Part 12

Heredity is a very vexed question, with regard to which most varied opinions are held even by those apparently justified in having opinions, so that it is evident we are as yet only crossing the threshold of definite knowledge and are not near anything like the clear view that many people have imagined. The most striking proof of this inchoateness of scientific knowledge of heredity is the fact that within five years the work of a monk in Austria, done about forty years ago, which has lain utterly unrecognised ever since, has come to be accepted as the most striking bit of progress made--almost the only real scientific knowledge with regard to heredity that was acquired during the whole nineteenth century. Father Gregor Mendel's work [Footnote 2] was done with regard to the pea plants in his monastery garden, and it revolutionised all the supposedly scientific thinking with regard to heredity that has been current in biology for half a century.

[Footnote 2: _See American Ecclesiastical Review_, Jan. 1904; Walsh, _A New Outlook in Heredity_. ]

This serves very well to show how far in advance of observed facts theories of heredity have gone. There is undoubtedly a very significant influence exerted over life and its functions by the special powers that are transmitted by heredity. How far this influence extends, however, and how much it may be said to rule details of existence, of action and in human beings, that complex of elements we call character, is entirely a matter of conjecture, and the {121} belief in its extent, or limitation, depends absolutely on the tendency of the individual mind to accept or discredit certain theories in heredity which have had great vogue.

Until within a very few years it was considered a matter of common experience and observation that under some circumstances, at least, acquired characteristics were transmitted by heredity. That is to say, it has been definitely asserted as probable, and by many even intelligent people considered absolutely certain, that modifications of a living being undergone during the course of its existence might influence the progeny of that being in various but very definite ways. It was not, of course, thought that if a man lost an arm and subsequently begot a child, the child would be born without an arm, but slighter modifications of the organism were somehow supposed to be transmissible; and, on the other hand, modifications which affect important organic structures of the body were somehow thought to have a definite effect, by transmission, upon corresponding portions of the progeny.

When this theory is stated thus baldly, very few people confess their belief in it, yet how many there are who find ample justification for such expressions as, "His father suffered from rheumatism and it is not surprising then that he should have it"; "Her mother had heart trouble and we've always been afraid she would suffer in the same way." We are only just beginning to get beyond the period in which consumption was thought to be directly and almost inevitably inherited. With regard to mental ailments this was frankly conceded by nearly every one. If the direct ancestry suffered from mental disease of some kind, then it is not considered surprising that the immediate descendants should be mentally affected in some way. Physicians are quite as prone as those without medical training to make loose statements of this kind.

Of course there is a reason for the confusion that exists in this matter. Oliver Wendell Holmes once said that he could cure any patient that came to him for treatment, if he but applied to him in time. For proper success, however, he considered that many of his patients would have had to come to him in the persons of their great grandfathers. As {122} a matter of fact, many of the supposed hereditary influences that are traced only to a father or a mother are family conditions that have existed many generations, and that were probably originally acquired, but the moment of whose acquisition cannot be definitely determined. We know that the Hapsburg lip has been a distinguishing feature, a persistently recurring peculiarity, in some of the members of the Austrian ruling family in nearly every generation for seven centuries. How much farther back than that it goes we have no way of determining. It is a family affair, a characteristic which became a matter of heredity perhaps ten centuries ago, but the mode of its original acquisition is a mystery.

There is no really great scientist in biology at the present moment who teaches the hereditary transmission of acquired characteristics. Modifications of the organism that become matter for heredity have existed for many generations and we cannot tell just how they began. There is no doubt that there is some hereditary influence, for insanity in the same family is likely to keep recurring in successive generations. More than this, affections of certain less important organs are evidently a common trait in certain family strains. There is no doubt that in some families stomach affections are the rule in successive generations. It is very hard to say, however, just when such defective organisation became a family trait. The tendency to nervous affections is undoubtedly a similar family affair. Certain affections have been hereditary traits for many generations. An excellent example of this is the so-called Huntingdon's chorea, which several generations of American doctors, of the name of Huntingdon, by following carefully the history of certain families on Long Island, succeeded in tracing through four generations.

The habits of life of a father or a grandfather may so weaken the physical constitution of his descendants as to make them less capable of resisting infections in the physical order, or in the moral order of withstanding trials and temptations, and the allurement to abuse of nervous excitement to which they may be subjected. That some acquired pathological condition, however, as stomach trouble, or heart {123} trouble, or affection of the liver or of the brain, should be directly transmitted, is quite as nonsensical as that the loss of an arm should be a subject for hereditary transmission. On investigation it will be found that the pathological conditions of immediate ancestors are themselves only a manifestation of family traits that have existed for many generations. The possibility of inheritance must therefore always be borne in mind. We are utterly unable as yet to understand how such family traits are originally developed, since, in ordinary experience, at least, acquired characteristics are not the subject of inheritance or transmission, and consequently it becomes difficult to understand how they ever became impressed upon the family constitution.

Notwithstanding this general principle with regard to heredity, there are a number of striking observations which show that even unimportant peculiarities may occur from generation to generation, though it is not always easy to decide where the peculiarity originated. The well-known example of the occurrence of six toes has already been mentioned, and is an oft-quoted bit of evidence as regards hereditary transmission. An extra finger on the hand, or some portion of an extra finger, at least, comes in the same category. Not long since it was pointed out that harelip is another of these peculiarities that readily lends itself to hereditary transmission. Recently there was the report of a family into which there were born four girls with harelip and cleft palate, and three boys not showing any trace of these deformities.

Often when in such cases there is no definite history of harelip, it is found that in either one of the parents there is a very high arched palate and a thin upper lip, showing that the normal occlusion of the cleft which exists here during foetal development is not quite perfect, and this peculiarity may be traced for several generations back, with an occasional occurrence of harelip as an exaggerated example of the faulty tendency not to produce sufficient tissue in this neighbourhood for the proper closure of the embryonic cleft.

An even more striking manifestation of a physical anomaly, as a family trait, is the condition known as hemophilia. This {124} tendency to bleed easily, so that a slight scratch, or the pulling of a tooth, may give rise to fatal hemorrhage, occurs, as a rule, only in males, but is transmitted through the female line. It is in the mother's male relatives that the history of its previous occurrence is found, and the tendency usually can be traced through several generations, until it is lost in vague tradition. It is no wonder, with such examples before them as six-toedness, harelip, and hemophilia, that physicians have been ready to accept heredity of qualities in the moral order, traits of character and disposition, and pathological tendencies to crime or passion or indulgence.

One of the most frequently discussed conditions of supposed pathological inheritance of this order is dipsomania. Everyone has heard it said, "Poor fellow, how can he help it; his father was a drunkard before him." As we have already said, in such direct cases inheritance is absolutely unproven. An alcoholic father may transmit a very weak physical constitution to his children, and this may prove inadequate to enable them to withstand the emotional strain and worry of modern great city life, and, as a consequence, they may take to alcohol for consolation until the habit is formed, and then the craving for stimulants supplies the place of any hereditary influence that may be supposed to be needed.

Of course there are cases of the drink habit in which, after a number of generations of family history of alcoholism, an individual seems to have the craving for stimulants born in him. In such cases it is not unusual to find that the patient, for such he must be considered, is able to avoid indulgence in liquor entirely, except at certain times. Every physician of any large experience has had under his care dipsomaniacs who had no difficulty in keeping away from liquor for weeks, or even months, but who had regularly recurring periods, sometimes as far apart as every three months, when they had an irresistible craving for stimulants come over them. The regularity of the interval in these cases is often very remarkable. Here, of course, we may be in the presence of some as yet not well-understood periodical law of cell life, with consequent depression, and then the irresistible craving for stimulation. {125} As a rule, however, it would seem that in most of these cases suggestion has great influence. As we have said elsewhere, with regard to suicide, when a man has constantly before his mind's eye the fact that a father, perhaps a grandfather, or other members of the family, have committed suicide, he is likely to be much more easily led to the thought of this way of escaping hard conditions in life than are other individuals. The man who knows that the fact that his father indulged too freely in stimulants will be looked upon by many as an excuse for his deviations in this matter is likely to be more easily led to take an occasional drink at moments of depression, or for friendship's sake, though he realises that it so weakens his will power over himself that he is likely to take too much before he stops.

The passage in _Julius Caesar_ (Act. I. sc. 2) in which Cassius says:

"The fault, dear Brutus, is not in our stars, but in ourselves,"

illustrates one phase of the subject. There are, of course, many other things besides the drink habit, with regard to which men are prone to find excuses in heredity, and to consider that somehow their ancestral tendencies make them not quite responsible for actions commonly considered the result of malice or passion, rather than hereditary influence, and our great English poet, knowing men so well, has stated the truth forcibly.

In _King Lear_ there is an often quoted passage which properly stigmatises the opinion in this matter held by those who would find excuses for wrong-doing in hereditary qualities:

"This is the excellent foppery of the world, that, when we are sick in fortune,--often the surfeit of our own behaviour,--we make guilty of our disasters the sun, the moon, and the stars; as if we were villains by necessity; fools by heavenly compulsion; knaves, thieves, and treachers by spherical predominance; drunkards, liars, and adulterers by an enforced obedience of planetary influence; and all that we are evil in, by a divine thrusting on; an admirable evasion of whore-master man, to lay his goatish disposition to the charge of a star!"

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One phase of the question of hereditary tendencies to inebriety is extremely interesting from a physiological and sociological point of view. As the result of carefully gathered statistics, there seems to be no doubt now that when children are conceived while the parents, or either of them, is in a state of drunkenness, the offspring is very likely to be of low-grade physical constitution and often of very neurotic tendencies. In France, particularly in the case of a number of insane children and idiots, histories of this nature have been obtained in confirmation of this unfortunate factor as an element in degeneracy. In general it may be said that about one-third of the admissions to homes for children of low intelligence, as well as to insane asylums, are due to this cause.

There is in this, of course, an added motive for temperance, and it would seem that parents should be warned of the danger to which they are subjecting their offspring by excessive indulgence in alcohol, when it may be followed by such serious and lasting results to the beings on whom their love and affection will be expended in the future. This phase of alcoholic excess has never been taught as insistently as its importance would demand, perhaps because of the delicacy of the subjects which it involves; but it is too significant a factor in making or marring progress in the development of the race to allow any pusillanimous motives to prevent the spread of precious knowledge. [Footnote 3]

[Footnote 3: The present conditions that obtain with regard to the celebration of marriages are very prone to have a certain amount of intoxication as their result. Perhaps, then, it is a fortunate thing, as has often been said, that the first child is not born until some considerable time after it might normally be expected. It has been said more than once, however, that first children are a little more likely to have certain degenerative defects than are others, and a connection has been found between certain abuses of stimulants and incidental exhaustion to account for this. One of the most amusing things to Li Hung Chang, on his travels through our country, was the curious publicity we give to everything connected with marriage, while presumably our Christian ideas should rather counsel a veiling of the mysteries, religious and physical, connected with it. Certain it is that the present tendency towards farewell dinners at clubs, and other festivities of various kinds, are not at all likely to result in benefit to the presumably hoped-for offspring.]

The only real light that has been thrown on the puzzling details of heredity has come from work in the same field in which Mendel made his ground-breaking observations. {127} De Vries, the professor of botany at the University of Amsterdam, has succeeded in showing that new species of plants may be made to arise by careful attention to certain anomalous plants which occur from generation to generation. These plants breed true, that is, maintain their own peculiarities. To begin with, they are quite different from the parent plants, and the difference is perpetuated by inbreeding.

So far the problem of the origin of species has been supposed to depend upon the normal variation that is noticed in plants and animals. All living things differ from one another, even though they may belong to the same species, and differ sometimes in remarkable degrees. This continuous variation was supposed to account for the origin of new species when it became excessive. It has become well recognised now, however, that such differences gradually disappear in the course of the normal multiplication of plants and animals. The tendency is much more towards the disappearance than the maintenance of peculiarities.

There are certain discontinuous variations, however--sports, as they are called--in plants which differ very markedly in some quality from others, and these have the tendency to perpetuate themselves. Just why these sports occur is not known, nor how. They occur in a certain small percentage of all normal plants, but may die out, though it takes but little encouragement to succeed in helping them to maintain themselves. It is this that De Vries has done, and thus has succeeded in raising what would be called new species of plants.

This same thing would seem to occur in human beings. Some definite variation occurs as a consequence of a peculiar embryologic process. This becomes stamped upon the genital material and appears in the subsequent generations. It does not occur as a consequence of pathological changes nor of mere embryonic faults; it is almost as if it were something introduced from without. Once having found an entrance, however, it affects the germinal material and thus perpetuates itself.

With regard to plants, it has been suggested that the only explanation available for the occurrence of sports is that there is a purposeful introduction of them as the result of the laws of nature, and that it is thus that evolution is intentionally {128} brought about. This is, of course, a scientific reversion to teleology once more, but the question of teleological influences has been discussed more seriously in the last few years in biological circles than ever before. Unfortunately for the coincident evolution argument involved in human beings, the peculiarities introduced, which become the subject of inheritance, do not make for the development, but rather for the degeneracy, of the race. Even such peculiarities as six toes can scarcely be said to add any special feature of advantage to man in his struggle against his environment.

It is agreed by many of our best authorities in biology, zoology, and botany, by such men as Professor Wilson of Columbia University, Professor Thomas Hunt Morgan of Bryn Mawr, Professor Castle of Harvard University, Professor Bailly of Cornell University, Professor Michael Guyer of the University of Cincinnati, Professor Spillmann, who is the Agrostologtst of the United States Government, and Professor Bateson of the University of Cambridge, England, that these principles of heredity enunciated by Father Mendel will undoubtedly revolutionise the modern knowledge of the subject. In the meantime, however, all the old theories are in abeyance. Darwin's work and Weissmann's brilliant theories and observations must give way, while the application of these new laws is being worked out to their fullest extent. While the influence of heredity can not be denied, there is undoubtedly a tendency to overestimate the influence on the physical being of the power of hereditary transmission, and, on the other hand, to underestimate the influence of this same force as regards disposition and character. There is no doubt now that the physical basis influences the exercise of the will, and that consequently responsibility is not infrequently modified by the hampering influence of unfortunate physical qualities. This truth makes for that larger charity in the judgment of the actions of others which enables physicians to realise how much men are to be pitied, while its failure of recognition by the "unco guid" not only causes suffering, but in the end adds to the amount of evil.

JAMES J. WALSH.

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X

HYPNOTISM, SUGGESTION, AND CRIME

In recent years a quasi-unconscious state, induced by suggestion and called the hypnotic trance, has come to occupy a very important place in the popular mind. Hypnotism, as the general consideration of this state is known, has attracted not a little attention, as well from physicians as from those interested in psychology. The hypnotic (Greek, [Greek text], sleep) trance is a condition in which voluntary brain activity is almost completely in abeyance, though the mind is able passively to receive many impressions from the external world. There are very curious limitations in the effect of the hypnotic state upon the various senses. While visual sensations, and, as a rule also, impressions from the tactile sense, lose their significance, or are translated according to the will of the person active in producing the hypnotic state, or of some person present making suggestions, auditory sensations are quite normally perceived. The patient has all the appearance of being asleep, though motions, and even locomotion, are often possible, and are performed as if the patient were walking in sleep.

The hypnotic state is a partial sleep, then, of the motor side of the nervous system and of portions of the sensory nervous system. Certain of the higher intellectual powers, however, are entirely awake, and capable of being impressed through the hearing, and thus hypnotic suggestion has a place. For a time, under the influence of Charcot and his disciples, there was a very generally accepted opinion that the hypnotic trance was a pathological condition, somewhat allied to the cataleptic phase of major hysteria. It is well known that persons suffering from severe attacks of hysteria {130} may, while apparently unconscious, yet receive suggestions through the hearing. On the other hand, the production of cataleptic and other strained attitudes, in the maintenance of which fatigue seems to play no part, is possible by means of hypnotic suggestion in susceptible individuals.

Further investigation, however, seems to have shown that the hypnotic state is rather to be considered as a quasi-physiological condition, somewhat related to sleep, all the mystery of which is not as yet understood. This is not surprising when we realise that such a normal and absolutely physiological condition as healthy sleep is yet without a satisfactory explanation on the part of physiologists. Hypnotism is recognised now as having a certain limited power for good, though the benefit derived from it is apt to be temporary, and the operator loses his power after a time,--not so much failing to produce the hypnotic condition, as failing to have his suggestions favourably accepted by the subject While the Nancy school of hypnotism insisted that most people were susceptible to the hypnotic trance, it is now generally considered that something less than 40 per centum of ordinary individuals can be brought under its influence.

Much has been said of the dangers of hypnotism. There seems no doubt that very nervous persons are likely to be hurt by repeated recourse to the hypnotic condition. After a time they are likely to live most of their lives in a half-dreamy condition, in which initiative and spontaneous activity becomes more difficult than before. Where persons have been hypnotised by means of the flash of a bright object, or by some other special means, it sometimes happens that accidentally some similar object may send them into hypnotic trance. After a time, too, auto-hypnotism becomes possible, and much of the individual's waking time is occupied with efforts to keep himself from going into the hypnotic trance. These are, however, very extreme cases, likely to occur only in those who are not of strong mentality in the beginning. Unfortunately these are the individuals who are most likely to be made the subjects of repeated and prolonged hypnotic experimentation on the part of unscrupulous charlatans.