The author's line of reasoning runs something as follows: The race is degenerating physically, as is shown by the increasing amount of illness, the rejections of recruits for the Army and Navy, the number of deaf and blind. He estimates the number of those affected with temporary or permanent physical disability as one in five. Mental degeneration is shown by insanity, criminality, vice, etc., and the number of cases is estimated at one in fifty, although, perhaps, this is too low. The causes of degeneracy are put as the intermarriage with lunatics, idiots and feeble-minded persons, child marriages, forbidding or restraining the healthy from marriage, encouraging the marriage of the unfit, release of asylum patients before recovery, overwork of the young brain, unsuitable employment for women and children, abuse of alcohol, undesirable immigration, venereal diseases, abortion and sexual excess. The legal restrictions of marriage in various countries