What Is LAW OF HEREDITY.
I once heard of a man who on his death-bed made a singular will. He had no houses or lands to bequeath his children, but he had observed that they had inherited much from him, and so he made a formal bequest to them of that which they already possessed.
He wrote: “I bequeath to my son John my big bony frame and the slouching gait I acquired by carelessness, also my inherited tendency to consumption. To my daughter Mary I bequeath my sallow complexion and torpid liver, which are the result of my gross living; also my melancholy disposition and tendency to look on the dark side of life. To my son Samuel I give my love for alcoholic liquors and my irritable disposition; to my daughter Jane my coarseness of thought and my unwillingness to be restrained in my desires, and also my tendency to commit suicide.”
“A very strange will,” said everybody, and yet it was a will that was probated long before the testator’s death. That it gave perfect satisfaction I will not assert, but it was never contested and paid no fees to lawyers.
Just such wills are being made daily by the lives and conduct of young people, though they are not put into writing. Some time in the future, however, they will be written into “living epistles, known and read of all men.”
Other wills are being made daily that through sober, virtuous, youthful lives will bequeath to posterity dowers of health, strength, purity and power.
This being true, it seems only a part of prudent foresight to study in youth the law that governs the transmission of personal characteristics to the future “denizens of life’s great city.” This law is known as Heredity, and its first written record is in the first chapter of Genesis, where it is written that “Every plant and animal shall bring forth after its kind.” We are so accustomed to seeing the results of this law that we give it little or no thought. We see that grass springs up each year on our lawns and meadows. We know that if we put the seeds of a certain flower in the ground, that kind of flower will always spring up, never another kind. The farmer is not anxious, after he sows wheat, for fear that the crop will be rye or barley. We expect that the young of cats will be kittens, of geese will be goslings, of men will be human children, and we are never disappointed. The law holds good under all circumstances.
We see, too, that there are certain race characteristics that maintain. The Mongolian race has peculiar high cheek-bones, sallow complexions and eyes set in bias, and we recognize the Japanese or Chinese at once, even though dressed in the garb of our country. So, too, we recognize the African or the Caucasian by certain marked characteristics. This transmission of racial traits we call race heredity.
Then each race has its own traits, physical or mental, which we recognize as national, and so speak of them. We always mention thrift as an attribute of the Teutonic nations; the Irishman we characterize as witty and pugnacious; the Frenchman as polite; the American as progressive.
Each individual has not only his human inheritance, his race inheritance and his national characteristics, but he has also an endowment of family traits.
But we are not made up of odds and ends of ancestral belongings alone. We have in ourselves something that is original, that makes us different from each other, and from all others. I have sometimes thought that we are somewhat like patchwork quilts, the parti-colored blocks being set together by some solid-colored material; or, better still, we are like “hit and miss” rag carpets, with a warp of our own individuality, filled in with a woof made of qualities and capacities of all those who have preceded us. You know, in making “hit and miss” rag carpets we take little strips and bits of various materials and all colors, and sew them together without regard to order or arrangement, and these long strips are woven back and forth in the warp until the carpet is woven, showing no set pattern, but a mingling of tints and shades that is sometimes crude and unsightly, sometimes soft and artistic.
I used, in childhood, to find great delight in seeking among the blended colors in the carpet for scraps of clothing which I recognized as having belonged to father or mother, or perhaps even to grandparents. Even now, in my maturer years, I am interested in finding in myself the physical, mental or moral characteristics of those same ancestors; and you, no doubt, can do the same, while some of your traits seem to be yours entirely, constituting individual variations upon ancestral inheritances.
Nature has been doing for centuries, unheeded, what the photographer of to-day thinks is a modern discovery, that is, making composite photographs of us all.
Through this law of inheritance have arisen the intellectual, the moral or the criminal types of humanity, and the process is continuing; the types are becoming more and more marked, or modifying influences are being brought in to change the type.
These influences are also the result of law, even though we may not be able to trace them to their cause. Knowing this, however, we begin to see that heredity is not fatality; that the power to modify the endowments of future generations is ours. To know how to employ it, we should study the law as far as we have opportunity.
This subject is a large one, and no doubt you will some day want to give it a thorough investigation. Just now, however, you will have to accept my statements. I will not make them technical, but strictly practical to you as a young woman desiring that knowledge which shall best fit you for the responsibilities of future life.
A superficial study is rather discouraging. We see with what certainty evil characteristics are transmitted, and we feel that the law is a cruel one; but if we have patience we shall find that, like all laws of God, its purpose is for the benefit of the race. Before we begin to take comfort from the law let us first learn its warnings, one of which is that all weakening of the individual, either in bodily strength, in intellectual power or moral fiber, tends to produce a like weakness in posterity. This is why I say to you that the young people of the present have in their hands the welfare of the future. Their habits to-day are moulding the possibilities of the race. Young women may feel that their individual violation of the laws of health is of no importance, but when they realize that the girls of to-day are the mothers of the future, and that the physical strength or weakness of each individual girl affects the average health of the nation, not only now, but it may be through her posterity for centuries, we can see that each girl’s health is a matter of national and of racial importance.
But it is not alone in the physical organization that we can trace the law of heredity in the transmission of undesirable qualities. We find that evil traits and tendencies of mind or morals are transmissible. Galton finds that a bad temper is quite sure to be passed on from one generation to the next, and any peculiarity of disposition in either parents is quite likely to become an inheritance of the child. This fact makes our little faults seem of vastly more importance than otherwise. We can endure them in ourselves, but they strike us very unpleasantly when we are obliged to see them manifested in our children. As the poet says:
It may not strike us very unpleasantly when we speak disrespectfully to our parents, but when our own children show us lack of courtesy and cheerful obedience it cuts deeply, and all the more deeply if we see in their conduct but a repetition of our own.
Of course, if these minor faults are transmissible, we will not be surprised that graver moral defects are passed on. The grandson of a thief began to steal at three years of age, and at fourteen was an expert pickpocket. The police records show the same family names recurring year after year.
These cases are so grave as to attract attention, while we overlook the fact that the smaller immoralities are as apt to be transmitted, and perhaps with increased power. I should be afraid that slight lack of strict integrity in the father might appear as actual crime in the son.
I would not omit to mention also the law of Atavism, in this discussion of heredity. This is that expression of the law in the omission of one generation in the transmission of a quality. We sometimes see the peculiarities or defects of a man or woman not manifested in their children, but reappearing in their grandchildren.
Not long ago I was in a family where both parents and all the children had dark hair but one, and she had long, bright auburn ringlets. I asked, “Where did you get your hair?”
“From my red-headed grandmother,” she answered, with a laugh, indicating that the matter had been so often discussed in her hearing that she understood it quite fully.
To cover the whole scope of the law of heredity would take more time than we have to spare. You can follow out the line of thought, and make practical application of the facts and principles here laid down.