.g., families of which a member had been killed in the Civil War). The 100 families, or more correctly fraternities or sibships, were classified by the number of children per fraternity, as follows:

Number of Total number Number of children per of children fraternities fraternity in group

The average at death of these 669 persons was 64.7 years. The child mortality (first 4 years of life) was 7.5% of the total mortality, 69 families showing no deaths of that kind. The group is as a whole, therefore, long-lived.

The problem was to measure the resemblance between brothers and sisters in respect of longevity,--to find whether knowledge of the age at which one died would justify a prediction as to the age at death of the others,--or technically, it was to measure the fraternal correlation of longevity. A zero coefficient here would show that there is no association; that from the age at which one dies, nothing whatever can be predicted as to the age at which the others will die. Since it is known that heredity is a large factor in longevity, such a finding would mean that all deaths were due to some accident which made the inheritance of no account.

In an ordinary population it has been found that the age at death of brothers and sisters furnishes a coefficient of correlation of the order of .3, which shows that heredity does determine the age at which one shall die to considerable extent, but not absolutely.

The index of correlation between the lengths of life within the fraternity in these 100 selected families, furnished a coefficient of-.0163+-.0672, practically zero. In other words, if the age is known at which a member of one of these families died, whether it be one month or 100 years, nothing whatever can be predicted about the age at which his brothers and sisters died.

Remembering that longevity is in general inherited, and that it is found in the families of all the people of this study (since one in each fraternity lived to be 90 or over) how is one to interpret this zero coefficient? Evidently it means that although these people had inherited a high degree of longevity, their deaths were brought about by causes which prevented the heredity from getting full expression. As far as hereditary potentialities are concerned, it can be said that all their deaths were due to accident, using that word in a broad sense to include all non-selective deaths by disease. If they had all been able to get the full benefit of their heredity, it would appear that each of these persons might have lived to 90 or more, as did the one in each family who was recorded by the Genealogical Record Office. Genetically, these other deaths may be spoken of as premature.

In an ordinary population, the age of death is determined to the extent of probably 50% by heredity. In this selected long-lived population, heredity appears not to be responsible in any measurable degree whatsoever for the differences in age at death.

The result may be expressed in another, and perhaps more striking, way. Of the 669 individuals studied, a hundred--namely, one child in each family--lived beyond 90; and there were a few others who did. But some 550 of the group, though they had inherited the potentiality of reaching the average age of 90, actually died somewhere around 60; they failed by at least one-third to live up to the promise of their inheritance. If we were to generalize from this single case, we would have to say that five-sixths of the population does not make the most of its physical inheritance.

This is certainly a fact that discourages fatalistic optimism. The man who tells himself that, because of his magnificent inherited constitution, he can safely take any risk, is pretty sure to take too many risks and meet with a non-selective--i.e., genetically, a premature--death, when he might in the nature of things have lived almost a generation longer.

It should be remarked that most of the members of this group seem to have lived in a hard environment. They appear to belong predominantly to the lower strata of society; many of them are immigrants and only a very few of them, to judge by a cursory inspection of the records, possessed more than moderate means. This necessitated a frugal and industrious life which in many ways was doubtless favorable to longevity but which may often have led to overexposure, overwork, lack of proper medical treatment, or other causes of a non-selective death. We would not push the conclusion too far, but we can not doubt that this investigation shows the folly of ignoring the environment,--shows that the best inherited constitution must have a fair chance. And what has here been found for a physical character, would probably hold good in even greater degree for a mental character. All that man inherits is the capacity to develop along a certain line under the influence of proper stimuli,--food and exercise. The object of eugenics is to see that the inherent capacity is there. Given that, the educational system is next needed to furnish the stimuli. The consistent eugenist is therefore an ardent euthenist. He not only works for a better human stock but, because he does not want to see his efforts wasted, he always works to provide the best possible environment for this better stock.

In so far, then, as euthenics is actually providing man with more favorable surroundings,--not with ostensibly more favorable surroundings which, in reality, are unfavorable--there can be no antagonism between it and eugenics. Eugenics is, in fact, a prerequisite of euthenics, for it is only the capable and altruistic man who can contribute to social progress; and such a man can only be produced through eugenics.

Eugenic fatalism, a blind faith in the omnipotence of heredity regardless of the surroundings in which it is placed, has been shown by the study of long-lived families to be unjustified. It was found that even those who inherited exceptional longevity usually did not live as long as their inheritance gave them the right to expect. If they had had more euthenics, they should have lived longer.

But this illustration certainly gives no ground for a belief that euthenics is sufficient to prolong one's life beyond the inherited limit. A study of these long-lived families from another point of view will reveal that heredity is the primary factor and that good environment, euthenics, is the secondary one.

For this purpose we augment the 100 families of the preceding section by the addition of 240 more families like them, and we examine each family history to find how many of the children died before completing the fourth year of life. The data are summarized in the following table:

CHILD MORTALITY IN FAMILIES OF LONG-LIVED STOCK, GENEALOGICAL RECORD OFFICE DATA

Size of No. of families No. of families Total no. family investigated showing deaths of deaths under 5 years

The addition of the new families (which were not subjected to any different selection than the first 100) has brought down the child mortality rate. For the first 100, it was found to be 7.5%. If in the above table the number of child deaths, 119, be divided by the total number of children represented, 2,259, the child mortality rate for this population is found to be 5.27%, or 53 per thousand.

The smallness of this figure may be seen by comparison with the statistics of the registration area, U. S. Census of 1880, when the child mortality (0-4 years) was 400 per thousand, as calculated by Alexander Graham Bell. A mortality of 53 for the first four years of life is smaller than any district known in the United States, even to-day, can show for the first year of life alone. If any city could bring the deaths of babies during their first twelve months down to 53 per 1,000, it would think it had achieved the impossible; but here is a population in which 53 per 1,000 covers the deaths, not only of the fatal first 12 months, but of the following three years in addition.

Now this population with an unprecedentedly low rate of child mortality is not one which had had the benefit of any Baby Saving Campaign, nor even the knowledge of modern science. Its mothers were mostly poor, many of them ignorant; they lived frequently under conditions of hardship; they were peasants and pioneers. Their babies grew up without doctors, without pasteurized milk, without ice, without many sanitary precautions, usually on rough food. But they had one advantage which no amount of applied science can give after birth--namely, good heredity. They had inherited exceptionally good constitutions.

It is not by accident that inherited longevity in a family is associated with low mortality of its children. The connection between the two facts was first discovered by Mary Beeton and Karl Pearson in their pioneer work on the inheritance of duration of life. They found that high infant mortality was associated with early death of parents, while the offspring of long-lived parents showed few deaths in childhood. The correlation of the two facts was quite regular, as will be evident from a glance at the following tables prepared by A. Ploetz:

LENGTH OF LIFE OF MOTHERS AND CHILD-MORTALITY OF THEIR DAUGHTERS. ENGLISH QUAKER FAMILIES, DATA OF BEETON AND PEARSON, ARRANGED BY PLOETZ

LENGTH OF LIFE OF FATHERS AND CHILD-MORTALITY OF THEIR DAUGHTERS

To save space, we do not show the relation between parent and son; it is similar to that of parent and daughter which is shown in the preceding tables. In making comparison with the 340 families from the Genealogical Record Office, above studied, it must be noted that Dr. Ploetz' tables include one year longer in the period of child mortality, being computed for the first five years of life instead of the first four. His percentages would therefore be somewhat lower if computed on the basis used in the American work.

These various data demonstrate the existence of a considerable correlation between short life (brachybioty, Karl Pearson calls it) in parent and short life in offspring. Not only is the tendency to live long inherited, but the tendency not to live long is likewise inherited.

But perhaps the reader may think they show nothing of the sort. He may fancy that the early death of a parent left the child without sufficient care, and that neglect, poverty, or some other factor of euthenics brought about the child's death. Perhaps it lacked a mother's loving attention, or perhaps the father's death removed the wage-earner of the family and the child thenceforth lacked the necessities of life.

Dr. Ploetz has pointed out that this objection is not valid, because the influence of the parent's death is seen to hold good even to the point where the child was too old to require any assistance. If the facts applied only to cases of early death, the supposed objection might be weighty, but the correlation exists from one end of the age-scale to the other. It is not credible that a child is going to be deprived of any necessary maternal care when its mother dies at the age of 69; the child herself was probably married long before the death of the mother. Nor is it credible that the death of the father takes bread from the child's mouth, leaving it to starve to death in the absence of a pension for widowed mothers, if the father died at 83, when the "child" herself was getting to be an old woman. The early death of a parent may occasionally bring about the child's death for a reason wholly unconnected with heredity, but the facts just pointed out show that such cases are exceptional. The steady association of the child death-rate and parent death-rate at all ages demonstrates that heredity is a common cause.

But the reader may suspect another fallacy. The cause of this association is really environmental, he may think, and the same poverty or squalor which causes the child to die early may cause the parent to die early. They may both be of healthy, long-lived stock, but forced to live in a pestiferous slum which cuts both of them off prematurely and thereby creates a spurious correlation in the statistics.

We can dispose of this objection most effectively by bringing in new evidence. It will probably be admitted that in the royal families of Europe, the environment is as good as knowledge and wealth can make it. No child dies for lack of plenty of food and the best medical care, even if his father or mother died young. And the members of this caste are not exposed to any such unsanitary conditions, or such economic pressure as could possibly cause both parent and child to die prematurely. If the association between longevity of parent and child mortality holds for the royal families of Europe and their princely relatives, it can hardly be regarded as anything but the effect of heredity,--of the inheritance of a certain type of constitution.

Dr. Ploetz studied the deaths of 3,210 children in European royalty, from this viewpoint. The following table shows the relation between father and child:

LENGTH OF LIFE OF FATHERS AND CHILD-MORTALITY OF THEIR CHILDREN IN ROYAL AND PRINCELY FAMILIES, PLOETZ' DATA

Allowing for the smallness of some of the groups, it is evident that the amount of correlation is about the same here as among the English Quakers of the Beeton-Pearson investigation, whose mortality was shown in the two preceding tables. In the healthiest group from the royal families--the cases in which the father lived to old age--the amount of child mortality is about the same as that of the Hyde family in America, which Alexander Graham Bell has studied--namely, somewhere around 250 per 1,000. One may infer that the royal families are rather below par in soundness of constitution.

All these studies agree perfectly in showing that the amount of child mortality is determined primarily by the physical constitution of the parents, as measured by their longevity. In the light of these facts, the nature of the extraordinarily low child mortality shown in the 340 families from the Genealogical Record Office, with which we began the study of this point, can hardly be misunderstood. These families have the best inherited constitution possible and the other studies cited would make us certain of finding a low child mortality among them, even if we had not directly investigated the facts.

If the interpretation which we have given is correct, the conclusion is inevitable that child mortality is primarily a problem of eugenics, and that all other factors are secondary. There is found to be no warrant for the statement so often repeated in one form or another, that "the fundamental cause of the excessive rate of infant mortality in industrial communities is poverty, inadequate incomes, and low standards of living." Royalty and its princely relatives are not characterized by a low standard of living, and yet the child mortality among them is very high--somewhere around 400 per 1,000, in cases where a parent died young. If poverty is responsible in the one case, it must be in the other--which is absurd. Or else the logical absurdity is involved of inventing one cause to explain an effect to-day and a wholly different cause to explain the same effect to-morrow. This is unjustifiable in any case, and it is particularly so when the single cause that explains both cases is so evident. If weak heredity causes high mortality in the royal families, why, similarly, can not weak heredity cause high infant mortality in the industrial communities? We believe it does account for much of it, and that the inadequate income and low standard of living are largely the consequences of inferior heredity, mental as well as physical. The parents in the Genealogical Record Office files had, many of them, inadequate incomes and low standards of living under frontier conditions, but their children grew up while those of the royal families were dying in spite of every attention that wealth could command and science could furnish.

If the infant mortality problem is to be solved on the basis of knowledge and reason, it must be recognized that sanitation and hygiene can not take the place of eugenics any more than eugenics can dispense with sanitation and hygiene. It must be recognized that the death-rate in childhood is largely selective, and that the most effective way to cut it down is to endow the children with better constitutions. This can not be done solely by any euthenic campaign; it can not be done by swatting the fly, abolishing the midwife, sterilizing the milk, nor by any of the other panaceas sometimes proposed.

But, it may be objected, this discussion ignores the actual facts. Statistics show that infant mortality campaigns have consistently produced reductions in the death-rate. The figures for New York, which could be matched in dozens of other cities, show that the number of deaths per 1,000 births, in the first year of life, has steadily declined since a determined campaign to "Save the Babies" was started:

To one who can not see beyond the immediate consequences of an action, such figures as the above indeed give quite a different idea of the effects of an infant mortality campaign, than that which we have just tried to create. And it is a great misfortune that euthenics so often fails to look beyond the immediate effect, fails to see what may happen next year, or 10 years from now, or in the next generation.

We admit that it is possible to keep a lot of children alive who would otherwise have died in the first few months of life. It is being done, as the New York figures, and pages of others that could be cited, prove. The ultimate result is twofold:

1. Some of those who are doomed by heredity to a selective death, but are kept alive through the first year, die in the second or third or fourth year. They must die sooner or later; they have not inherited sufficient resistance to survive more than a limited time. If they are by a great effort carried through the first year, it is only to die in the next. This is a statement which we have nowhere observed in the propaganda of the infant mortality movement; and it is perhaps a disconcerting one. It can only be proved by refined statistical methods, but several independent determinations by the English biometricians leave no doubt as to the fact. This work of Karl Pearson, E. C. Snow, and Ethel M. Elderton, was cited in our chapter on natural selection; the reader will recall how they showed that nature is weeding out the weaklings, and in proportion to the stringency with which she weeds them out at the start, there are fewer weaklings left to die in succeeding years.

To put the facts in the form of a truism, part of the children born in any district in a given year are doomed by heredity to an early death; and if they die in one year they will not be alive to die in the succeeding year, and vice versa. Of course there are in addition infant deaths which are not selective and which if prevented would leave the infant with as good a chance as any to live.

In the light of these researches, we are forced to conclude that baby-saving campaigns accomplish less than is thought; that the supposed gain is to some extent temporary and illusory.

2. There is still another consequence. If the gain is by great exertions made more than temporary; if the baby who would otherwise have died in the first months is brought to adult life and reproduction, it means in many cases the dissemination of another strain of weak heredity, which natural selection would have cut off ruthlessly in the interests of race betterment. In so far, then, as the infant mortality movement is not futile it is, from a strict biological viewpoint, often detrimental to the future of the race.

Do we then discourage all attempts to save the babies? Do we leave them all to natural selection? Do we adopt the "better dead" gospel?

Unqualifiedly, no! The sacrifice of the finer human feelings, which would accompany any such course, would be a greater loss to the race than is the eugenic loss from the perpetuation of weak strains of heredity. The abolition of altruistic and humanitarian sentiment for the purpose of race betterment would ultimately defeat its own end by making race betterment impossible.

But race betterment will also be impossible unless a clear distinction is made between measures that really mean race betterment of a fundamental and permanent nature, and measures which do not.

We have chosen the Infant Mortality Movement for analysis in this chapter because it is an excellent example of the kind of social betterment which is taken for granted, by most of its proponents, to be a fundamental piece of race betterment; but which, as a fact, often means race impairment. No matter how abundant and urgent are the reasons for continuing to reduce infant mortality wherever possible, it is dangerous to close the eyes to the fact that the gain from it is of a kind that must be paid for in other ways; that to carry on the movement without adding eugenics to it will be a short-sighted policy, which increases the present happiness of the world at the cost of diminishing the happiness of posterity through the perpetuation of inferior strains.

While some euthenic measures are eugenically evils, even if necessary ones, it must not be inferred that all euthenic measures are dysgenic. Many of them, such as the economic and social changes we have suggested in earlier chapters, are an important part of eugenics. Every euthenic measure should be scrutinized from the evolutionary standpoint; if it is eugenic as well as euthenic, it should be whole-heartedly favored; if it is dysgenic but euthenic it should be condemned or adopted, according to whether or not the gain in all ways from its operation will exceed the damage.

In general, euthenics, when not accompanied by some form of selection (i. e., eugenics) ultimately defeats its own end. If it is accompanied by rational selection, it can usually be indorsed. Eugenics, on the other hand, is likewise inadequate unless accompanied by constant improvement in the surroundings; and its advocates must demand euthenics as an accompaniment of selection, in order that the opportunity for getting a fair selection may be as free as possible. If the euthenist likewise takes pains not to ignore the existence of the racial factor, then the two schools are standing on the same ground, and it is merely a matter of taste or opportunity, whether one emphasizes one side or the other. Each of the two factions, sometimes thought to be opposing, will be seen to be getting the same end result, namely, human progress.

Not only are the two schools working for the same end, but each must depend in still another way upon the other, in order to make headway. The eugenist can not see his measures put into effect except through changes in law and custom--i. e., euthenic changes. He must and does appeal to euthenics to secure action. The social reformer, on the other hand, can not see any improvements made in civilization except through the discoveries and inventions of some citizens who are inherently superior in ability. He in turn must depend on eugenics for every advance that is made.

It may make the situation clearer to state it in the customary terms of biological philosophy. Selection does not necessarily result in progressive evolution. It merely brings about the adaptation of a species or a group to a given environment. The tapeworm is the stock example. In human evolution, the nature of this environment will determine whether adaptation to it means progress or retrogression, whether it leaves a race happier and more productive, or the reverse. All racial progress, or eugenics, therefore, depends on the creation of a good environment, and the fitting of the race to that environment. Every improvement in the environment should bring about a corresponding biological adaptation. The two factors in evolution must go side by side, if the race is to progress in what the human mind considers the direction of advancement. In this sense, euthenics and eugenics bear the same relation to human progress as a man's two legs do to his locomotion.

Social workers in purely euthenic fields have frequently failed to remember this process of adaptation, in their efforts to change the environment. Eugenists, in centering their attention on adaptation, have sometimes paid too little attention to the kind of environment to which the race was being adapted. The present book holds that the second factor is just as important as the first, for racial progress; that one leg is just as important as the other, to a pedestrian. Its only conflict with euthenics appertains to such euthenic measures as impair the adaptability of the race to the better environment they are trying to make.

Some supposedly euthenic measures opposed by eugenics are not truly euthenic, as for instance the limitation of a superior family in order that all may get a college education. For these spurious euthenic measures, something truly euthenic should be substituted.

Measures which show a real conflict may be typified by the infant mortality movement. There can be no doubt but that sanitation and hygiene, prenatal care and intelligent treatment of mothers and babies, are truly euthenic and desirable. At the same time, as has been shown, these euthenic measures result in the survival of inferior children, who directly or through their posterity will be a drag on the race. Euthenic measures of this type should be accompanied by counterbalancing measures of a more eugenic character.

Barring these two types, euthenics forms a necessary concomitant of the eugenic program; and, as we have tried to emphasize, eugenics is likewise necessary to the complete success of every euthenic program. How foolish, then, is antagonism between the two forces! Both are working toward the same end of human betterment, and neither can succeed without the other. When either attempts to eliminate the other from its work, it ceases to advance toward its goal. In which camp one works is largely a matter of taste. If on a road there is a gradient to be leveled, it will be brought down most quickly by two parties of workmen, one cutting away at the top, the other filling in the bottom. For the two parties to indulge in mutual scorn and recrimination would be no more absurd than for eugenics and euthenics to be put in opposition to each other. The only reason they have been in opposition is because some of the workers did not clearly understand the nature of their work. With the dissemination of a knowledge of biology, this ground of antagonism will disappear.

APPENDIX A

OVARIAN TRANSPLANTATION

In 1890, W. Heape published an account of some experiments with rabbits. Taking the fertilized egg of an angora rabbit (i. e., a long-haired, white one) from the oviduct of its mother previous to its attachment to the wall of the uterus, he transferred it to the uterus of a Belgian hare, a rabbit which is short-haired and gray. The egg developed normally in the new body and produced an animal with all the characteristics, as far as could be seen, of the real mother, rather than the foster-mother. Its coat was long and white, and there was not the slightest trace of influence of the short, gray-haired doe in whose body it had grown.

Here was a case in which environment certainly failed to show any modifying influence. But it was objected that the transplanted egg was already full-grown and fertilized when the transfer was made, and that therefore no modification need be expected. If the egg were transferred at an earlier stage, it was thought, the result might be different.

W. E. Castle and J. C. Phillips therefore undertook an experiment to which this objection should not be possible.

"A female albino guinea-pig just attaining sexual maturity was by an operation deprived of its ovaries, and instead of the removed ovaries there were introduced into her body the ovaries of a young black female guinea-pig, not yet sexually mature, aged about three weeks. The grafted animal was now mated with a male albino guinea-pig. From numerous experiments with albino guinea-pigs it may be stated emphatically that normal albinos mated together, without exception, produce only albino young, and the presumption is strong, therefore, that had this female not been operated on she would have done the same. She produced, however, by the albino male three litters of young, which together consisted of six individuals, all black. The first litter of young was produced about six months after the operation, the last about one year. The transplanted ovarian tissue must have remained in its new environment therefore from four to ten months before the eggs attained full growth and were discharged; ample time, it would seem, for the influence of a foreign body upon the inheritance to show itself were such influence possible."

While such experiments must not be stretched too far, in application to the human species, they certainly offer striking evidence of the fact that the characters of any individual are mainly due to something in the germ-plasm, and that this germ-plasm is to a surprising degree independent of any outside influence, even such an intimate influence as that of the body of the mother in which it reaches maturity.

APPENDIX B

"DYNAMIC EVOLUTION"

As C. L. Redfield has secured considerable publicity for his attempt to bolster up the Lamarckian theory, it deserves a few words of comment. His contention is that "the energy in animals, known as intelligence and physical strength, is identical with the energy known in mechanics, and is governed by the same laws." He therefore concludes that (1) an animal stores up energy in its body, in some undescribed and mystical way, and (2) that in some equally undescribed and mystical way it transmits this stored-up energy to its offspring. It follows that he thinks superior offspring are produced by parents of advanced age, because the latter have had more time to do work and store up energy for transmission. In his own words:

"Educating the grandfather helps to make the grandson a superior person.... We are, in our inheritance, exactly what our ancestors made us by the work they performed before reproducing. Whether our descendants are to be better or worse than we are will depend upon the amount and kind of work we do before we produce them."

The question of the influence of parental age on the characters of the offspring is one of great importance, for the solution of which the necessary facts have not yet been gathered together. The data compiled by Mr. Redfield are of value, but his interpretation of them can not be accepted for the following reasons.

1. In the light of modern psychology, it is absurd to lump all sorts of mental ability under one head, and to suppose that the father's exercise of reasoning power, for example, will store up "energy" to be manifested in the offspring in the shape of executive or artistic ability. Mental abilities are much subdivided and are inherited separately. Mr. Redfield's idea of the process is much too crude.

Moreover, Mr. Redfield's whole conception of the increase of intelligence with increase of age in a parent shows a disregard of the facts of psychology. As E. A. Doll has pointed out, in criticising Mr. Redfield's recent and extreme claim that feeble-mindedness is the product of early marriage, it is incorrect to speak of 20-, 30-, or 40-year standards of intelligence; for recent researches in measurement of mental development indicate that the heritable standard of intelligence of adults increases very little beyond the age of approximately 16 years. A person 40 years old has an additional experience of a quarter of a century, and so has a larger mental content, but his intelligence is still nearly at the 16-year level. Mental activity is the effect, not the cause, of mental growth or development. Education merely turns inherent mental powers to good account; it makes very little change in those powers themselves. To suppose that a father can, by study, raise his innate level of intelligence and transmit it at the new level to his son, is a naive idea which finds no warrant in the known facts of mental development.

2. In his entire conception of the storing-up and transmission of energy, Mr. Redfield has fallen victim to a confusion of ideas due to the use of the same word to mean two different things. He thinks of energy as an engineer; he declares the body-cell is a storage battery; he believes that the athlete by performing work stores up energy in his body (in some mysterious and unascertainable way) just as the clock stores up energy when it is wound. The incorrectness of supposing that the so-called energy of a man is of that nature, is remarkable. If, hearing Bismarck called a man of iron, one should analyze his remains to find out how much more iron he contained than ordinary men, it would be a performance exactly comparable to Mr. Redfield's, when he thinks of a man's "energy" as something stored up by work.

As a fact, a man contains less energy, after the performance of work, than he did at the start. All of his "energy" comes from the metabolism of food that he has previously eaten. His potential energy is the food stored up in his body, particularly the glycogen in the liver and muscles.

Why, then, can one man run faster than another? Mr. Redfield thinks it is because the sprinter has, by previous work, stored up energy in his body, which carries him over the course more rapidly than the sluggard who has not been subjected to systematic training. But the differences in men's ability are not due to the amount of energy they have stored up. It is due rather to differences in their structure (using this word in a very broad sense), which produce differences in the efficiency with which they can use the stored-up energy (i.e., food) in their bodies. A fat Shorthorn bull contains much more stored-up energy than does a race horse, but the latter has the better structure--cooerdination of muscles with nervous system, in particular--and there is never any doubt about how a race between the two will end. The difference between the results achieved by a highly educated thinker and a low-grade moron are similarly differences in structural efficiency: the moron may eat much more, and thereby have more potential energy, than the scholar; but the machine, the brain, can not utilize it.

The effects of training are not to store up energy in the body, for it has been proved that work decreases rather than increases the amount of energy in the body. How is it, then, that training increases a man's efficiency? It is obviously by improving his "structure," and probably the most important part of this improvement is in bringing about better relations between the muscles and the nerves. To pursue the analogy which Mr. Redfield so often misuses, the effect of training on the human machine is merely to oil the bearings and straighten out bent parts, to make it a more efficient transformer of the energy that is supplied to it.

The foundation stone of Mr. Redfield's hypothesis is his idea that the animal by working stores up energy. This idea is the exact reverse of the truth. While the facts which Mr. Redfield has gathered deserve much study, his idea of "Dynamic Evolution" need not be taken seriously.

APPENDIX C

THE "MELTING POT"

America as the "Melting Pot" of peoples is a picture often drawn by writers who do not trouble themselves as to the precision of their figures of speech. It has been supposed by many that all the racial stocks in the United States were tending toward a uniform type. There has never been any real evidence on which to base such a view, and the study completed in 1917 by Dr. Ales Hrdlicka, curator of the division of physical anthropology of the U. S. National Museum, furnishes evidence against it. He examined 400 individuals of the Old White American stock, that is, persons all of whose ancestors had been in the United States as far as the fourth ascending generation. He found little or no evidence that hereditary traits had been altered. Even the descendants of the Pilgrim Fathers, the Virginia cavaliers, the Pennsylvania Dutch and the Huguenots, while possibly not as much unlike as their ancestors were, are in no sense a blend.

The "Melting Pot," it must be concluded, is a figure of speech; and as far as physical anthropology is concerned, it will not be anything more in this country, at least for many centuries.

Announcing the results of study of the first 100 males and 100 females of his series, Dr. Hrdlicka said, "The most striking result of the examinations is the great range of variation among Old Americans in nearly all the important measurements. The range of variation is such that in some of the most significant determinations it equals not only the variation of any one group, but the combined variations of all the groups that enter into the composition of the Americans." This fact would be interpreted by the geneticist as an evidence of hybridity. It is clear that, at the very beginning, a number of diverse, although not widely differing, stocks must have made up the colonial population; and intermarriage and the influence of the environment have not welded these stocks into one blend, but have merely produced a mosaic-like mixture. This is good evidence of the permanence of inherited traits, although it must be qualified by the statement that it does not apply equally to all features of the body, the face, hands and feet having been found less variable, for instance, than stature and form of head.

ka's measurements represents the mean man of Colonial ancestry. The outline of the face is almost oblong; the head is high and well-developed, particularly in the regions which are popularly supposed to denote superior intelligence. In general, it is a highly specialized type, denoting an advanced evolution.]

The stature of both American men and women is high, higher than the average of any European nation except the Scotch. The individual variation is, however, enormous, amounting to 16.4% of the average in males and nearly 16% in females. For males, 174 cm. is the average height, for females 162. The arm spread in males is greater than their stature, in females it is less.

The average weight of the males is 154 lbs.[typo: missing comma?] of the females 130. Taking into consideration the tall stature, these weights are about equal to those among Europeans.

The general proportions of the body must be classed as medium, but great fluctuations are shown.

The face is, in general, high and oval; in females it occasionally gives the impression of narrowness. The forehead is well developed in both sexes. The nose is prevalently long and of medium breadth, its proportions being practically identical with those of the modern English. The ears are longer than those of any modern immigrants except the English. The mouth shows medium breadth in both sexes, and its averages exactly equal those obtained for modern French.

One of the most interesting results is that there were obtained among these first 200 individuals studied no pronounced blonds, although the ancestry is North European, where blondness is more or less prevalent. The exact distribution is:

Male Female

Light-brown 12% 16% Medium-brown to dark 77 68 Very dark 11 6 Golden-red and red 0 10

Dr. Hrdlicka's classification of the eye is as follows:

The head among Old Americans is in many cases notable for its good development, particularly in males. Among 12 groups of male immigrants measured at Ellis Island under Dr. Hrdlicka's direction in recent years, not one group quite equals in this respect the Americans, the nearest approach being noted in the Irish, Bohemians, English, Poles, and North Italians. The type of head, however, differs among the Americans very widely, as is the case with most civilized races at the present day.

Head form is most conveniently expressed by means of the cephalic index, that is, the ratio of breadth to length. Anthropologists generally speak of any one with an index of 75 (or where the breadth is 75% of the length) and below this as dolichocephalic, or long-headed; from 75 to 80 is the class of the mesocephalic, intermediates; while above 80 is that of the subbrachycephalic and brachycephalic, or round-headed. For the most part, the Old Americans fall into the intermediate class, the average index of males being 78.3 and that of females 79.5.

Barring a few French Huguenots, the Old Americans considered here are mostly of British ancestry, and their head form corresponds rather closely to that of the English of the present day. In England, as is well known, the round-headed type of Central and Eastern Europe, the Alpine or Celto-Slav type, has few representatives. The population is composed principally of long-headed peoples, deriving from the two great European stocks, the Nordic and the Mediterranean. To the latter the frequency of dark hair and brown eyes is probably due, both in England and America.

While the average of the Old Americans corresponds closely to the average of the English, there is a great deal of variation in both countries. Unfortunately, it is impossible to compare the present Americans with their ancestors, because measurements of the latter are lacking. But to assume that the early colonists did not differ greatly from the modern English is probably justifiable. A comparison of modern Americans (of the old white stock) with modern English should give basis for an opinion as to whether the English stock underwent any marked modifications, on coming to a new environment.

It has already been noted that the average cephalic index is practically the same; the only possibility of a change then lies in the amount of variability. Is the American stock more or less variable? Can a "melting pot" influence be seen, tending to produce homogeneity, or has change of environment rather produced greater variability, as is sometimes said to be the case?

The amount of variability is most conveniently measured by a coefficient known as the standard deviation ([Greek: s]), which is small when the range of variation is small, but large when diversity of material is great. The following comparisons of the point at issue may be made.

Avg. [Greek: s]

For the men, little difference is discernible. The Old Americans are slightly more long-headed than the English, but the amount of variation in this trait is nearly the same on the two sides of the ocean.

The average of the American women is 79.5 with [Greek: s] = 2.6. No suitable series of English women has been found for comparison.(203) It will be noted that the American women are slightly more round-headed than the men; this is found regularly to be the case, when comparisons of the head form of the two sexes are made in any race.

In addition to establishing norms or standards for anthropological comparison, the main object of Dr. Hrdlicka's study was to determine whether the descendants of the early American settlers, living in a new environment and more or less constantly intermarrying, were being amalgamated into a distinct sub-type of the white race. It has been found that such amalgamation has not taken place to any important degree. The persistence in heredity of certain features, which run down even through six or eight generations, is one of the remarkable results brought out by the study.

If the process could continue for a few hundred years more, Dr. Hrdlicka thinks, it might reach a point where one could speak of the members of old American families as of a distinct stock. But so far this point has not been reached; the Americans are almost as diverse and variable, it appears, as were their first ancestors in this country.

APPENDIX D

THE ESSENCE OF MENDELISM

It is half a century since the Austrian monk, Gregor Mendel, published in a provincial journal the results of his now famous breeding experiments with garden peas. They lay unnoticed until 1900, when three other breeders whose work had led them to similar conclusions, almost simultaneously discovered the work of Mendel and gave it to the world.

Breeding along the lines marked out by Mendel at once became the most popular method of attack, among those who were studying heredity. It became an extremely complicated subject, which can not be grasped without extended study, but its fundamentals can be briefly summarized.

Inherited differences in individuals, it will be admitted, are due to differences in their germ-plasms. It is convenient to think of these differences in germ-plasms (that is, differences in heredity) as being due to the presence in the germ-plasm of certain hypothetical units, which are usually referred to as factors. The factor, nowadays, is the ultimate unit of Mendelian research. Each of these factors is considered to be nearly or quite constant,--that is, it undergoes little, or no change from generation to generation. It is ordinarily resistant to "contamination" by other factors with which it may come in contact in the cell. The first fundamental principle of Mendelism, then, is the existence of relatively constant units, the Mendelian factors, as the basis for transmission of all the traits that go to make up an animal or plant.

Experimental breeding gives reason to believe that each factor has one or more alternatives, which may take its place in the mechanism of heredity, thereby changing the visible character of the individual plant or animal in which it occurs. To put the matter a little differently, one germ-cell differs from another in having alternatives present in place of some of the factors of the latter. A given germ-cell can never have more than one of the possible alternatives of each factor. These alternatives of a factor are called its allelomorphs.

Now a mature germ-cell has a single system of these factors: but when two germ-cells unite, there result from that union two kinds of cells--namely, immature germ-cells and body-cells; and both these kinds of cells contain a double system of factors, because of course they have received a single entire system from each parent. This is the second of the fundamental principles of Mendelism: that the factors are single in the mature germ-cell, but in duplicate in the body-cell (and also in the immature germ-cell).

In every cell with a double system of factors, there are necessarily present two representatives from each set of allelomorphs, but these may or may not be alike--or in technical language the individual may be homozygous, or heterozygous, as regards the given set of alternative factors. Looking at it from another angle, there is a single visible character in the plant or animal, but it is produced by a double factor, in the germ-plasm.

When the immature germ-cell, with its double system of factors, matures, it throws out half the factors, retaining only a single system: and the allelomorphic factors which then segregate into different cells are, as has been said above, ordinarily uninfluenced by their stay together.

But the allelomorphic factors are not the only ones which are segregated into different germ-cells, at the maturation of the cell; for the factors which are not alternative are likewise distributed, more or less independently of each other, so that it is largely a matter of chance whether factors which enter a cross in the same germ-cell, segregate into the same germ-cell or different ones, in the next generation. This is the next fundamental principle of Mendelism, usually comprehended under the term "segregation," although, as has been pointed out, it is really a double process, the segregation of alternative factors being a different thing from the segregation of non-alternative factors.

From this fact of segregation, it follows that as many kinds of germ-cells can be formed by an individual, as there are possible combinations of factors, on taking one alternative from each pair of allelomorphs present. In practice, this means that the possible number of different germ-cells is almost infinitely great, as would perhaps be suspected by anyone who has tried to find two living things that are just alike.

Such is the essence of Mendelism; and the reader is probably ready to admit that it is not a simple matter, even when reduced to the simplest terms. To sum up, the principal features at the base of the hypothetical structure are these:

1. There exist relatively constant units in the germ-plasm.

2. There are two very distinct relationships which these units may show to each other. Two (or more) unit factors may be alternatives in the mechanism of inheritance, indicating that one is a variation (or loss) of the other; or they may be independent of each other in the mechanism of inheritance.

3. The mature germ-cell contains a single system of independent factors (one representative from each set of alternates).

The immature germ-cells, and body-cells, have double systems of independent factors (two from each set of alternatives).

4. The double system arises simply from the union of two single systems (i. e., two germ-cells), without union or even contamination of the factors involved.

In the formation of a single system (mature germ-cells) from a double (immature germ-cells), pairs of alternates separate, passing into different germ-cells. Factors not alternates may or may not separate--the distribution is largely a matter of chance.

Such are the fundamental principles of Mendelism; but on them was early grafted a theoretical structure due mainly to the German zooelogist, August Weismann. To understand his part in the story, we must advert to that much mooted and too often misunderstood problem furnished by the chromosomes. (See Fig. 46.) These little rods of easily stained material, which are found in every cell of the body, were picked out by Professor Weismann as the probable carriers of heredity. With remarkable acuteness, he predicted their behavior at cell-division, the intricate nature of which is usually the despair of every beginner in biology. When Mendelian breeding, in the early years of this century, showed temporary pairing and subsequent separation of units in the germ-cell, it was soon realized that the observed facts of breeding fitted to a nicety the observed facts (predicted by Weismann) of chromosome-behavior; for at each cell-division the chromosomes, too, pair and separate again. The observed behavior of transmitted characters in animals and plants followed, in so many cases, the observed behavior of the chromosomes, that many students found it almost impossible to believe that there was no connection between the two, and Dr. Weismann's prediction, that the chromosomes are the carriers of heredity, came to be looked on as a fact, by many biologists.

But when so much of Professor Weismann's system was accepted, other parts of it went along, including a hypothetical system of "determiners" in the chromosome, which were believed to determine the development of characters in the organism. Every trait of an animal or plant, it was supposed, must be represented in the germ-plasm by its own determiner; one trait, one determiner. Did a notch in the ear run through a pedigree? Then it must be due to a determiner for a notch in the ear in the germ-plasm. Was mathematical ability hereditary? Then there must be a determiner, the expression of which was mathematical ability.

For a while, this hypothesis was of service in the development of genetics; some students even began to forget that it was a hypothesis, and to talk as if it were a fact. But the exhaustive tests of experimental breeding of plants and animals have long caused most of the advanced students of genetics to drop this simple hypothesis.

In its place stands the factorial hypothesis, evolved by workers in America, England, and France at about the same time. As explained in Chapter V, this hypothesis carries the assumption that every visible character is due to the effects of not one but many factors in the germ-cell.

In addition to these fundamentals, there are numerous extensions and corollaries, some of them of a highly speculative nature. The reader who is interested in pursuing the subject farther must turn to one of the text-books on Mendelism.

In plant-breeding a good deal of progress has been made in the exact study of Mendelian heredity; in animal breeding, somewhat less; in human heredity, very little. The reason is obvious: that experiments can not be made in man, and students must depend on the results of such matings as they can find; that only a very few offspring result from each mating; and that generations are so long that no one observer can have more than a few under his eyes. These difficulties make Mendelian research in man a very slow and uncertain matter.

Altogether, it is probable that something like a hundred characters in man have been pointed out as inherited in Mendelian fashion. A large part of these are pathological conditions or rare abnormalities.

But the present writers can not accept most of these cases. It has been pointed out in Chapter V that there are good reasons for doubting that feeble-mindedness is inherited in a simple Mendelian fashion, although it is widely accepted as such. We can not help feeling that in most cases heredity in man is being made to appear much simpler than it really is; and that particularly in mental characters, analysis of traits has by no means reached the bottom.

If we were asked to make out a list of characters, as to the Mendelian inheritance of which there could be little doubt, we would hardly be able to go farther than the following:

The sex-linked characters (one kind of color-blindness, hemophilia, one kind of night-blindness, atrophy of the optic nerve, and a few other rare abnormalities).

Albinism. This appears to be a recessive, but probably involves multiple allelomorphs in man, as in other animals.

Brachydactyly, apparently a dominant. This is so much cited in text-books on Mendelism that the student might think it is a common character. As a fact, it is extremely rare, being found in only a few families. The similar trait of orthodactyly or symphalangism, which likewise appears to be a good Mendelian dominant, seems to exist in only one family. Traits like these, which are easily defined and occur very rarely, make up a large part of the cases of probably Mendelian heredity. They are little more than curiosities, their rarity and abnormal nature depriving them of evolutionary significance other than to demonstrate that Mendelian heredity does operate in man.

White blaze in the hair or, as it might better be called to show its resemblance to the trait found in other mammals, piebaldism. A rather rare dominant.

Huntington's Chorea, which usually appears to be a good dominant, although the last investigators (Muncey and Davenport) found some unconformable cases.

A few abnormalities, such as a premature graying of the hair (one family cited by K. Pearson) are well enough attested to be admitted. Many others, such as baldness, are probably Mendelian but not yet sufficiently supported by evidence.

None of these characters, it will be observed, is of much significance eugenically. If the exact manner of inheritance of some of the more important mental and physical traits were known, it would be of value. But it is not a prerequisite for eugenic action. Enough is known for a working program.

To sum up: the features in the modern view of heredity, which the reader must keep in mind, are the following:

1. That the various characters which make up the physical constitution of any individual plant or animal are due to the action (concurrently with the environment, of course) of what are called, for convenience, factors, separable hypothetical units in the germ-plasm, capable of independent transmission.

2. That each visible character is due to the cooeperative action of an indefinitely large number of factors; conversely, that each of these factors affects an indefinitely large number of characters.

APPENDIX E

USEFUL WORKS OF REFERENCE

The most complete bibliography is that published by the State Board of Charities of the State of New York (Eugenics and Social Welfare Bulletin No. III, pp. 130, Albany, 1913).

An interesting historical review of eugenics, with critical comments on the literature and a bibliography of 100 titles, was published by A. E. Hamilton in the Pedagogical Seminary, Vol. XXI, pp. 28-61, March, 1914.

Much of the important literature of eugenics has been mentioned in footnotes. For convenience, a few of the books which are likely to be most useful to the student are here listed:

GENETICS AND EUGENICS, by W. E. Castle. Harvard University Press, Cambridge, 1916.

HEREDITY AND ENVIRONMENT IN THE DEVELOPMENT OF MEN, by Edwin G. Conklin. Princeton University Press, 1915.

HEREDITY IN RELATION TO EUGENICS, by C. B. Davenport, Henry Holt and Co., New York, 1911.

ESSAYS IN EUGENICS, by Francis Galton. Eugenics Education Society, London, 1909.

BEING WELL-BORN, by Michael F. Guyer. Indianapolis, Bobbs-Merrill Co., 1916.

THE SOCIAL DIRECTION OF HUMAN EVOLUTION, by W. E. Kellicott. New York, 1911.

THE PHYSICAL BASIS OF SOCIETY, by Carl Kelsey. New York, D. Appleton & Co., 1916.

EUGENICS, by Edward Schuster. Collins' Clear Type Press, London and Glasgow, 1913.

HEREDITY, by J. Arthur Thompson. Edinburgh, 1908.

GENETICS, by Herbert E. Walter. The Macmillan Co., New York, 1913.

AN INTRODUCTION TO EUGENICS, by W. C. D. Whetham and C. D. Whetham. Macmillan and Co., London, 1912.

HEREDITY AND SOCIETY, by W. C. D. Whetham and C. D. Whetham. Longmans, Green & Co., London, 1912.

THE FAMILY AND THE NATION, by W. C. D. Whetham and C. D. Whetham. Longmans, Green & Co., London, 1909.

The publications of the Galton Laboratory of National Eugenics, University of London, directed by Karl Pearson, and of the Eugenics Record Office, Cold Spring Harbor, Long Island, N. Y., directed by C. B. Davenport, furnish a constantly increasing amount of original material on heredity.

The principal periodicals are the Journal of Heredity (organ of the American Genetic Association), 511 Eleventh St., N. W., Washington, D. C. (monthly); and the Eugenics Review (organ of the Eugenics Education Society), Kingsway House, Kingsway, W. C., London (quarterly). These periodicals are sent free to members of the respective societies. Membership in the American organization is $2 a year, in the English 1 guinea a year, associate membership 5 shillings a year.

APPENDIX F

GLOSSARY

ACQUIRED CHARACTER, a modification of a germinal trait after cell fusion. It is difficult to draw a line between characters that are acquired and those that are inborn. The idea involved is as follows: in a standard environment, a given factor in the germ-plasm will develop into a trait which varies not very widely about a certain mean. The mean of this trait is taken as representing the germinal trait in its typical condition. But if the environment be not standard, if it be considerably changed, the trait will develop a variation far from the mean of that trait in the species. Thus an American, whose skin in the standard environment of the United States would be blonde, may under the environment of Cuba develop into a brunette. Such a wide variation from the mean thus caused is called an acquired character; it is usually impressed on the organism after the germinal trait has reached a full, typical development.

ALLELOMORPH (one another form), one of a pair of factors which are alternative to each other in Mendelian inheritance. Instead of a single pair, there may be a group of "multiple allelomorphs," each member being alternative to every other member of the group.

ALLELOMORPHISM, a relation between two or more factors, such that two which are present in one zygote do not both enter into the same gamete, but are separated into sister gametes.

BIOMETRY (life measure), the study of biology by statistical methods.

BRACHYDACTYLY (short-finger), a condition in which the bones, particularly of the fingers and toes, fail to grow to their normal length. In well-marked cases one of these is a reduction from three phalanges or joints to two.

CHARACTER (a contraction of "characteristic"), a term which is used, often rather vaguely, to designate any function, feature, or organ of the body or mind.

CHROMOSOME (color body, so called from its affinity for certain stains), a body of peculiar protoplasm, in the nucleus of the cell. Each species has its own characteristic number; the cells of the human body contain 24 chromosomes each.

CONGENITAL (with birth), present at birth. The term fails to distinguish between traits which are actually inherited, and modifications acquired during prenatal life. In the interest of clear thinking its use should be avoided so far as possible.

CORRELATION (together relation), a relation between two variables in a certain population, such that for every variation of one, there is a corresponding variation of the other. Mathematically, two correlated variables are thus mutually dependent. But a correlation is merely a statistical description of a particular case, and in some other population the same two variables might be correlated in a different way, other influences being at work on them.

CYTOLOGY (cell word), the study of the cell, the constituent unit of organisms.

DETERMINER (completely end), an element or condition in a germ-cell, supposed to be essential to the development of a particular quality, feature, or manner of reaction of the organism which arises from that germ-cell. The word is gradually falling into disuse, and "factor" taking its place.

DOMINANCE (mastery), in Mendelian hybrids the capacity of a character which is derived from only one of two generating gametes to develop to an extent nearly or quite equal to that exhibited by an individual which has derived the same character from both of the generating gametes. In the absence of dominance the given character of the hybrid usually presents a "blend" or intermediate condition between the two parents.

DYSGENIC (bad origin), tending to impair the racial qualities of future generations; the opposite of eugenic.

ENDOGAMY (within mating), a custom of some primitive peoples, in compliance with which a man must choose his wife from his own group (clan, gens, tribe, etc.).

EUGENIC (good origin), tending to improve the racial qualities of future generations, either physical or mental.

EUTHENIC (good thriving), tending to produce beneficial acquired characters or better conditions for people to live in, but not tending (except incidentally and indirectly) to produce people who can hand on the improvement by heredity.

EVOLUTION (unroll), ORGANIC, the progressive change of living forms, usually associated with the development of complex from simple forms.

EXOGAMY (out mating), a custom of primitive peoples which requires a man to choose a wife from some other group (clan, gens, tribe, etc.) than his own.

FACTOR (maker), a name given to the hypothetical something, the independently inheritable element in the germ-cell, whose presence is necessary to the development of a certain inherited character or characters or contributes with other factors to the development of a character. "Gene" and "determiner" are sometimes used as synonyms of factor.

FEEBLE-MINDEDNESS, a condition in which mental development is retarded or incomplete. It is a relative term, since an individual who would be feeble-minded in one society might be normal or even bright in another. The customary criterion is the inability of the individual, because of mental defect existing from an early age, to compete on equal terms with his normal fellows, or to manage himself or his affairs with ordinary prudence. American students usually distinguish three grades of mental defect: Idiots are those who are unable to take care of themselves, even to the extent of guarding against common physical dangers or satisfying physical needs. Their mentality does not progress beyond that of a normal two-year-old child. Imbeciles can care for themselves after a fashion, but are unable to earn their living. Their mental ages range from three to seven years, inclusive. Morons, who correspond to the common acceptation of the term feeble-minded, "can under proper direction become more or less self-supporting but they are as a rule incapable of undertaking affairs which demand judgment or involve unrestricted competition with normal individuals. Their intelligence ranges with that of normal children from seven to twelve years of age." There is necessarily a considerable borderline, but any adult whose intelligence is beyond that of the normal twelve-year-old child is usually considered to be not feeble-minded.

GAMETE (mate), a mature germ-cell; in animals an ovum or spermatozooen.

GENETICS (origins), for a long time meant the study of evolution by experimental breeding and was often synonomous with Mendelism. It is gradually returning to its broader, original meaning of the study of variation and heredity, that is, the origin of the individual's traits. This broader meaning is preferable.

GERMINAL (sprig), due to something present in the germ-cell. A trait is germinal when its basis is inherited,--as eye color,--and when it develops with nothing more than the standard environment; remaining relatively constant from one generation to another, except as influenced by reproduction.

GERM-PLASM (sprig form), mature germ-cells and the living material from which they are produced.

HAEMOPHILIA (blood love), an inability of the blood to clot. It thus becomes impossible to stop the flow of blood from a cut, and one who has inherited haemophilia usually dies sooner or later from haemorrhage.

HEREDITY (heirship), is usually considered from the outside, when it may properly be defined as organic resemblance based on descent, or the correlation between relatives. But a better definition, based on the results of genetics, looks at it as a mechanism, not as an external appearance. From this point of view, heredity may be said to be "the persistence of certain cell-constituents (in the germ-cells) through an unending number of cell-divisions."

HETEROZYGOTE (different yolk), a zygotic individual which contains both members of an allelomorphic pair.

HOMOZYGOTE (same yolk), an individual which contains only one member of an allelomorphic pair, but contains that in duplicate, having received it from both parents. A homozygous individual, having been formed by the union of like gametes, in turn regularly produces gametes of only one kind with respect to any given factor, thus giving rise to offspring which are, in this regard, like the parents; in other words, homozygotes regularly "breed true." An individual may be a homozygote with respect to one factor and a heterozygote with respect to another.

HORMONES (chain), the secretions of various internal glands, which are carried in the blood and have an important specific influence on the growth and functioning of various parts of the body. Their exact nature is not yet understood.

INBORN usually means germinal, as applied to a trait, and it is so used in this book. Strictly speaking, however, any trait which appears in a child at birth might be called inborn, and some writers, particularly medical men, thus refer to traits acquired in prenatal life. Because of this ambiguity the word should be carefully defined when used, or avoided.

INHERENT (in stick), as used in this book, is synonymous with germinal.

INDUCTION (in lead), a change brought about in the germ-plasm with the effect of temporarily modifying the characters of an individual produced from that germ-plasm; but not of changing in a definite and permanent way any such germ-plasm and therefore any individual inherited traits.

INNATE (inborn), synonymous with inborn.

LATENT (lie hidden), a term applied to traits or characters whose factors exist in the germ-plasm of an individual, but which are not visible in his body.

LAW, in natural science means a concise and comprehensive description of an observed uniform sequence of events. It is thus quite different from the law of jurists, who mean a rule laid down for the guidance of an intelligent being, by an intelligent being having power over him.

MENDELISM, a collection of laws of heredity (see Appendix D) so-called after the discoverer of the first of them to become known; also the analytical study of heredity with a view to learning the constitution of the germ-cells of animals and plants.

MENDELIZE, to follow Mendel's laws of inheritance.

MORES (customs), the approved customs or unwritten laws of a people; the conventions of society; popular usage or folk-ways which are reputable.

MUTATION (change), has now two accepted meanings: (1) a profound change in the germ-plasm of an organism such as will produce numerous changes in its progeny; and (2) a discontinuous heritable change in a Mendelian factor. It is used in the first sense by De Vries and other "mutationists" and in the second sense by Morgan and other Mendelists; confusion has arisen from failure to note the difference in usage.

NORMAL CURVE, the curve of distribution of variations of something whose variations are due to a multiplicity of causes acting nearly equally in both directions. It is characterized by having more individuals of a mediocre degree and progressively fewer above and below this mode.

NUCLEUS (little nut), a central, highly-organized part of every living cell, which seems to play a directive role in cell-development and contains, among other things, the chromosomes.

PATENT (lie open), a term applied to traits which are manifestly represented in the body as well as the germ-plasm of an individual. The converse of "latent."

PROBABILITY CURVE, the same as normal curve. Also called a Gaussian curve.

PROTOPLASM (first form), "the physical basis of life"; a chemical compound or probably an emulsion of numerous compounds. It contains proteins which differ slightly in many species of organism. It contains carbon, hydrogen, oxygen, nitrogen, sulphur, and various salts, but is so complex as to defy exhaustive analysis.

PSYCHIATRY (soul healing), the study of diseases of the mind.

RECESSIVE (draw back), the converse of dominant; applied to one of a pair of contrasted Mendelian characters which can not appear in the presence of the other.

REGRESSION (back go), the average variation of one variable for a unit variation of a correlated variable.

SEGREGATION (aside flock), (1) as used in eugenics means the policy of isolating feeble-minded and other anti-social individuals from the normal population into institutions, colonies, etc., where the two sexes are kept apart. (2) The term is also used technically in genetics, to refer to the discontinuity of the variation of characteristics resulting from the independent distribution of factors before or at the time of formation of the gametes.

SELECTION (apart pick), the choice (for perpetuation by reproduction) from a mixed population, of the individuals possessing in common a certain character or a certain degree of some character. Two kinds of selection may be distinguished: (1) natural selection, in which choice is made automatically by the failure to reproduce (through death or some other cause) of the individuals who are not "fit" to pass the tests of the environment (vitality, disease resistance, speed, success in mating, or what not); and (2) artificial selection, in which the choice is made consciously by man, as a livestock breeder.

SEX-LIMITED, a term applied to traits which differ in the two sexes, because influenced by the hormones of the reproductive glands. Example, the beard.

SEX-LINKED, a term applied to traits which are connected with sex accidentally and not physiologically in development. The current explanation is that such traits happen to be in the same chromosome as the determiner of maleness or femaleness, as the case may be. Color-blindness is the classical example in man.

SEXUAL SELECTION, the conscious or unconscious preference by individuals of one sex, or by that sex as a whole, for individuals of the other sex who possess some particular attribute or attributes in a degree above or below the average of their sex. If the deviation of the chosen character is in the same direction (plus or minus) as in the chooser, the mating is called assortative; if in one direction independent of the characteristic of the chooser, it is called preferential.

SOMA (body), the body as distinguished from the germ-plasm. From this point of view every individual consists of only two parts,--germ-plasm and soma or somatoplasm.

TRAIT, a term used by geneticists as a synonym of "character."

UNIT-CHARACTER, in Mendelian heredity a character or alternative difference of any kind, which is apparently not capable of subdivision in heredity, but is inherited as a whole, and which is capable of becoming associated in new combinations with other characters. The term is now going out of use, as it makes for clearer thinking about heredity to fix the attention on the factors of the germ-cells instead of on the characters of the adult.

VARIATION, a deviation in the size, shape, or other feature of a character or trait, from the mean or average of that character in the species.

VESTIGIAL (footstep), a term applied to a character which at some time in the evolutionary history of the species possessed importance, or functioned fully, but which has now lost its importance or its original use, so that it remains a mere souvenir of the past, in a degenerated condition. Example, the muscles which move a man's ears.

ZYGOTE (yolk), the fertilized egg-cell; the united cell formed by the union of the ovum and spermatozooen after fertilization.

ZYMOTIC, caused by a microoerganism,--a term applied to diseases. Example, tuberculosis.

INDEX

A

Abderholden, E., 422

Acquired character, 437

Administrative aspects, 194

Adult mortality, 345

Afghans, 321

Agriculture, 307

Aguinaldo, E., 314

Aims of eugenics, 152

Albinism, 433

Aleurone, 104

Allelomorphism, 437

Alpine Type, 427

America, 432

American Breeders Assn., 154, 194

American Breeders Magazine, 154

American Prison Assn., 182

American Genetic Assn., 154, 277

American-Chinese Marriages, 313

Amherst College, 255, 266

Ancestral Inheritance Law, 112

Anglian, 426

Anglo-Saxon, 426

Anthropological Soc. of Denmark, 155

Apartment houses, 377

Appropriate opportunity, 366

Argentina, 326

Aristocracy, 362

Aristodemocracy, 362

Aristotle, 32

Arizona, 187

Arkansas, 241

Army, American, 83

Arsenic, 63

Asiatic immigration, 311

Asiatic Turkey, 299

Assortative mating, 126, 211

Athenians, 133

Atrophy of optic nerve, 433

Australian, 129

Australian marriages, 222

Automobile, effect of 377

B

Baby saving campaign, 408

Bachelors, tax on, 353

Back to the farm movement, 355

Backward children, 188

Bahama Islands, 203

Barrington, A., 13

Bean and Mall, 285

Beggars, 302

Bermuda, 205

Bertholet, E., 57

Bertillon, J., 140

Better babies movement, 155

Binet tests, 287

Biometric method, 31

Biometry, 437

Birth control, 269

Bisexual societies, 234

Bleeders, 38

Blindness, 32

Boer-Hottentot mulattoes, 300

Body-plasm, 27

Brachybioty, 409

Brachycephalic heads, 427

Bradlaugh, C., 269

Breton race, 273

Brigham Young College, 219

British, 427

British Columbia, 305

British Indian immigration, 312

Bryn Mawr College, 240, 263

C

Caffeine, 45

California University, 100

Cambridge graduates, 428

Cambridge, Mass., 261

Carnegie Institution of Washington, 154

Carnegie, Margaret Morrison, School, 278

Carpenter, E., 379

Celibacy, 173

Celtic, 41

Celto-Slav Type, 427

Central Europe, 427

Charm and taboo, 395

Chicks, 47

Child bearing, Effect of, 346

Child Labor, 368

Childless wives, 268

Child mortality, 403, 407

Children surviving per capita, 267

Chinese immigration, 321

Chorea, Huntingdon's, 109, 433

Church acquaintances, 234

Civic Club (Pittsburgh, Penn.), 371

Cleopatra, 207

Climate, 42

Coefficient of correlation, 212

Coercive means, 184

Cold Spring Harbor, 100

Coldness, 251

Collateral inheritance, 404

College women, 241

Colonial ancestry, 426

Colony plan, 188

Color line, 280

Color-blindness, 109, 433

Columbia, District of, 187

Columbus, Ohio, 261

Combemale, 44

Compulsory education, 369

Confederate Army, 323

Congenital, 438

Connecticut Agricultural College, 82, Fig. 14

Consanguinity, 207

Conscription, 319

Continuity of germ-plasm, 29

Controlled association tests, 288

Corn, Fig. 2

Cornell Medical College, 45

Cost of clothing, 274

Cost of domestic labor, 275

Cost of food, 274

Cost of medical attention, 275

Cousins, 202

Croatians, 427

Crum, Frederick S., 259

Cynical attitude, 249

Cytology, 438

D

Dalmatians, 311

Dance acquaintances, 234

Dark family, 168

Darwinism, 214

Davies, Maria Thompson, 235

Declaration of Independence, 75

Defective germ-plasm, 194

Defectives, 302

Definition of eugenics, 147, 152

Degenerate persons, 193

Delaware, 187

Delayed marriage, 217

Delinquents, 302

Democracy, 360

Denmark, 137

Dependents, 302

Desirability of Restrictive Eugenics, 167

Destitute classes, 214

Differences among men, 75

Diseases, 38

Disease resistance, 402

Distribution, 307

District of Columbia, 187

Divorce, 201

Dolichocephalic heads, 427

Dominance, 438

Dominant, 433

Drinkwater, 342

Drosophila, 101

Drug fiends, 193

Drunkenness, 389

Durant scholarship, 262

Dyer family, 206

Dynamic evolution, 421

Dynamic of manhood, 223

Dysgenic, definition of, 438

Dysgenic types, 176

E

Early marriages, 247

Eastern Europe, 427

East north central states, 358

East south central states, 358

Ebbinghaus tests, 288

Economic determinism, 365

Economic equality of sexes, 380

Economic status, 250

Economic standing of parents, 370

Edinburgh, 57

Education, compulsory, 368

Education and race suicide, 253

Elevation of standards, 277

Emancipation of women, 364

Equalitarianism, 362

Equality, 229

Equality of opportunity, 366

Equal pay for equal work, 380

Essence of Mendelism, 429

Eugenic aspect of specific reforms, 352

Eugenic laws, 191

Eugenic marriages, 352

Eugenics and euthenics, 438

Eugenics Education Society, 153

Eugenics movement, 147

Eugenics registry, 350

Eugenics Review, 436

Eugenics and social welfare, Bulletin, 435

Euthenics, eugenics and, 402

Evolution, 438

F

Facial attractiveness, 215

Family alignment, 229

Fecundal selection, 137

Feebly inhibited, 182

Feeble-mindedness, 71, 176

Fernandez brothers, 314

Fertility, relative, 247

Filipinos, 315

Financial aspect, 173

Financial success, 219

Finger prints, Fig. 25

Florida, 187

Foot, Egyptian, Fig. 6

Foreign-born, 238

Formal social functions, 236

Franco-Prussian war, 321

Frederick the Great, 19

Fredericksburg, Va., 288

Freiburg, University, of, 125

French-Canadians, 259

French revolution, 18

G

Gallichan, W., 252

Galton, Eugenics Laboratory, 153, 349

Galton Laboratory of National Eugenics, 269, 436

Galton-Pearson law, 113, 114

Garibaldi, G., 19

Genealogy and eugenics, 329, 439

Genesis, 64

Genius, hereditary, 151

Georgia, 187

Geographical distribution, 261

German society for race hygiene, 163

Germinal, 439

Gifted families, 213

Gochuico, Ricardo, 315

Gonorrhea, 63

Great race, 426

Greek idea of eugenics, 150

Greek slaves, 284

Greenwood lake, 233

Growth of eugenics, 147

Gruber von, and Rubin, 204

Guatemala Indians, 356

Gustavus Adolphus, 19

H

Habitual criminal, 194

Hair, white blaze in, 433

Hanks Family, 333

Hartford, Conn., 261

Hebrews, East European, 299

Hebrews, Russian, 302

Helsingfors, 54

Hereditary genius, 16, 151

Hereditary, 440

Heredity, laws of, 99

Heredity, talent and genius, 151

Herzegovinians, 311

Heterozygote, 440

Hickory Family, 168

Higher education, 276

Hill folk, 168

Hodge, 44

Hollingworth, H. L., 342

Home acquaintances, 234

Homo sapiens, 300

Homozygote, 440

Homozygous, 427

Hopetown, 203

Hormones, 440

Housing, 376

Howard University, 388

Humanistic religion, 396

Humanitarian aspect, 171

Huntington, E., 42

Huntington's Chorea, 180

I

Illegitimacy, 325

Illegitimate children, 208, 386

Illinois, University of, 244

Ilocano, 315

Imbeciles, 188

Immigration, 298

Immigration Commission, 304, 310

Immortality, 29

Improvement of sexual selection, 211

Inborn, definition of, 440

Inborn characters, 32

Income Tax, 353

Increasing the marriage rate of the superior, 237

Indian, American, 49, 130

Individualism, 253

Induction, 440

Infant mortality, 121, 413

Infant mortality movement, 414

Infusorian, 26

Inherent, 440

Inheritance of mental capacities, 84

Inheritance Tax, 353

Inkowa Camp, 233

Inquiries into human faculty, 5, 152

Insanity, 178

Institut Solvay, 155

Intelligence, 106

Intermarriage, 206

International Eugenics Congress, 155

International Eugenics Society, 155

Isabella, Queen of Spain, 19

Ishmael Family, 168

Italians, Southern, 304

Ireland, 299

J

Jacob, 64

Jamaica, 289

Japanese, 127

Japanese immigration, 312

Jefferson, T., 75

Jefferson Reformatory, 191

Jena, Battle of, 321

Jewish eugenics, 394

Jewish race, 358

Journal of Heredity, 154, 436

Judaism, 394

K

Kaiser of Germany, 204

Kallikak Family, 160

Kansas City, Mo., 261

Kansas State Agrigultural College, 244

Kechuka Camp, 435

Kentucky, 172

L

Laban, 64

Lamarckian, 35

Lamarckian Theory, 421

Lamarckism, 37

Late marriages, 218

Laws, eugenic, 196

Laws of heredity, 99

League to enforce peace, 328

Legal aspects, 194

Legislative aspects, 194

Leipzig, 321

Lethal chamber, 184

Lethal selection, 145

Levantines, 299

Lithuanians, 311

Living wage, 375

Longevity, 403

Loscin and Lascin, 314

Lunatics, 193

M

Macedonia, 326

Madonnas, 397

Maine, University of, 47

Mairet, 44

Malaria, 63

Malayans, 315

Malone, Widow, 204

Mamelukes, 284

Management, 221

Manchester, 57

Mann, Mrs. Horace, 153

Marks, school, 216

Marriage laws, 196

Marriage rate, 237

Marshall, Gov. Thomas R., 191

Martha's Vineyard, 154

Maryland, 206

Mass. Agricultural College, 255

Mass. State Prison, 182

Maternal impression, 64

Maternity, 221

Mean American man, 425

Mechanism of inheritance, 431

Medical colleges, 246

Mediterranean, 49, 52

Mediterranean race, 280, 357

Mendelian units, 105

Mendelism, essence of, 427

Mendelssohn, F. B., 96

Mental capacities, inheritance of, 84

Mental measurements, 75

Mesocephalic heads, 427

Mestizos, 314

Methodist clergymen, 270

Methods of restriction, 184

Metis, Spanish, 314

Meyerbeer, G., 96

Middle Atlantic states, 358

Middletown, Conn., 192

Military celibacy, 320

Minimum wage, 374

Miscegenation, 209, 291

Modesty, 251

Modification of the germ-plasm, 25

Mohammed, 179

Moral equivalent of war, 27

Moral perverts, 193

Moravians, 311

Mormon Church, 273

Mothers' pensions, 375, 376

Mother's age, influence of, 347

Motivated ethics, 394

Mountain states, 358

Mount Holyoke College, 240, 263

Movement, eugenic, 147

Mozambique, 129

Mulatto, 288

Multiple factors, 104

Music, 96

Mutation, 441

Mutilations, 38

N

Nashville, Tenn., 261

National army, 319

National association for the advancement of colored people, 294, 295

National committee for mental hygiene, 172

Native whites, 238

Natural inheritance, 152

Natural selection, 148

Nature, 1

Nebraska, 208

Negro women, 387

New Hampshire, 208

New Haven, Conn., 261

New Mexico, 187

Newport News, Va., 288

New world, 324

Nicolin, 45

Night-blindness, 109, 433

Nilsson-Ehle, H., 104

Nobility, 118

Normal curve, 441

Normal school girls, 262

Norman conquest, 338

Normandy, 338

North Carolina, 326

North Dakota, 193

North European, 426

North Italians, 427

Northern United States, 326

Norwich, Conn., 192

Nucleus, 441

Nurture, 1

O

Oberlin college, 244

Occupation, diseases of, 62

Ohio State University, 244

Organization of industry, 307

Oriental immigration, 313

Origin of eugenics, 147

Ovarian transplantation, 419

Ovize, 44

P

Pacific, 358

Paget parish, Bermuda, 205

Paraguay, 325

Parents of great men, 423

Partial segregation, 250

Past performance, 342

Passing of the great race, 426

Patent, definition of, 441

Paternity, 219

Pedagogical celibacy, 390

Peerage, 232

Pennsylvania Dutch, 424

Pennsylvania, feeble-minded citizens of, 168

Pennsylvania, University of, 132

Persians, 321

Perversion, 248

Pessimism, 247

Philanthropy, 33

Philippine islands, 313

Philippines, 324

Phthisis, 126

Physical care of the infant, 278

Physical culture, 219

Physico-chemical effects, 38

Piang, Datto, 314

Pikipitanges, 132

Pilgrim fathers, 424

Piney folk, 168

Pitcairn islanders, 300

Pittsburgh, 138

Pittsburgh, University of, 234

Pituitary gland, 103

Plymouth, England, 118

Polygamy, 387

Population, Malthusian, 151

Portland, Ore., 261

Possible improvement of the human breed, etc., 152

Pragmatic school, 352

Preferential mating, 214

Pre-natal care, 70

Pre-natal culture, 70

Pre-natal influence, 64

Pre-natal life, 155

Princeton college, 249

Proctor fellowship, 249

Production, 307

Professional classes, 232

Professor's families, 228

Progressive changes, 39

Prohibited degrees of marriage, 222

Prohibition, 389

Propaganda, eugenic, 195

Prophylaxis, 252

Prostitution, 251

Protestant Christianity, 274

Protoplasm, 442

Pseudo-celibacy, 248

Psychiatry, 442

Psychopathic inferiority, 302

Ptolemies, 206

Public charities association, 168

Punishment, 192

Punitive purpose, 192

Puritan, 298

Q

Quadruplets, Fig. I

Quaker families, 118, 144

Quakers, English, 411

R

Rabbits, 45

Race betterment conference, first, 1

Race suicide, 257

Rapists, 193

Reconstruction period, 325

Refraction, 59

Religion and eugenics, 393

Remote ancestors, 338

Research fellowship, 153

Reserve, 251

Restriction, methods of, 184

Restrictive eugenics, 175, 184

Retrogression, 42

Revolutionary war, 426

Reward and punishment, 395

Rhode Island, 261

Richmond, Va., 288

Roman catholic church, 273

Roman republic, 284

Rome custodial asylum, 186

Roosevelt, T., 308

Round-headed type, 427

Rubin, von Gruber and, 204

Russell Sage Foundation, 186

Russian Jews, 427

Russo-Hebrew, 302

Russo-Japanese war, 321

Ruthenians, 311

S

Sacerdotal celibacy, 222

St. Paul, public schools of, 372

Salpingectomy, 185

San Domingo, 289

Save the babies propaganda, 273, 412

Scandinavia, 299

Scandinavian, 311

Schoenberg, Berlin, 382

School acquaintance, 234

Scope of eugenics, 152

Scotland, 237

Selection, 442

Selection, natural, 148

Selective conscription, 320

Self-repression, 251

Sex determination, 347

Sex equality, 379

Sex ethics, 252

Sex histories, 252

Sex hygiene movement, 385

Sex hygienists, 154

Sex-limited, 442

Sex-linked, 442

Sex-linked characters, 433

Sexual perverts, 193

Sexual variety, 247

Shepherd's purse, 104

Short-fingerness, 102

Shorthorn cattle, 423

Short-sightedness, 12

Single tax, 353

Sing Sing, 182

Sixty family, 168

Smith's island, 206

Social status, 229

Socialism, 362

Solvay Institut, 155

Somerset parish, Bermuda, 205

South Atlantic, 358

South Carolina, 187

South Italians, 427

South Slavs, 302

Southern United States, 291, 325

Southwestern state normal school, 217

Spanish, 324

Spanish conquest, 131

Spanish wells, 203

Spartans, 171

Spermatozoa, 45

Spirochaete, 62

Standards of education, 275

Stanford University, 245

State Board of Charities of New York, 435

Station for Experimental Evolution, 100

Sterilization, 185

Stuart line, 19

Subordination of women, 362

Substitution tests, 288

Superficial characteristics, 227

Superior, marriage rate of, 237

Superiority of eldest, 344

Symphalangism, 433, Fig. 17

Syphilis, 63

Syphilitics, 193

Syracuse University, 245

T

Tail-male line, 331

Talent, hereditary, 151

Taxation, 352

Telegony, 73

Ten commandments, 394

Tennessee, 187

Teutonic, 426

Teutonic nations, 52

Theistic religion, 395

Theognis of Megara, 150

Therapeutic, 192

Thirty Years' war, 326

Threadworn, 7

Trades unionism, 388

Training school of Vineland, N. J., 188

Transmissibility, 38

Tropical fevers, 133

Tropics, 35

Turkish, 311

Turpitude, moral, 194

U

Unfitness, 121

Unit-character, 443

U. S. public health service, 303

University of London, 153

University of Pittsburgh, 216

Unlike, marriage of, 212

Uruguay, 325

Use and disuse, 38

Useful works of reference, 435

Uterine infection, 38

V

Vagrants, 302

Variation, 443

Variate difference correlation, 121

Vasectomy, 184

Vassar College, 240

Venereal diseases, 248, 251

Venereal infection, 386

Vermont, 326

Vestigial, 443

Victor Emmanuel, 19

Vineyard, Martha's, 154

Virginia, 326

Vision, 59

Vocational guidance, 371

Vocational training, 371

Volta bureau, 154

W

Washington, G., 337

Washington Seminary, 242

Weakness, matings involving, 200

Wedgewood, E., 208

Wellesley scholarships, 262

West north central states, 358

West south central states, 358

West Virginia, 187

Westergaard, H., 57

White slavery, 193

William the Conqueror, 338

William of Occam, 93

William of Orange, 19

William the Silent, 19

Wisconsin, University of, 45, 63, 244

Woman suffrage, 380

Woman's colleges, 383

Y

Young Men's Christian Association, 155, 235, 336

Young Peoples Society of Christian Endeavor, 234

Young Women's Christian Association, 235

Z

Zero Family, 168

Zymotic, 443

FOOTNOTES

See Woods, Frederick Adams, "Laws of Diminishing Environmental Influences," Popular Science Monthly, April, 1910, pp. 313-336; Huxley, J. S., The Individual in the Animal Kingdom, Cambridge and New York, 1912. Pike, F. H., and Scott, E. L., "The Significance of Certain Internal Conditions of the Organism in Organic Evolution," American Naturalist, Vol. XLIX, pp. 321-359, June, 1915.

There is one line of experiment which is simple and striking enough to deserve mention--namely, ovarian transplantation. A description of this is given in Appendix A.

Galton, Francis, Inquiries into Human Faculty, 1907 edition, pp. 153-173. This volume of Galton's, which was first published in 1883, has been reissued in Everyman's Library, and should be read by all eugenists.

What is said here refers to positive correlations, which are the only kind involved in this problem. Correlations may also be negative, lying between 0 and -1; for instance, if we measured the correlation between a man's lack of appetite and the time that had elapsed since his last meal, we would have to express it by a negative fraction, the minus sign showing that the greater his satiety, the less would be the time since his repast. The best introduction to correlations is Elderton's Primer of Statistics (London, 1912).

Dr. Thorndike's careful measurements showed that it is impossible to draw a hard and fast line between identical twins and ordinary twins. There is no question as to the existence of the two kinds, but the ordinary twins may happen to be so nearly alike as to resemble identical twins. Accordingly, mere appearance is not a safe criterion of the identity of twins. His researches were published in the Archives of Philosophy, Psychology and Scientific Methods, No. 1, New York, 1905.

A First Study of the Inheritance of Vision and the Relative Influence of Heredity and Environment on Sight. By Amy Barrington and Karl Pearson. Eugenics Laboratory (London), Memoir Series V.

Dr. James Alexander Wilson, assistant surgeon of the Opthalmic Institute, Glasgow, published an analysis of 1,500 cases of myopia in the British Medical Journal, p. 395, August 29, 1914. His methods are not above criticism, and too much importance should not be attached to his results, which show that in 58% of the cases heredity can be credited with the myopia of the patient. In 12% of the cases it was due to inflammation of the cornea (keratitis) while in the remaining 30% no hereditary influence could be proved, but various reasons made him feel certain that in many cases it existed. The distribution of myopia by trades and professions among his patients is suggestive: 65% of the cases among school children showed myopic heredity; 63% among housewives and domestic servants; 68% among shop and factory works; 60% among clerks and typists; 60% among laborers and miners. If environment really played an active part, one would not expect to find this similarity in percentages between laborers and clerks, between housewives and schoolteachers, etc.

The Influence of Unfavourable Home Environment and Defective Physique on the Intelligence of School Children. By David Heron. Eugenics Laboratory (London), Memoir Series No. VIII.

Hereditary Genius; an Inquiry into its Laws and Consequences. London, 1869.

Woods, Frederick Adams, "Heredity and the Hall of Fame," Popular Science Monthly, May, 1913.

Woods, Frederick Adams, Mental and Moral Heredity in Royalty, New York, 1906. See also "Sovereigns and the Supposed Influence of Opportunity," Science, n. s., XXXIX, No. 1016, pp. 902-905, June 19, 1914, where Dr. Woods answers some criticisms of his work.

Educational Psychology, Vol. III, p. 306. Starch's results are also quoted from Thorndike.

Jean Baptiste Lamarck, a French naturalist, born in 1744, was one of the pioneers in the philosophical study of evolution. The theory (published in 1809) for which he is best known is as follows: "Changes in the animal's surroundings are responded to by changes in its habits." "Any particular habit involves the regular use of some organs and the disuse of others. Those organs which are used will be developed and strengthened, those not used diminished and weakened, and the changes so produced will be transmitted to the offspring, and thus progressive development of particular organs will go on from generation to generation." His classical example is the neck of the giraffe, which he supposes to be long because, for generation after generation, the animals stretched their necks in order to get the highest leaves from the trees.

Boas, F., Changes in Body Form of Descendants of Immigrants, 1911.

Civilization and Climate. By Ellsworth Huntington, Yale University Press, 1916.

Dr. Reid is the author who has most effectively called attention to this relation between alcohol and natural selection. Those interested will find a full treatment in his books, The Present Evolution of Man, The Laws of Heredity, and The Principles of Heredity.

Principles of Psychology, ii, p. 543.

Leon J. Cole points out that this may be due in considerable part to less voluntary restriction of offspring on the part of those who are often under the influence of alcohol.

For a review of the statistical problems involved, see Karl Pearson. An attempt to correct some of the misstatements made by Sir Victor Horsley, F. R. S., F. R. C. S., and Mary D. Sturge, M. D., in their criticisms of the Galton Laboratory Memoir: First Study of the Influence of Parental Alcoholism, etc.; and Professor Pearson's various popular lectures, also A Second Study of the Influence of Parental Alcoholism on the Physique and Intelligence of Offspring. By Karl Pearson and Ethel M. Elderton. Eugenics Laboratory Memoir Series XIII.

A First Study of the Influence of Parental Alcoholism on the Physique and Intelligence of Offspring. By Ethel M. Elderton and Karl Pearson. Eugenics Laboratory Memoir Series X. Harald Westergaard, who reexamined the Elderton-Pearson data, concludes that considerable importance is to be attached to the selective action of alcohol, the weaklings in the alcoholic families having been weeded out early in life.

Prohibition would have some indirect eugenic effects, which will be discussed in Chapter XVIII.

Chapter XXX, verses 31-43. A knowledge of the pedigree of Laban's cattle would undoubtedly explain where the stripes came from. It is interesting to note how this idea persists: a correspondent has recently sent an account of seven striped lambs born after their mothers had seen a striped skunk. The actual explanation is doubtless that suggested by Heller in the Journal of Heredity, VI, 480 (October, 1915), that a stripe is part of the ancestral coat pattern of the sheep, and appears from time to time because of reversion.

Such a skin affection, known as icthyosis, xerosis or xeroderma, is usually due to heredity. Davenport says it "is especially apt to be found in families in which consanguineous marriages occur and this fact, together with the pedigrees [which he studied], suggests that it is due to the absence of some factor that controls the process of cornification of the skin. On this hypothesis a normal person who belongs to an affected family may marry into a normal family with impunity, but cousin marriages are to be avoided." See Davenport, C. B., Heredity in Relation to Eugenics, p. 134. New York, 1911.

Its eugenics is to be effected through the mental exertion of mothers. And we have lately been in correspondence with a western attorney who is endeavoring to form an association of persons who will agree to be the parents of "willed" children. By this means, he has calculated (and sends a chart to prove it) that it will require only four generations to produce the Superman.

Life and Letters of Charles Darwin, Vol. I, p. 302, New York, 1897. The letter is dated 1844.

Goddard, H. H., Feeble-mindedness, p. 359. New York, the Macmillan Company, 1914.

For a review of the evidence consult an article on "Telegony" by Dr. Etienne Rabaud in the Journal of Heredity, Vol. V, No. 9, pp. 389-400; September, 1914.

It will be recalled that the coefficient of correlation measures the resemblance between two variables on a scale between 0 and-1 or +1. If the correlation is zero, there is no constant relation; if it is unity, any change in one must result in a determinate change in the other; if it is 0.5, it means that when one of the variables deviates from the mean of its class by a given amount, the other variable will deviate from the mean of its class by 50% of that amount (each deviation being measured in terms of the variability of its own class, in order that they may be properly comparable.)

Sidis, Boris, M.A., Ph.D., M.D., "Neurosis and Eugenics," Medical Review of* *Reviews, Vol. XXI, No. 10, pp. 587-594, New York, October, 1915. A psychologist who writes of "some miraculous germ-plasm (chromatin) with wonderful dominant 'units' (Chromosomes)" is hardly a competent critic of the facts of heredity.

In a letter to the Journal of Heredity, under date of August 4, 1916.

Galton, Francis, Inquiries into Human Faculty, p. 167, London, 1907.

Woods, Frederick Adams, Heredity in Royalty, New York, 1906.

Thorndike, E. L., "Measurements of Twins," Arch. of Philos., Psych. and Sci. Methods, No. 1, New York, 1905; summarized in his Educational Psychology, Vol. III, pp. 247-251, New York, 1914. Measured on a scale where 1 = identity, he found that twins showed a resemblance to each other of about .75, while ordinary brothers of about the same age resembled each other to the extent of about .50 only. The resemblance was approximately the same in both physical and mental traits.

The quotations in this and the following paragraph are from Thorndike's Educational Psychology, pp. 304-305, Vol. III.

"William of Occam's Razor" is the canon of logic which declares that it is unwise to seek for several causes of an effect, if a single cause is adequate to account for it.

Educational Psychology (1914), Vol. III, p. 235.

Cobb, Margaret V., Journal of Educational Psychology, viii, pp. 1-20, Jan., 1917.

This is not true of the small English school of biometrists, founded by Sir Francis Galton, W. F. R. Weldon and Karl Pearson, and now led by the latter. It has throughout denied or minified Mendelian results, and depended on the treatment of inheritance by a study of correlations. With the progress of Mendelian research, biometric methods must be supplemented with pedigree studies. In human heredity, on the other hand, because of the great difficulties attendant upon an application of Mendelian methods, the biometric mode of attack is still the most useful, and has been largely used in the present book. It has been often supposed that the methods of the two schools (biometry and Mendelism) are antagonistic. They are rather supplementary, each being valuable in cases where the other is less applicable. See Pearl, Raymond, Modes of Research in Genetics, p. 182, New York, 1915

Few people realize what large numbers of plants and animals have been bred for experimental purposes during the last decade; W. E. Castle of Bussey Institution, Forest Hills, Mass., has bred not less than 45,000 rats. In the study of a single character, the endosperm of maize, nearly 100,000 pedigreed seeds have been examined by different students. Workers at the University of California have tabulated more than 10,000 measurements on flower size alone, in tobacco hybrids. T. H. Morgan and his associates at Columbia University have bred and studied more than half a million fruit flies, and J. Arthur Harris has handled more than 600,000 bean-plants at the Carnegie Institution's Station for Experimental Evolution, Cold Spring Harbor, L. I. While facts of human heredity, and of inheritance in large mammals generally, are often grounded on scanty evidence, it must not be thought that the fundamental generalizations of heredity are based on insufficient data.

For a brief account of Mendelism, see Appendix D.

Of course these factors are not of equal importance; some of them produce large changes and some, as far as can be told, are of minor significance. The factors, moreover, undergo large changes from time to time, thus producing mutations; and it is probable small changes as well, the evidence for which requires greater refinements of method than is usual among those using the pedigree method.

A Critique of the Theory of Evolution, by Thomas Hunt Morgan, professor of experimental zooelogy in Columbia University. Princeton University Press, 1916. This book gives the best popular account of the studies of heredity in Drosophila. The advanced student will find The Mechanism of Mendelian Heredity (New York, 1915), by Morgan, Sturtevant, Mueller, and Bridges, indispensable, but it is beyond the comprehension of most beginners.

"On the Inheritance of Some Characters in Wheat," A. and G. Howard, Mem. Dep. of Agr. India, V: 1-46, 1912. This careful and important work has never received the recognition it deserves, apparently because few geneticists have seen it. While the multiple factors in wheat seem to be different, those reported by East and Shull appear to be merely duplicates.

"The Nature of Mendelian Units." By G. N. Collins, Journal of Heredity, V: 425 ff., Oct., 1914.

Dr. Castle, reviewing Dr. Goddard's work (Journal of Abnormal Psychology, Aug.-Sept., 1915) concludes that feeble-mindedness is to be explained as a case of multiple allelomorphs. The evidence is inadequate to prove this, and proof would be, in fact, almost impossible, because of the difficulty of determining just what the segregation ratios are.

In strict accuracy, the law of ancestral inheritance must be described as giving means of determining the probable deviation of any individual from the mean of his own generation, when the deviations of some or all of his ancestry from the types of their respective generations are known. It presupposes (1) no assortative mating, (2) no inbreeding and (3) no selection. Galton's own formula, which supposed that the parents contributed 1/2, the grandparents 1/4, the great-grandparents 1/8, the next generation 1/16, and so on, is of value now only historically, or to illustrate to a layman the fact that he inherits from his whole ancestry, not from his parents alone.

Johnson, Roswell H., "The Malthusian Principle and Natural Selection," American Naturalist, XLVI (1912), pp. 372-376.

Karl Pearson, The Groundwork of Eugenics, p. 25, London, 1912.

"Let p be the chance of death from a random, not a constitutional source, then 1-p is the chance of a selective death in a parent and 1-p again of a selective death in the case of an offspring, then

Archiv f. Rassen-u. Gesellschafts Biologie, VI (1909), pp. 33-43.

Snow, E. C., On the Intensity of Natural Selection in Man, London, 1911.

Pearson, Karl, Tuberculosis, Heredity and Environment, London, 1912. Among the most careful contributions to the problem of tuberculosis are those of Charles Goring (On the Inheritance of the Diathesis of Phthisis and Insanity*, London, 1910), Ernest G. Pope (*A Second Study of the Statistics of Pulmonary Tuberculosis, London, Dulau & Co.), and W. P. Elderton and S. J. Perry (A Third Study of the Statistics of Pulmonary Tuberculosis. The Mortality of the Tuberculous and Sanatorium Treatment), London, 1909. See also our discussion in