all agree, but there is much difference of opinion as to the causes themselves. They appear to fall into two groups which, for purposes of discussion, we will call (1) incidental, and (2) intentional.

Migrations

Foremost in the incidental group we may place the vast recent migrations to the newer areas of earth which have left a surplus of women in the homelands and caused a scarcity of them on the frontier. No woman on the American frontier was without chance of marriage; many New England women found no men of their own group available. This is even more true of Europe. Temporarily, at least, this migration increased the percentage of the unmarried. This has been the result also wherever men have been gathered in military training camps or armies for several years. To some extent it is seen where occupations like commerce have taken men away from home for long periods. Marriage has been delayed, at least, in all these cases. The necessity of supporting parents or other relatives has often interfered with marriage.

Celibacy

Celibacy, however, may be the result of some ideal and thus fall into the intentional group. It appeared as a religious ideal in the old Roman Catholic Church though it was not strictly enforced among the priests until about the year 1000. In view of the great number of able men and women who have come from the homes of Protestant ministers in such numbers as to cause wide comment, the enforced celibacy of priests and nuns takes on added meaning. In some instances celibacy is due to the refusal of some high-minded man or woman to perpetuate known heritable defects. How common this has been no one can tell. Celibacy may come from far more selfish motives: the desire to be free and

independent, the refusal to assume the burden of bearing and rearing children, whether the reasons alleged be financial, social or religious, for Tertullian said that "no righteous man would willingly have desired sons."

Childlessness

Celibacy and childlessness are, of course, quite distinct. The absence of children in some families is wholly due to physical incapacity, but the courts seldom find that this is the actual cause of a divorce suit. The commonest involuntary cause appears to be venereal disease. Hyde of Chicago saw some 1,700 cases of syphilis in pregnant women: 578 (34 per cent) resulted in miscarriages or stillbirths; 956 living children were born only to die within the first twelve months. That is, 1,534 (90 per cent) of the 1,700 offspring did not live a year. Many of those surviving longer were crippled by the disease. A German physician reported on 153 cases where the father was syphilitic; 120 were stillborn; 25 died shortly after birth; only 8 (5.3 per cent) lived over a year. While these figures are extreme there is general agreement that syphilis destroys over 50 per cent of the children. Syphilis, however, does not ordinarily produce sterility. This rôle is played by gonorrhea, a more common disease, which causes over 50 per cent of the involuntary childless marriages in the opinion of medical men. A few. other diseases like measles and mumps occasionally cause sterility. Exposure to venereal disease is generally increased by the social arrangements above mentioned which delay marriage.

Abortion

Abortion is common both in Europe and America, not only in cases of illegitimacy but as a regular practice of some families. The estimates for abortion in the United States range from 250,000 to several million per year. This

may be compared to the total of births, about 1,500,000. Abortion seems to be as common in Germany as here, to say the least, while in France it is said to equal the birth rate. Popenoe feels that it is increasing.15

Contraception

There are few who question the statement that voluntary avoidance of conception is the chief cause of the low birth rate of the educated classes in all western countries. Even the Roman Catholic Church does not oppose family limitation brought about by self-control. It holds, and this is the position of the law of some countries, that contraceptive devices should not be sold, nor physicians allowed to instruct patients even on health grounds. Despite this attitude there is little doubt as to the facts. In Holland the poorer classes have been taught methods of contraception under public auspices with results said to be beneficial. A change of sentiment elsewhere is evident as is shown by the increase in clinics and in public discussions. Entirely apart from the merits of the argument, the amusing fact remains that the immediate results of wider information would probably increase, not diminish, the differential birth rate. The diagram opposite seems to furnish adequate evidence as to the present situation.16

PROBLEMS OF SOCIAL CONTROL

Prohibition

In the chapter on Race Differences it was noted that diseases attack some races more than others. Whether this is due to some original quality of the body or to some immunity acquired by long contact with the disease involved is disputed. Certain it is, in some cases, that the resistance varies with the length of exposure. Hence it has been argued that children ought to be exposed to many diseases lest they take them in later life with more serious results.

FIG. 36. THE FAMILIES OF 461 AMERICAN SCIENTIFIC MEN

The figures at the bottom indicate the number of children to a family; those at the left the number of families of equal size. The chart shows for each size of family of 461 American men of science in how many cases the limitation was involuntary and in how many cases it was voluntary. The shaded areas, showing the number in which it was voluntary, are subdivided to indicate the causes. Thus, when the marriage was childless, this condition was involuntary in 67 cases and voluntary in 35 cases. The reasons assigned were health in 25 cases, expense in 5 cases and other causes in 5 cases. In the family of two, the limitation was voluntary in 84 out of 98 marriages. The reasons assigned were health in 44 cases, expense in 29 cases and inconvenience or other causes in II cases.

This has been a common practice here as regards measles and chickenpox. The public health movement has been condemned as allowing the survival and reproduction of nonresistant stocks. The same argument has been applied to efforts to forbid the use of drugs. The use of alcohol as a beverage has been opposed because it was said to injure the germ cells and lead to the production of abnormal types. The evidence of this race injury by alcohol, as earlier noted, is far from satisfactory. If alcohol could cripple a race it is hard to understand why so many of us are normal, for intoxication was far from rare among our ancestors. Alcohol does affect some folks more than others. Hence

a few men, like G. A. Reid in his thought-provoking work, Alcoholism, are inclined to favor what has been called, "an open-door-to-hell" policy. Reid argues that in groups long accustomed to the use of alcohol, like the Jews, the susceptible types have been killed off, leaving resistant stock not likely to be injured. By contrast the Irish to whom adequate supplies of alcohol are more recent still suffer greatly. The prohibition program then is all wrong. Physicians know that some deep-seated disorder is often the start of alcoholism and that the latter is as often a result as a cause, but present thought does not seem to favor Reid's ideas. The opposition to alcohol, opium, peyote and other drugs is growing and tobacco even is being attacked. Tea and coffee will come next, for the fires of reform demand fuel. The thoughtful observer will note that the antagonism is now based on considerations of health, which are quite apart from the older attitude that anything enjoyable must be wrong.

War

It is doubtful if any human program has been more extravagantly praised and condemned than war. On the one hand it has been lauded as the divinely ordained method of