a family group of 477 individuals, representing seven generations. The younger members are still a serious problem in the life of their community. In another county is a family group of 152 individuals, notorious not only for shiftlessness and immorality, which so often characterize these records, but also for crime. Fourteen of its members have police court records, three have been convicted for serious crimes, one has been in a reform school. The writer once had ranged before him in a county poor asylum four feebleminded persons: a man, his daughter, granddaughter and great grandson,-four generations, all living at public expense. Thirty years ago a young feebleminded woman was admitted to one of our county poor asylums. A year later a blind man became an inmate. The two became acquainted and in time were married. Their wedding occurred in the poor asylum, they set up their family altar there and to them were born five children, all in the institution. Quite recently one of their daughters was committed to the woman's prison for perjury, in connection with statements concerning her illegitimate child, who is now in an orphan's home. In this case, as not infrequently happens, public officials connived at that which later brought a heavy burden of expense and disgrace upon their community. They "knew not, and knew not that they knew not." One could fill a book with these Indiana stories of misery and degradation, of sin and suffering and crime, of public ignorance, indifference and neglect. And they could doubtless be duplicated in every state in the Union. Everywhere our people have failed to realize what was happening and these weaker children of the land have grown incredibly strong in numbers and in power for evil. More than once I have taken occasion to say that feeblemindedness is one of the most potential destructive factors in our civilization. It produces more pauperism, more crime, more degeneracy, than any other one force. It is a fact we have to face, a condition we have to meet, a power we must keep under. INHERITANCE OF MENTAL DISORDERS* By AARON J. ROSANOFF, M.D. ✔ Clinical Director, Kings Park State Hospital, Kings Park, L. I., N. Y. The object of this communication is to present a summary of the more important known facts concerning the inheritance of mental disorders and to attempt a synthetic treatment of them. Mental disorders consist of a series of more or less sharply defined clinical entities in the causation of which variable relative parts are played, respectively, by inborn and environmental factors. Numerically the most important group consists of those disorders which have, by a sort of common consent, been designated constitutional, the implication being that the inborn factors play an essential part in their causation. It is with this group that my paper deals. The principal clinical entities included are: mental deficiency, epilepsy, dementia praecox, paranoia, manic-depressive psychoses, psychoneuroses, and psychopathic personalities. A more detailed classification of them is given in the following chart: 骨 Manic-depressive psychoses.. depressed form manic form mixed and alternating forms involutional forms Read before the Section on Human and Comparative Heredity of the Second International Eugenics Congress, New York City, September 24, 1921. Psychoneuroses. Psychopathic personalities.. hysteria psychasthenia inadequate personality criminalism pathological lying Institutional experience shows that the constitutional mental disorders run in families, and special statistical studies point to heredity as being the origin of psychopathic constitutions (1, 2, 3). The latter fact is to-day no longer in question; but there is considerable difference of opinion as to the relative amounts of causation attributable to heredity and to other factors. The obvious reason for this difference of opinion lies in our inability to measure exactly the factors involved. Rough measurements are, however, possible; and accumulated evidence seems to be to the effect that the relative importance of the factor of heredity varies in individual cases, firstly, with the clinical subdivision, and, secondly, within each subdivision, with age of onset, amount of demonstrable external cause, intensity of manifestations, their intractableness or persistence in spite of treatment, etc. Thus, mental deficiency and, to a lesser extent, epilepsy are subdivisions in which heredity alone in most cases determines the manifestations. On the other hand, psychoneuroses, especially hysteria, most often develop in reaction to special external situations, being, under usual conditions, latent. Other subdivisions hold, in this respect, intermediate positions. Within the same subdivision, say that of dementia praecox, are found, on the one hand, cases which present abnormal psychic traits all through childhood, onset of grave psychotic symptoms at puberty or before in the absence of pathogenic environmental influences, and rapid passage into chronicity and deterioration in spite of all efforts of treatment; and on the other hand, cases in men of apparently normal psychic make-up, who, perhaps at middle age, following financial and marital troubles, take to heavy drinking and develop an acute hallucinosis or some other schizophrenic episode, which subsides under no other treatment than a few days' rest in a hospital. A highly significant fact is that of frequently observed atavistic heredity: after one or more generations in direct line of descent have been skipped, an ancestral mental disorder reappears, sometimes affecting two or more individuals in a sibship. From a Mendelian standpoint this is, of course, suggestive of recessiveness in relation to normal mental constitution. This seems to be true of all constitutional mental disorders, regardless of variety, with the possible exception of the manic form of manic-depressive psychoses (4, 5, 6, 7). Another significant fact is that of dissimilar heredity. All psychopathic members of a given family do not necessarily suffer from the same clinical form of mental disorder. More often than not they differ from one another either qualitatively, i. e., in respect of clinical variety, or quantitatively, i. e., in respect of severity of the disorder (8, 9, 10, 11, 12). one. The manner of distribution of the different clinical varieties of mental disorders in a family is apparently not a random Many studies have resulted in the observation that, although manic-depressive ancestors not infrequently have dementia praecox descendants, the reverse is very rare (13, 14, 15, 16). Based upon this and other similar observations a theory has been suggested, according to which the various psychopathic conditions possess different degrees of recessiveness and may be ranged in a scale of dominance in the following order: normal condition, manic-depressive psychoses, dementia praecox, epilepsy (7, 11). The fact of some sort of relationship of the clinically distinguished entities to one another is suggested not only by family studies, but also by the existence of transitional and borderline cases presenting mixed manifestations: dementia praecox with epileptiform convulsions; manic-depressive psychoses with an admixture of catatonic, delusional, hallucinatory, or other schizophrenic symptoms; psychoneuroses with occasional elated or depressed spells, etc. (11, 17, 18, 19, 20). The exact definition and measurement of the several clinical entities are rendered difficult by the fact of the great variations in their manifestations in different cases and in the same case at different times. These variations are spoken of among medical men as equivalents. Progress in psychiatry in the past two or three decades has been marked by a simplification of classification through a far reaching extension of the conception of clinical equivalents; and it would seem that a further extension of this conception is indicated by new accumulations of material (7). What bearing has our accumulated knowledge of the part played by heredity in the production of mental disorders on applied eugenics? Would there be justification in advocating restriction of propagation in all cases in which signs of constitutional mental disorder can be definitely established? In this connection it is sometimes forgotten that the aim of eugenics is not only to prevent the propagation of socially undesirable traits, but also to conserve and stimulate the propagation of socially desirable ones. The great majority of individuals, insane as well as sane, present combinations of desirable and undesirable traits in endless variety. A general judgment seems hardly possible; each case must receive special consideration. The presence of a mental disorder in gravest degree is not incompatible with intellectual activity of the highest order and value to society, as is witnessed by the cases of Jean Jacques Rousseau, Gustave Flaubert, William Cowper, Auguste Comte, Julius Robert Mayer, Feodor Dostoyevski, and many others (21). Moreover, judgment as to desirability or undesirability of a given trait is apt to vary in different countries, or parts of countries, or, in the same country, at different times, depending on type of civilization and prevailing social ideals and standards. It would seem to be a part of a healthy conservatism to refrain from the employment of any eugenic measure which is irrevocable-such as sterilization-at least for the present. Against segregation, on the other hand, there is no such objec |