HEREDITY: IS ACQUIRED CHARACTER OR CONDITION TRANSMITTIBLE?
It has been well said by Herbert Spencer, and more recently by Professor Osborn, the able biologist of Columbia College, that the question involved in the discussion of heredity is not a temporary issue and that its solution will affect all future thought. Whether or not acquired character is transmitted to children is the most important question that confronts the human race; for it is upon the character of the race that depends and will depend the condition of the race.
No school of scientists questions the fact of heredity; but there is a warm and greatly misunderstood contest over the exact method used by nature in the transmission. Now so far as the general public is concerned, so far as the sociological features of the case go, so far as personal conduct is involved, it does not matter a straw's weight whether the theory of heredity held by Lamarck and Darwin, or the one advanced recently by Weismann, be correct.
It matters not whether your drunkenness, for example, is transmitted to your child directly as plain drunkenness, or whether it descends to him as a merely weakened and undermined "germ plasm" which "will tend to inebriety, insanity, imbecility" or what not. It matters not a farthing's worth, from the point of view of the laity, whether the transmission is direct, via "pangenesis," or whether it is indirect, via a weakened and vitiated "germ plasm" as per Weismann, or whether the exact method and process may not still lie in the unsolved problems of the laboratory. Whichever or whatever the exact process may be (which interests the scientist only), the facts and results are before us and concern each of us more vitally than does the question of what we shall eat or what we shall drink or wherewithal we shall be clothed. It is all the more unfortunate, therefore, that even an untested scientific theory cannot be advanced without the ignorant, the half-educated and the vicious taking it in some distorted form as a basis of action. Indeed it would seem to be wise, if one is about to make a scientific suggestion of importance, to take the precaution to say in advance that you don't mean it—for the benefit of that large class of intellectual batrachians who hop to the conclusion that you said something totally different from your intent.
Because a surgeon might say to you that he knows a boy who carries a bullet about in his brain and that the youth appears to be no worse for it in either body or mind, it would not be safe to imply that he proposes to teach you that it would be a particularly judicious thing for you to attempt to convert your skull into a cartridge box.
Because Weismann asserts and attempts to prove that nature's method of hereditary transmission precludes (for example) the possibility of producing a race of short-tailed cats from Tom and Tabby from whose caudal appendages a few inches have been artificially subtracted, some of his followers exclaim in glee: "It does not make the least difference in the world what we do or refrain from doing in one lifetime. Our children do not receive the results; we cannot transmit to them our vices or our virtues. We cannot taint their blood by our ill conduct nor purify it by our clean living. The 'germ plasm' from which they came is and has been immortal; we are simply its transmitters—not its creators. Our children were created and their characters and natures determined centuries before we were bom. We are in no sense responsible for what they may be; germ plasm is eternal; we are exempt from responsibility to posterity. Long live Weismann!"
Now this is about the sort of thing that is springing up on every side as a result of the new discussion as to how we are to account for the facts of heredity. One sometimes hears, also, from these half-informed jubilators that "Weismann does not believe in heredity; that old theory is quite exploded." The fact is that Weismann is particularly strong in his belief in heredity—so strong as to give almost no weight to any possible process of intervention in its original workings. He simply holds that the transmission of "acquired character" is not proven, and he doubts the fact of these "acquired" transmissions. In his illustrations he deals chiefly (when in the higher animals) with mutilations, and in the human race shows that the most proficient linguist does not produce children who can read without being taught!
Of course there are many and varied points in his theory of heredity with which only the biologist is capable of dealing. But as I intimated at first, the Lamarck-Darwin-Weismann controversy, so far as the sociological aspect of the question is involved, does not touch us. It belongs to the laboratory—to the how and not to the fact of transmission. But since the opposite impression has taken root in even some thoughtful minds, it is well to meet it in a direct and easily grasped form. There is a simple and direct method; I undertook it. I went to a number of well-known biologists and physicians and asked these questions;—
1. Are there any diseases known to you, which you are absolutely certain are contracted by individuals whose ancestors did not have them, which diseases you can trace as to time and place of contraction, and which are of a nature to produce physical and mental changes that are recognizable in the child as due to the parent's condition?
2. Have you ever had such cases under your own care?
3. Have you a record of cases where the children of your patients received the effects of the disease of the parent in a manner that would show that "acquired character or condition" is transmittible?
4. Is this true in a kind of disorder which would produce in the child a change of structure or condition so profound as to change its character and run it in a channel distinctly the result of the "acquirement" of the parent?
I thought it best to go to specialists in brain and nerve disorders and to those who had had large hospital or asylum experiences. One of these, Dr. Henry Smith Williams, ex-medical superintendent of Randall's Island, where the city of New York sends its imbecile and epileptic children, and where many hundreds of these came under his care, replied that there could be no doubt of the fact that such "acquired" characters or conditions are transmitted. One case which he gave me, however, from his private practice will illustrate the point most clearly. B., a healthy man with no hereditary taint of the kind, acquired syphilis at a given time and in a known way. Before this time he was the father of one daughter. Several years later another daughter was born to him. The first girl is and has always been absolutely free from any and all taint. The other one has all the inherited marks of her father's "acquired character" and condition, which even went the length in her of producing the recognized change in the form of the teeth due to this disease. Now for all practical purposes it does not matter in the faintest degree whether that transmission was in accordance with pangenesis or by means of a vitiated environment of the "germ plasm." The fact is the appalling thing for the reader to face. And I give this case only because it was one of a vast number of similar ones which came to me in reply to my questions addressed to different practitioners and specialists.
Among other places, I went to the head of a maternity hospital. This is what I got there: "If Weismann or any of his followers doubts for one second the distinct, absolute, unmistakable transmission of acquired disease of a kind to modify 'character' both mental and physical—if they doubt its results on humanity—they have never given even a slight study to the hospital side of life.
"I can give you hundreds of cases where there is no escape from the proof that the children are born with the taint of an 'acquired character' from which they cannot free themselves. Sometimes it is shown in one form, sometimes in another, but it is as unmistakable as the color of the eyes or the number of the toes. To deny it is to deny all experience. I am not a biologist and I do not undertake to explain how it is done, but I will undertake to prove that it is done to the satisfaction of the most sceptical. Come in this ward. There is a child whose parents were robust, healthy, strong country folk until"—and then followed the history of the parents who had "acquired" the "character" which they transmitted—which had made the mental, moral and physical cripple in the ward before me. "Now here is what they transmitted. Do you fancy that if that half idiot should ever have children they will be 'whole'? No argument but vision is needed here. That child's condition is the result of acquired character. Its children and its children's children will carry the acquirement—for we are not wise enough yet to eliminate even such as that from among active propagators of the race! If it were possible (which, thank Heaven, is not likely) that the other parent of this half imbecile's children would be of a sane and lofty type there might be a modification upward again in the progeny, but even then we would not soon lose the direct, undeniable, patent 'acquirement' which you see here."
It was the same story from each and every practitioner. The hospital and asylum experts, the specialists in diseases of mind or body which were due to direct acquirement (such as drunkenness, syphilis and acquired epilepsy), were particularly strong in their contempt for even the theory that acquired character and condition are not transmittible. One laughingly said: "I'll grant that if I cut off a man's leg or a few of his fingers, his children will not be likely to be deformed because of that operation. This is not a permeating constitutional condition, it is a mere local mutilation. But if I were to take out a part of his brain so as to produce ["acquired">[ epilepsy upon him I believe his children will be affected, and if he is a bad syphilitic [acquired] I know his children will be. Mind you, I don't say exactly what they will have, and they may not all have the same thing, but I do say that their 'germ plasm' or whatever they come from, will carry the results of the acquired condition and character." *
*"Brown-Sequard observed that injury to the central or
peripheral nervous system (spinal cord, oblongata, peduncle,
corpora quadrigem-ina, sciatic nerve) of guinea pigs
produced epilepsy, and this condition even became
hereditary. Westphal made guinea pigs epileptic by repeated
blows on the skull, and this condition also became
hereditary."—** Manual of Human Physiology," by L. Landou,
translated with additions by W. Sterling. 1885.
Dr. L. Putzell, in his "Treatise on the Common Forms of
Functional Nervous Diseases," 1880, after describing the
methods by which Brown-Sequard produced epilepsy
traumatically in guinea pigs, says: "Brown Sequard also
made the curious observation that the young of guinea pigs
who had been made epileptic in this manner, may develop the
disease spontaneously. These experiments have been verified
by Schiff, Westphal and numerous other observers."
So I beg of you to remember that while the fact and law of heredity is as certain as death itself, its course of action, its variability of operation, is as the March winds. To say that the constitutions of your children will be de* termined in great part by the condition of your body and mind is but to utter a truism; but to say exactly how—in what given channel this effect will flow—is not, in the present state of biological knowledge, possible.
For the sake of illustration it is usually the part of wisdom to give the most probable trend of a given disorder; but to assert dogmatically that the son of a lunatic will be insane or that the daughter of a woman of the street will live as her mother did, is quite as unsafe as to say that a fall from a fourth-story window on to an iron door would be certain death. You must not forget that you may, if you want to take the chances, drop an infant out of a fourth-story window on to an iron door with no bad results to the infant (door not heard from), for I have known that to happen; you may sleep with a bad case of small-pox and not take it—as I once did; you may shoot a ball into a boy's head, taking in with it several pieces of bone, you may extract the bone and leave the ball there and the boy appear to be as good as new afterward; you may live all your life long with a roue and your children not be inmates of hospital, lunatic asylum or prison. All these things have been done, but it is not the part of wisdom to infer that for this reason either one of them would be a safe or desirable course of action; for in this world it behooves us to deal—when we are attempting to study nature—with the law of probability. The accidents, the exceptions, will take care of themselves.
Notwithstanding this fact it will not be exactly fair to me for you to report that I say that every single one of Jane Smith's children will have fits and fall in the fire before they are twenty-one because she or their father is an epileptic. Perhaps one or two of those children may die in infancy, instead, or go insane—or to Congress; one may have hydrocephalus, and another be a moral idiot and astonish the natives because "His parents were such upright people." One may simply have a generally weak constitution—and another may win the American cup for wrestling; but the chances are that confirmed epilepsy (or what not) of the parent is going to "tell" in one form or another in the children. What I say of epilepsy is equally true of syphilis. This latter is so true that it can be readily told by the teeth of the children of a seriously infected case. That will strike the average "unprofessional" reader as impossible, yet it is well known to biologists, medical men and many dentists, so that a great many wholly innocent people who sit in a dentist's chair reveal more private family history than could be drawn from them with stronger instruments than mere forceps.
I have been asked to write this paper because at the present time there is a tendency to discredit some of the well-known and easily proven facts of heredity, as a result of certain statements supposed to have been made by the recent school of biologists headed by Weismann. But in the hands of the laity much that Weismann did say is misunderstood and misstated and much that he never said is inferred. To professional biologists the loose inferences from Weismann's suggestions and speculations are absurd, and to experienced medical men and experts in the lines of practice indicated above, the arguments are beneath discussion. It is in this particular line of practice that proof is easy and abundant, where the "acquired" nature of the modified "character" is readily traced and the transmission (or heredity) susceptible of proof beyond controversy.
It is for this reason that the illustrations are all taken from this field of investigation. If they were taken from consumption, tuberculosis or any of the various ordinary "transmittible" disorders, the cheerful opponent would assert (and no one could disprove if he held to the "germ plasm" theory back far enough) that the "tendency" had been inherent in the plasm since the days of "Adam"—that it was not an "acquired" character or condition which was transmitted. But with artificially produced epilepsy (either by accident or purposely as in the cases of Brown-Sequard's guinea pigs) or in the other so frequent and so frightful disorder mentioned above, it is a simple matter to trace the "acquirement" as well as the transmission. But when a new light arises in the literary or scientific world there are always many persons ready to spring forth with the declaration that they agree with the new point of view without first taking the precaution to ascertain what the recent theory really is. "Oh, I agree with him, the old theory is quite dead," greets the ear, and the placid pupils of the rising light so warp and distort the real opinion of the master as to make of him an absurdity. This has been markedly true of Weismann and his theory of heredity.
In ordinary cases of scientific discussion the misconceptions of the laity would soon adjust themselves and little or no harm would be done meantime; but in such a problem as the present far more is involved than appears upon the surface. The ethical and moral results—not to mention the physical—of a reckless mistranslation or misconception of a scientific theory of this nature cannot be readily estimated, nor can it be confined to one generation. It is pathetic to realize that many fairly well-educated and well-meaning people, who would protect with their lives the children they give to the world and shield them against all possible physical, moral or mental distortion, mutilation or deformity, will stamp upon those children far worse mutilations and distortions (and even physical disorders) through and because of a half-understood version of u the new theory of heredity. Therefore I repeat that so far as the public is concerned, so far as the sociological features of the problem of heredity are involved, so far as the new theory relates to conduct and to physical and mental condition and their transmission, this controversy belongs to the laboratory—to the how and not to the fact of hereditary transmission, as I trust the above illustrations (which might be multiplied a thousand times) will serve to show.