The population of a locality is brought together almost entirely by natural selection. It is by individual telesis rather than social telesis. A small institution, such as an industrial establishment or a school, selects its population to some extent; it advertises for the kind of people it wants and keeps out the kind it does not want by setting entrance requirements. But each person who joins does so for reasons of his own. Though the members rarely comprise all the population of a locality, yet in general the larger the institution the more it is obliged to admit the people who are at hand without selecting, and then to keep those who once become members until they withdraw of their own choice. The state excludes very few of the aliens who wish to immigrate, and of those once admitted gets rid of still fewer by deportation or capital punishment.

The democratic movement, reŽnforced by the precepts of Christianity, has done much to promote the conservation of human life. Compelling an employer to compensate an injured workman makes him regardful of the safety of his employees; "Safety First" becomes the watchword. There is a "Bulletin on Safety Instruction in Schools," issued by a state superintendent, intended especially for boys and girls in continuation schools. It describes twenty-five dangerous practices or causes of accidents, with appropriate warnings. There is a National Safety Council which has prepared a Safety Primer and will lend the plates of the book without cost to any city or state desiring to use them.

The use of social telesis to preserve health is now so familiar that a mere enumeration of some of its forms will suffice:

Instruction in hygiene in public schools; medical education in the state universities; state examination and license for physicians and pharmacists; regulation of building with reference to safety and sanitation; control of water supply; segregation of persons suffering from contagious diseases; inspection of foods to prevent unwholesome adulteration.

In regions that are sparsely settled but rich in resources there is likely to be concerted effort to increase the population by attracting immigration. Public opinion approves of early marriages and large families. In densely populated regions, on the other hand, the opposite conditions exist. What will be done when the entire world becomes so densely populated as to press upon the food supply and there are no more fertile lands to which to emigrate? It is difficult to foresee with any certainty, though easy to think of many things that may be done.

The most rational thing to do - and without waiting for the overcrowded condition to come - is to exercise telic selection upon the population toward improving its quality. The immigration laws of the United States prohibit the entry of defective persons, and require the deportation, at the expense of the steamship companies bringing them, of any persons who are found to be defective within one year after landing. On the statute books of the states - some of them, at least - are laws prohibiting the marriage of defectives. Some states segregate them in institutions, and a few permit or require their sterilization. Restraint is clearly justified with persons possessing a hereditary defect as serious as feeble-mindedness, especially since they reproduce twice as rapidly as normal persons do. In early times the proportion of defectives was kept down by disease, starvation, and the prevalence of capital punishment for all sorts of crimes. Now that society is banishing such causes of death, the only rational course is to prevent hereditary defectives from reproducing. The half-heartedness and ineffectiveness of the measures already taken to that end are due to doubt as to just what defects make a person a useless member of society, and as to whether or not these defects are heritable. It makes us pause to see a person who was once considered feebleminded turn out a genius. But these doubts are being settled by scientific investigation. When that is once done, a thorough application of preventive measures could eliminate the hereditary defectives in one generation. The elementary schools will have the important share of discovering the defectives, first through the regular grade teachers and principals, and finally through expert examiners. In time, increasing density of population will naturally raise the limit of the proscribed unfitness.

Whether society will ever agree upon an ideal type of human nature and sanction any method of selective breeding toward it, is a question which has so far been kept in the background. As far as biological factors are concerned, it would be entirely practicable to counteract the tendency of enlightened peoples to die off at the top. Social arrangements, however, have usually worked in the opposite direction. Enforcing celibacy on those engaged in any occupation tends to eliminate in the general population the qualities required in those who follow that occupation. To require that teachers be unmarried is to hasten the day when there will be no naturally gifted teachers. Now that the working of the hereditary factor is becoming better understood, more intelligent counsels will doubtless prevail in the future, seeking to better conserve the preferred strains in the population and perhaps even multiply them. There are already competitive exhibits of "Better Babies" and "Better Boys." In 1914 there was held at Battle Creek, Michigan, a National Conference on Race Betterment. In 1912 was held in London the First International Eugenics Congress.

At Cold Spring Harbor, Long Island, New York, is the Carnegie Station for Experimental Evolution. To work in affiliation with this the Eugenics Record Office was established in 1910. The chief purpose of the latter is to "build up an analytical index of the traits of American families." Other purposes, subsidiary to this, are giving advice in regard to proposed marriages, cooperating with other institutions in the study of eugenics, training field workers for other institutions and to conduct its own studies, and making itself a general clearing house for the study of human heredity in America. Anyone interested should write for fuller information.