country, even if no more drastic action is taken. Otherwise the group is bound to be an increasing burden on the community, adding constantly to the tax needed for their

support.

Investigations of competent officials in the employ of insane hospitals have accumulated a mass of evidence demonstrating the heritability of many forms of nervous diseases which most commonly behave as recessives. Rosanoff and Orr, in a study of 206 matings

FIG. 100.-(1) Ignorant, "queer"; (2) Insane, was in sanitarium, committed suicide; (3) eccentric, violent temper, ideas of persecution against neighbors; (4) eccentric, not well balanced; (5) alcoholic, lazy, indolent; state hospital; (7) violent temper, (6) dementia praecox, paranoid, in queer, extreme dolichocephaly; (8) defective, cranial malformation; (9) inferior, "slow." (From Downing, after Rosanoff and Orr.)

between individuals from more or less insane stock, found 1,097 children, 146 of whom died in childhood. There were 351 afflicted offspring to 586 normal. The theoretical expectations, knowing with more or less certainty the character of the parents, were 359 to 578. There are presented (Figs. 100, 101) two typical family pedigrees. In the first an insane man was twice married, each time to an

FIG. 101. (1) epileptic; (2) insane for a time, recovered; (3) epileptic, imbecile; (4) imbecile; (5) melancholy in early married life, recovered; (6) insane five years, was in state hospital, recovered; (7) insomnia, neuralgia; (8) daughter had spells of excitement; (9) feeble-minded; (10) dementia praecox, katatonic, in state hospital; (11) died of marasmus, had one convulsion. (From Downing, after Rosanoff and Orr.)

eccentric woman, undoubtedly mildly insane. All the offspring were unbalanced. In the second case, those distinctly neurotic are indicated in solid color; those having a neurotic element in the germ material are shaded. It might seem as if insane individuals would scarcely add materially to the general population, since they are commonly in asylums. Often, however, the inherited insanity does not 'Eugenics Record Office (Cold Springs Harbor, N.Y.) Bulletin No. 5, 1911.

manifest itself until past middle life, when they have already married and started a family. Moreover, those hybrid individuals in whom the insane tendency is present alongside of the normal determiner appear as normal individuals. Frequently they can be detected only by an examination of the pedigree. If such individuals mate, onefourth of the offspring would be expected to be insane.

Early modern European history centers about the doings of a few great men and women. Peter the Great of Russia, Ferdinand and Isabella and Charles V of Spain, Frederick the Great of Prussia, Gustavus Adolphus and Charles XII of Sweden, are among the most brilliant of these potent individuals that shaped the destinies of Europe during this period. It is interesting to note how their characters are determined (and through them national destinies are apparently decided in no small measure) by the hereditary concentration of ability due to lucky royal matings, and how their genius is dissipated by unwise matings.

Peter the Great of Russia came as a brilliant type from a good stock, though with a very evident taint of epilepsy and feeblemindedness. He himself was an epileptic. His father, grandfather, and great-grandfather had been men of large ability. They had married peasant girls, as was the custom of the czars. Peter's own brothers and sisters were in no way remarkable. His half-sister Sophia was a woman of marked ability, although two of her brothers were imbeciles, one also an epileptic. As will be seen from the pedigree, the epilepsy, imbecility, and mediocrity appear in both Peter's children and grandchildren, as well as in those of his imbecile half-brother, Ivan. It is interesting to note from the pedigree that the feeble-mindedness and epilepsy seem to cling to the males quite persistently. The females of the family are much more apt to be brilliant and virtuous. Peter the Great's own son Alexis was a poor dissolute specimen, and although he married Charlotte, the angelic daughter of a great line, the house of Brunswick, the son of this mating was Peter II, of unstable mind, while the daughter Natalia was as sweet as she was energetic.

Isabella and Ferdinand were both descendants from lines of very great individuals, although in each case there is insanity in the family. Isabella herself comes from an insane mother and an imbecile father, but her grandparents and great-grandparents were well-balanced and able. The data for the charts of these royal families were taken largely from F. A. Woods's Mental and Moral Heredity in Royalty, supplemented with information from other sources. He grades the

individuals on a scale of 10. Ten represents very high ability, as determined by the comparative amount of space and laudation given to the individual in such standard works as Lippincott's Biographical Dictionary. Five out of eight of Isabella's great-grandparents rank very high. John the Great of Portugal, twice her great-grandfather, has a grade of 10. John of Gault, twice her great-grandfather, has a grade of 8, as does also John of Castile, while Henry III of Castile, one of her grandparents, is designated the model king. Ferdinand I of Aragon, the grandfather of Ferdinand, is a brother of this same Henry III of Castile, and is also an exceedingly able king. Of the children of Ferdinand and Isabella, most were mediocre or distinctly inferior. Joanna was insane. In the next generation, however, appears Charles V, whose reign marked the acme of Spain's greatness, partially due to his own ability, partially due to the momentum of those movements that were instituted by his illustrious grandparents. Charles V married his own cousin, as did also John III. Children of these two matings married, and Don Carlos, child of this latter marriage, was madly depraved and cruel.

When insanity and brilliancy are found in the ancestry it seems merely a matter of chance as to whether the determiners for greatness will be thrown together in the union of sperm and egg or those for insanity. We can predict with some certainty, that, in a large number of offspring, ability will reappear and insanity will reappear, but just what individual each will strike it is impossible to prophesy without knowing much more definitely the nature of the germ plasm involved. One may say that the convergence of a number of lines of descent from great ancestors toward one individual makes it probable that he will be exceptionally able.

This is nowhere better illustrated than in the family tree of Frederick the Great of the Prussian house of Hohenzollern, as will be seen from the chart on page 470. Of his great-grandparents, three scale 10, one 9, one 8, two 7, and one 6. Not one is below mediocrity, and the majority are of very high grade. Of his fourteen ancestors back three generations, only one is distinctly inferior. Of his brothers and sisters, four are distinctly great, three mediocre, and one inferior.

It is interesting to trace the effect of the mating of such splendid stock with another brilliant line, that of the Swedish royal house. Gustavus I, or Gustavus Vasa, is another instance of the brilliant mutant, with some taint of neurosis. He married a gentle and tactful princess; their son Charles IX was a very able man, although of their