Lesson XX SEX AND HEREDITY

THE ORIGIN OF SEX

That part of human life and living that is associated with the functions of sex and reproduction is at once the cause of the world's greatest misery and the world's greatest happiness. It is the subject of the greatest popular ignorance and superstition, and at the same time the field of the most wonderful of all scientific knowledge.

For the origin of sex we must look back into the remote ages of creation in the early stages of organic evolution.

Fundamental function of the cell

The first essential property of matter that makes life possible is the power of nutrition, which means the ability of the living cell to transform other chemical substances into its own protoplasm or living substances.

But this world would have remained a barren mass of igneous rock if nutrition had been the only function with which the earlier forms of life were endowed. Not only must the living cell be enabled to grow by absorbing other substances, but it must reproduce itself, or multiply the number of living individuals.

First form of reproduction

The first method by which this was accomplished was undoubtedly one of simple division; that is, the living cell grew by absorbing other substances and when sufficient size had been attained, divided, forming two daughter-cells. This division process of reproduction is the form by which all bacteria (so-called dis-ease germs) and many other lower forms of life increase their numbers.

Second form of reproduction

Strength in fusion of cells

This process of reproduction, by simple division, was early supplemented by another process of reproduction in which two living cells first fused or combined and then divided to form two or more daughter-cells. This form of reproduction seems to have added stimulus or vitality to the organisms. The supposed reason for this is that the isolated cell was inclined to weaken or lose its chemical balance or tone. The exact nature of this deterioration is not very clearly understood, but in a higher form of life it is well illustrated by the tendency of certain plants to "run out" when grown continually in the same soil, or of animals to become weakened when inbred. At least, all scientists concede that with the process of fusion or the combining of two cells there is added a stimulating and invigorating force which enables life to combat more successfully the unfavorable elements of its environment, and to change or evolve into higher forms.

Sexual reproduction in plants

Throughout the range of plant and animal life this process of cell union, or sexual reproduction, has grown and become elaborated into most varied and wonderful forms. Large volumes could be written describing the many wonderful adaptations of plant and animal life, the purpose of which is to secure sexual reproduction. All those who have studied botany are familiar with the many ways in which the seeds of plants are fertilized by pollen. For instance, certain species of orchids have a receptacle in the blossom, shaped like a teapot, which is filled with a fluid resembling water. This little teapot has an entrance and an exit. Near the entrance is sweet-scented nectar which attracts the bee. Fertilization of orchids As the bee passes through this gateway he is tripped up on a little trap-door arrangement and precipitated into the fluid. His wings having become wet, he is obliged to crawl out through the exit.

The wonderful process of flower fertilization

The object of this elaborate device is as follows: In the entrance passageway is located the stigma (female organ), while in the exit passageway the male or pollen-bearing organ of the orchid is found. The bee visits several of these flowers consecutively, and, as he makes his exit from each flower, he bears away on his body a portion of the pollen, which is transferred to the stigma of the next flower visited; while the bee, being forced to go through a "plunge bath" before visiting another flower, acquires a fresh load of pollen in each case. This scheme is a certain means of securing fertilization or sexual reproduction, and positively prevents inbreeding (the fertilization of a flower by its own pollen). This is merely one of the wonderful adaptations of nature in the solution of the sex problem.

Reproduction among fishes

In the animal kingdom the methods of sexual reproduction are also varied and wonderful. In many of the lower forms of animals, such as the various sea-creatures, the methods of reproduction may be those of division, as first mentioned, or a method combining division with true sexual reproduction. In the case of fishes, the eggs of the female are deposited in the bottom of a stream and are later fertilized by the sperm-cells of the male fishes. This involves a tremendous waste of reproductive cells, scarcely less extravagant than the waste of pollen in plants, such as is seen in a corn-field when Nature's wasteful methodsthe ground becomes yellow, during the tasseling season, with the myriads of pollen grains that failed to secure lodgment upon the silks of the young ears of corn.

Reproduction in higher forms of life

In the types of animals that are of higher form than fishes, that is, reptiles, birds, and mammals, the fertilization of the germ-cell (egg) takes place within the body of the female. In the case of the latter group—mammals—the true egg is hatched within the body of the female, and the offspring, or embryo as it is known to scientists, grows there for a considerable period before birth.

A RATIONAL VIEW OF SEXUAL HEALTH

The anatomy and the physiology of reproduction will not be considered in detail in this work, as this would require a very lengthy and technical treatise. The remainder of the lesson will be devoted to the relation of the reproductive functions to general health and happiness.

Development of reproductive instincts

In the process of evolution this function of reproduction was vitally essential to the life of the race. As a result there developed in all animal life strong sexual or reproductive instincts. As is plainly evident, all animals, including man, with such instincts most strongly developed would be the most successful in producing young, and through these offsprings the race or species would inherit like reproductive desires.

Kinship of the sexual, paternal and social instinct

In the case of man and the higher form of animals, this general instinct, the purpose of which was to produce offspring, became diversified in to many instincts. Not only does the reproductive instinct in this broad sense include what is commonly known as sexual passion in man, but it may very truly be said to be the essence of sexual love and parental love. Broad-minded scientists are even inclined to believe that the so-called social instinct or love for our fellowmen is but a distant reflection or shadow, as it were, of the original or natural instinct to produce offspring.

There has arisen among civilized man a tendency to separate and class as two distinct things the strictly physical element of sexual desire, and the associate emotion of intellectual love between the sexes. As a matter of fact there is no distinct line of demarcation.

Overindulgence, degenerating and destructive

That the former instinct has grown into disrepute and has come to be considered a forbidden topic in polite society, is due to the fact that sexual passion, like all other human acts which may be a source of gratification, can degenerate by overindulgence into a destructive and demoralizing vice. This is equally true of other forms of appetite, but the reason that the instinct of sex, when degenerated, becomes such a tremendous source of destruction and death is because of the important part played in the game of life by the reproductive function.

Relation of sexual functions to the nervous system

The functions of reproduction are, in both sexes, very intimately and closely associated with the nervous or vital mechanism of the entire body. For this reason, when the sexual function are perverted or abused the result is serious injury to the general nerve tone or vital force of the system. Likewise the contrary proposition is true; therefore, when for any reason, the general nervous tone or vital force of the body is deranged, the associated result is frequently abnormal passion or weakened sexual functions.

Necessity for popular knowledge concerning sex

A great deal of literature has been written and circulated throughout the country by well-intentioned individuals purporting to give popular knowledge regarding the subject of sex. But such literature has greatly exaggerated the evils and the dangers connected with sexual health. Outside of specific germ dis-eases transmitted through the sexual organs, and which, while serious, have been painted much darker than the facts justify, there is little excuse for all this horror and scare about sexual weakness and perversion.

Relation of nutrition to sexual health

Sexual health, like mental or muscular health, is a matter of common sense and right living. Proper feeding, proper oxidation, proper circulation (exercise), perfect elimination of waste-products, and a suitable distribution of both mental and physical work will result in perfect nutrition. This means normal, wholesome body-fluids and body-cells. With these things gained, the sexual organs and sex-function will have a fair opportunity for normal existence, and the matter of sexual health, and the consequent happiness which accompanies it, is then simply a matter of temperance, common decency, and self-control.

EMBRYOLOGICAL GROWTH—PRENATAL CULTURE

Superstition concerning prenatal culture

Upon the growth of the human embryo, or so-called prenatal culture, there exists a great deal of popular superstition, which is utterly groundless from the standpoint of accurate science. The views that have been promulgated regarding prenatal culture are for the main part harmless, and, for that matter, may be productive of good.

Theory of prenatal culturists

The idea of the prenatal culturist is that the mental as well as the physical growth and development of the unborn child can be controlled by the mother. The only ground for this belief is as follows: The child is nourished from the blood or nutritive fluid of the mother, with the result that the growth and the development of the child may be very readily influenced by the nutrition of the mother.

Influence of fright, anger, etc.

The mental condition of the mother has an influence on the growth of the child, but it is indirect. All organs and functions of the human body are controlled by the nervous system, and if the nervous impulse be deranged or weakened it may result in a serious impairment of nutrition. For this reason fright, anger, and other strong passions may result in lasting injury to the unborn child, but this injury is at most a matter of stunting or malnutrition, and cannot result in the voluntary mental life of the mother being transmitted to the child.

Mother's nutrition the only factor in influencing her child

As evidence of these assertions, I would call the reader's attention to the fact that there is no nervous connection whatever between the embryo and the mother, but after the fertilization of the germ-cell, the only way in which the mother can influence the growth of the child is by the nutrition which her blood supplies to the growing tissue of the embryo.

Birthmarks

As further proof of these statements, I will cite the investigations of Darwin in regard to the popular superstition of birthmarks. At the instance of Mr. Darwin, some seven or eight hundred women of a London hospital were very carefully questioned before the birth of the child, as to any incidents which had happened that, according to popular notions, might result in birthmarks or deformities. In no instance was any incident given which resulted in the expected deformity; but the most interesting feature of the investigation was that several women whose children were born with birthmarks recalled, upon seeing the deformity, some incident which seemed to give a possible explanation, thus showing to the mind of anyone familiar with psychology that the true explanation of all so-called remarkable incidents of birthmarks and of prenatal influence is merely one of superstition or self-deception.

HEREDITY

How often we hear someone remark upon the wonders of heredity. People are astonished because John should look like John's father. As a matter of fact, the astonishment should come the other way. The child is but a continuation of the life of the parents. The cells from which the child develops have within them the power to grow and to produce individuals like the parents. This is wonderful, but it is only another form of the wonder of a willow twig growing into a willow tree when placed in moist earth.

Why the child is not identical with parents

To the scientist, then, the wonder comes, not in the fact that the child resembles the parent, but in the fact that the child is not identical with the parent. Part of the explanation of this lack of identity, or, as it is known to science, variation, is due to the fact of sexual reproduction; that is, to the fact that the child has two parents instead of one.

Microscopic study of reproductive cells

The physiological process which takes place in the union of two reproductive cells is truly most wonderful. Of late years this has been studied under powerful microscopes and has resulted in some very wonderful revelations of the mysteries of Nature.

Chromosoms in different species

The nucleus (center of growth) of the parent cells contains little thread-like structures known as chromosoms. These chromosoms are considered to be the physical basis of heredity. In each species of animal there is a definite and a different number.

Action of the chromosom

When the sperm-cell unites with the female or germ-cell, these thread-like chromosoms pair off and unite each chromosom with the corresponding structure from the other cell. The combined structures then divide, and half of each chromosom is cast out of the cell-nucleus, and plays no part in the life of the future being; the other half is retained and divides as each new cell is formed.

Thus we see that every part of the new individual is the result of the fusion or combination of the two parents. This explains the variation of inheritance, and through this source must be traced all traits of heredity. After the original fusion of these microscopic physical elements of heredity, the future development of the individual is wholly a matter of environment and nutrition.

WHAT HEREDITY IS

General characteristics due to heredity

What heredity is and what it is not will now be considered in a practical way. It is clearly a matter of heredity that a man is born a man and not a monkey. Likewise, it is clearly a matter of heredity that distinguishes the various races of men. We could go farther and trace out and describe many of the physical distinctions which mark families, and even individuals, such as general size of frame, form of countenance, color of hair and eyes, etc.

Characteristics not attributed to heredity

Among mental traits we can safely ascribe to heredity only general distinctions. Intellectual parents are more likely to give birth to intellectual children than are parents whose natural mental faculties are less developed. There is also no doubt that certain natural characteristics of mind, such as quick temper, musical ability, etc., may be inherited. The belief, however, in the inheritance of many less distinct features, both physical and mental, is not well established by scientific investigation. Strength of muscle, control of the nervous system, susceptibility to, or freedom from dis-ease, etc., are more matters of nutrition and environment than of inheritance. The idea that consumption, alcoholism, etc., are inherited, or that the education or training of parents along certain lines will result in children with faculties adapted to similar education, is not in accordance with scientific knowledge.

SUMMARY OF FACTS REGARDING SEX AND HEREDITY

The function of sex has been developed in the process of evolution for the purpose of perpetuating life.

The sexual functions are very closely related to the life of the individual, and can be normal only when the laws of nutrition and of general hygiene are observed.

The idea of prenatal culture as commonly taught is a delusion; the only method that the mother can employ to control the growth of her unborn child is to live a wholesome, normal life, physically and mentally, and thus supply her own body and that of the child with perfect material for the building of living cells.

The powers of heredity are often overestimated, and many of the weaknesses and disorders of life supposed to be inherent can be overcome by proper nutrition and environment. All life, whatever be the inherited tendencies, will be developed to the highest possible capacity by obeying the laws of individual growth, for in the individual, as in the race, Nature is always striving to bring the products of her work to the highest degrees of perfection.