I shall now ask you to proceed with me to a consideration of the various phases of Pre-Natal Influences coming under the above name three general classes, and the principal factors involved therein.
Heredity in General.
By "heredity" is meant "the tendency which there is in each animal or plant, in all essential characters, to resemble its parents"; or "the hereditary transmission of physical or psychical characteristics of parents to their offspring."
There is a great disagreement among the authorities as to how far the principle of heredity really extends, and the real causes of heredity are in dispute. In the present consideration we shall, of course, pass over the technical phases of the subject, and shall touch only upon the general features and principles involved.
Shute, in his work entitled "Organic Evolution," says: "That an offspring always inherits from its parents many of their characteristics is well known; that it always varies, more or less, from them, is also equally well known. Heredity and variation are twin forces that play upon every creature, holding it rigidly true to the parental type or compelling more or less divergence therefrom, according to the strength of the one or other power; so that every creature is the resultant of the activities of these two great parallel forces. Variation is co-extensive with heredity, and every living creature gives evidence of the existence of variations.
"Mental heredity can be illustrated by studying the genealogies of such persons as Aristotle, Goethe, Darwin, Coleridge, Milton, etc. Probably the Bach family, of Germany, supply one of the best illustrations of the inheritance of intellectual character that we know of. The record of this family begins in 1550, lasting through eight generations to 1800. For about two centuries it gave to the world musicians and singers of high rank. The founder was Weit Bach, a baker of Presburg, who sought recreation from his routine work in song and music. For nearly two hundred years his descendants, who were very numerous in Franconia, Thuringia, and Saxony, retained a musical talent, being all church singers and organists. When the members of the family had become very numerous and widely separated from one another, they decided to meet at a stated place once a year. Often more than a hundred persons—men, women, and children—bearing the name of Bach were thus brought together. This family reunion continued until nearly the middle of the eighteenth century. In this family of musicians, twenty-nine became eminent.
"Inheritance of moral character is well known. Heredity, in its relation to crime and pauperism, has been thoroughly investigated by Mr. Dugdale in his most instructive little work entitled "The Jukes." In this work the descendants of one vicious and neglected girl are traced through a large number of generations. It reveals that a large proportion of the descendants of this woman became licentious, for, in the course of six generations, fifty-two percent of the children were illegitimate. It shows also that there were seven times more paupers among the women than among the average women of the state, and nine times more paupers among the male descendants than among the average men of the state. The inheritance of physical peculiarities is so obvious as to need no illustration. Among the ancients the Romans stereotyped its truth by the use of such expressions as 'the labiones' or thick-lipped; 'the nasones,' or big-nosed; 'the capitones,' or big-headed, and 'the buccones,' or swollen-cheeked, etc. In more recent times we read of the Austrian lip and the Bourbon nose."
But in all considerations of the subject of heredity, one must always remember that the inheritance of physical, mental, and moral characteristics is not alone from the immediate parents, but rather from many ancestors further removed in order and time. Back of each person there is a long line of paternal and maternal ancestors, extending back to the beginning of the race. And in that line there are influences for good and evil, awaiting favorable environment for awakening into new life unless restrained by the will of the individual.
As Shute says: "There will come a time when the fertilized ovum will have a highly complex nucleus composed of many different ancestral groups of hereditary units. One often hears the expression that a child is a chip of the old block; but this is only a very partial truth, for the child is pre-eminently a composite chip of many old blocks." And Luther Burbank has well said: "Heredity means much; but what is heredity? Not some hideous ancestral spectre, forever crossing the path of a human being. Heredity is simply the sum of all the environments of all past generations on the responsive ever-moving life-forces."