as some equivalent to the loss of what it forbids. It brings the tie of kinship into prominence and strongly encourages love in family and race. In brief, eugenics is a virile creed, full of hope, and appealing to many of the noblest feelings of our nature." 5

In the earlier history of the human race natural selection through a struggle for existence worked a survival of the fittest. The fit were successively those of brute strength, cunning and intelligence. The fittest is he who combines the three in proper proportions. A later evolution superposed the soul, or the ethical sense. With the birth of morals came humanitarian sentiments. Charity has counteracted the beneficent influence of natural selection. Promiscuous and unguided by scientific wisdom it works for a condition of reversed selection. It favours the unfit at the expense of the fit. Eugenics would take no backward step; it could not countenance abandonment of rational charity; but it must somehow neutralise the dysgenic effect of misguided emotional charity.

Do you realise that only about 12 per cent. of the present generation, that is only about 25 per cent. of the marriages of a period, produce 50 per cent. of the next? I need but ask the question, "Who constitutes this 12 per cent.?" You well know it is not preponderatingly our racial best. Our nation is in peril to the extent that this includes the unfit whom eleemosynary activities carefully shield and produce. Do you realise that about 10 per cent. of our population is defective, an economic and social burden, and a constant source of racial menace and contamination? Only about 1

5 Essays in Eugenics, V: Eugenics as a Factor in Religion, p. 70.

per cent. of this portion is in institutions where any effort whatever can be made to prevent reproduction of this type. Only about 10 per cent. of all feeble-minded are in institutions or can be and the feebleminded are the race's gravest source of injury. Do you realise that the fecundity of defectives is at least about twice as great as that of the average of our population? And as to the intellectual classes, Oxford graduates barely numerically reproduce themselves, and Harvard graduates do but little better.

In New England many of the old family names are dying out by reason of decrease in the number of offspring and the scarcity or total absence of males in the later generations. One family of which I have the data from the year 1610, given me by the last adult male member, will suffice for illustration: The data include 10 generations. In the first three, males were produced in excess in the proportion of 9 to 7; in the succeeding six, females were produced in excess in the proportion of 22 to 15. The average number of births per generation is approximately 6; but in the last four generations there is a sharp and regular decline from 9 to 5 to 3 to 2. The last generation includes 7 females and I male.

On the basis of Davenport's work on epilepsy in New Jersey, we know that the number of epileptics doubles every thirty years. It seems very clear then if present conditions continue the Anglo-Saxon race is eventually doomed. What remedy does eugenics offer? And what are the scientific data upon which its proposals rest?

Davenport and Weeks. Eugenics Record Office Bull. No. 4, 1911.

For illustration of the working of Mendelian inheritance, upon which eugenics so heavily rests, I shall take the case of use of the hand. This involves a brief discussion of how we probably came to be right-handed. The early representatives of the race, the Neanderthal men for sake of concrete instance, were probably ambidextrous, i.e., they used either hand equally well for all manipulation. The child, recapitulating its racial history, is ambidextrous until somewhere about the seventh month. The race and the child become either left-handed or right-handed or in a few cases may remain ambidextrous. However, what is ordinarily called ambidexterity in the adult is more probably lefthandedness superposed on which is acquired righthandedness. We shall not here inquire how fundamentally right-handedness arose. Once arisen those who could not conform perhaps largely perished by natural selection. From those who varied in the lefthanded direction, and escaped elimination, present lefthanded individuals have probably come. Left-handedness and right-handedness may be considered alternative or unit characters in the Mendelian sense. In the germ-plasm of the one may be said to be the determiners for left-handedness; in that of the other for right-handedness. In terms of presence and absence, to which scheme the majority of Mendelian characters appear to conform, right-handedness may be conceived as dependent upon the presence of the determiner in the germ-plasm, left-handedness and ambidexterity as the result of its absence. But right

7 See "The Inheritance of Lefthandedness." American Breeders' Magazine, 1911; also "Studies in Human Heredity," Bull. Phil. Soc. University of Virginia, 1912.

handed individuals are of two sorts, those both of whose parents were right-handed, and those with only one parent right-handed. The former are said to be of the duplex, the latter of simplex condition. Those with both parents left-handed i.e., lacking the determiner for right-handedness are said to be nulliplex. The right-handed condition dominates or masks the left-handed condition in the hybrid generation. When left-handed mate with left-handed all the children will be left-handed. When the determiner for a character is absent from the germ-plasm of the parent, that character cannot appear in the body of the offspring. When simplex mate with simplex, one in every four will be left-handed. This is the well-known 1 to 3 Mendelian ratio for hybrid crosses with respect to a particular pair of unit characters. When simplex mate with nulliplex one-half of the offspring will lack the determiner for right-handedness and be left-handed.

In the classical experiments of Mendel with peas the results are still more certain and clear. And they have been verified in the case of many instances in animals. and man. The example of blue and brown eyes worked out by Professor C. B. Davenport in this country, and by Major C. C. Hurst in England, is especially striking and conclusive. The above given ratio of 1 to 3 for crosses of simplex hybrids and 1 to 1 for simplex with nulliplex cross could result only if the special condition were fulfilled with respect to the determiners of the pair of contrasting characters, namely, that they be contained in separate germ-cells. That is, no germ-cell, either male or female, could contain both

⚫ Science, 1907, vol. 26, p. 589. Nature, 1907, vol. 76, p. 558.

the determiner for left-handedness and for righthandedness or, in conformity with the presence and absence hypothesis only one-half of each class of germcells could contain the determiner. Then assuming a random mixture of such germ-cells from hybrid male and female there would be one chance of a germ-cell with a left-handed determiner meeting one of its kind, to one with a right-handed determiner meeting one of its kind, to two chances of a germ-cell with a righthanded determiner meeting one with a left-handed determiner. Again the law of chance under the altered condition of simplex crossing with nulliplex will give the one to one ratio. The foregoing discussion has dealt with the three central concepts of Mendelian inheritance; 1) unit characters, i.e. such as apparently defy further analysis and comport themselves as units in inheritance; 2) dominance, by virtue of which one of a pair of alternative characters dominates or masks the other in the first hybrid generation; 3) segregation, producing a purity of germ-cells with respect to a particular pair of unit characters. Pure dominants and pure recessives always breed true. Hybrids interbred always produce dominants and recessives in the proportion of 1 pure dominant to 2 hybrid dominants to I pure recessive. This may on first hearing seem very complicated. The significant fact is that definite law underlies human possibilities for development. Chance is restricted to a limited number of possible combinations of the biparental stock of unit characters.

At least several score of human traits, physical, mental and pathological are now thought by some to conform more or less closely to this scheme. There is