Its application to society is obvious: Since the propagation of human beings goes on with entire recklessness as to the quality of the product and the means of subsistence, some strong corrective is absolutely necessary to establish limits to populations and to secure the continued development of the race.

If every begotten child lived to the average age of 40, in a very few years there would not be standing room on the earth for its people.

Even with such limited propagators as the elephant, each female of which produces but six offspring in her bearing [{14}] period of 90 years, we are told that if the species had no parasitic or other enemy it would only be 740 years until elephants would overrun the earth.

Where then should we assign limits to the productiveness of the 750,000,000 human females on the globe, each of whom is capable of producing 20 children in her 30 years of bearing?

If, too, every child had the same chance of life without reference to its mental and physical fitness to live, humanity would soon become a stagnant slough of vicious vitality. There are only food and room for the best, and as the development of the race demands [{15}] it, only the best survive and continue the work of propagation. The rest are destroyed.

BY the “best” is understood those having that harmony of mental and physical development which brings them most nearly into accord with Nature’s laws.

BELOW the human stratum superabundant generation is neutralized by the simple device of having [{16}] every organism prey upon some other one. In her 10 years of fruitful life the female cod lays 50,000,000 eggs. If nothing thwarted the amiable efforts of herself and offspring to multiply and replenish, they would shortly pack the ocean as full as a box of sardines.

While, however, giving one female the desire and capacity to produce 50,000,000 lives, nature has given other animals the desire and capacity to annihilate most of those 50,000,000 lives.