At a certain stage of the evolutionary process, Nature seems to have awakened to a realization of the fact that it was better, from every point of view, to produce a few superior beings rather than a vast number of inferior ones. Here, at last, Nature discloses a heretofore hidden aim, namely, the production of quality rather than quantity; and once she has started on this new path, she has pursued it with even greater eagerness than that of reproduction pure and simple. And here we pause to note a principle laid down by the students of Evolution, viz., that advancing evolution is accompanied by declining fertility.
This new stage of Nature's processes is marked by a constant and invariable manifestation of diminished number of offspring, accompanied by an increased amount of time and care in the creation and breeding of each of the young creatures. Accompanying this, we find that the reproductive life of the creature is shortened, and confined to more or less special periods; these periods beginning much later, and ending much earlier, and even during their continuance tending to operate in cycles of activity. Here, we see, Nature, grown wiser by experience, herself began to exercise her power in the direction of Birth Control—the use of preventive checks on reproduction.
A writer has said along these lines: "As reproduction slackened, evolution was greatly accelerated. A highly important and essential aspect of this greater individuation is a higher survival value. The more complex and better equipped creature can meet and subdue difficulties and dangers to which the more lowly organized creature that came before—produced wholesale in a way which Nature seems to look back on as cheap and nasty—succumbed helplessly without an effort. The idea of economy began to assert itself in the world. It became clear in the course of evolution that it is better to produce really good and highly efficient organisms, at whatever cost, than to be content with cheap production on a wholesale scale. They allowed greater developmental progress to be made, and they lasted better. Even before man began it was proved in the animal world that the death-rate falls as the birth-rate falls."
Let us compare the lowly herring with the highly evolved elephant. The herring multiplies with enormous rapidity and on a vast scale, and it possesses a very small brain, and is almost totally unequipped to grapple with the special difficulties of its life, to which it succumbs on a wholesale scale. A single elephant is carried for about two years in its mother's womb, and is carefully guarded by her for many years after birth; it possesses a large brain, and its muscular system is as remarkable for its delicacy as for its power, and is guided by the most sensitive perceptions. It is fully equipped for all the dangers of life, save for those which have been introduced by the subtle ingenuity of modern man. Though a single pair of elephants produces so few offspring, yet their high cost is justified, for each of them has a reasonable chance of surviving to old age. This contrast, from the point of view of reproduction, of the herring and the elephant, well illustrates the principle of evolution previously referred to. It brings clearly into view the difference between Nature's earlier and her later methods—the ever increasing preference for quality over quantity. Unless we grasp this underlying principle of Nature in its wider aspects we may fail to perceive its operations in the case of man, which latter we may now consider.
It is, of course, impossible to speak positively regarding the birth-rate and death-rate of the pre-historic primitive races of mankind, for there is not data upon which to base such a report. But reasoning upon the basis of conditions existing among the primitive tribes of the present time we are justified in holding that in the early stages of the evolution of the race there was manifested a high birth-rate and a correspondingly high death-rate. Upon the basis of conditions now existing among savage tribes it would appear that primitive man has a higher birth-rate than the average of mankind today, and likewise a higher death-rate. The rapidly increasing number of children born to the tribe was counteracted by deaths among children caused by neglect, poverty, and disease. In some cases the population was prevented from becoming larger than the means of subsistence justified by the practice of infanticide.
As to the condition of the race in the early stages of "modern" civilization, we have modern Russia as a surviving instance of this stage. In modern Russia we find, side by side with the progress in neighboring nations, conditions which a few centuries ago existed all over Europe. Here we have an enormous birth-rate, and a terrible death-rate caused by ignorance, superstition, insanitation, filth, bad food, impure water, plagues, famines, and other accompaniments of overcrowding and misery. We find a mortality among young children which sometimes destroys more than half of the children born before they have attained the age of five years. As high as is the Russian birth-rate, it is a matter of record that at times the death-rate has actually exceeded it. And among the survivors there is found a startlingly large percentage of chronic and incurable diseases, with a large number of cases of blindness and other defects.
Similar results follow in China, where the birth-rate is exceptionally high, and the death-rate correspondingly large; and where there is a large percentage of inferior physical development and pathological defects, the evil conditions which produce death also tending to produce deterioration in the survivors. In both of these countries we have an example of the result of unrestricted reproduction, and unrestricted destruction—as among herrings, so among men. And yet this condition of unrestricted reproduction is the logical goal of certain persons who, inspired by the best possible intentions, in their ignorance and criminal rashness would dare to arrest that fall in the birth-rate which is now beginning to spread its influence in every civilized land.
In Western Europe before the nineteenth century the population increased very slowly. The enormous birth-rate was nearly equalled by the exceedingly heavy death-rate caused by plagues, pestilences, and famine, and by the frequent wars large and small. The mortality among young children was particularly heavy. Writers have pointed out that the old family records show frequently two or three children of the same Christian name, the first child having died and its name given to a successor.
During the last quarter of the eighteenth century, when machinery was introduced and a new industrial era opened, the birth-rate rose rapidly. Factories springing up gave increased support to many, and as children were employed as "hands" in the mills at an early age, the richest family was the one with most children. The population began to increase rapidly. But soon disease, misery, and poverty arose from filth and insanitation, immorality and crime, overcrowding and child-labor, drink and lack of sane courses of conduct.
In time, however, progress set in, and social reformers began the great movement for the betterment of the environment, sanitation, shorter hours of labor, and restriction of child-labor, factory regulation, etc. And when the environment is bettered, the death-rate drops, and the birth-rate accompanies it on its downward progress. As Leroy-Beaulieu says: "The first degree of prosperity in a rude population with few needs tends toward prolificness of reproduction; a later degree of prosperity, accompanied by all the feelings and ideas stimulated by the reduction of such prolificness."