This estimate would make the maximum number of all degenerates 5.54 per cent of the population. From these must be deducted those who are not congenital. We can estimate the congenitals by three methods: by statistics of _atavism_, or _consanguinity_, and by _experiment_. In the statistics of atavism we add together the physical abnormalities of the individual, assuming that a criminal type is found when these abnormalities reach the number of three or more. The statistical method always suffers the limitation that it indicates not identity, but probability. Yet it has an important value, provided it discovers ratios of probability which concur. This is not the case in the method by atavism. Sixty to seventy per cent of criminals do not belong to the assumed criminal type; and sixteen per cent of normal males are classed as criminals, whereas the actual number is less than three per cent of the males of criminal age. (See Lombroso, "The Female Offender," pp. 104, 105.) While atavism itself is unquestioned, this method seizes upon rigid physical characters to measure educable qualities. And where the latter are themselves abnormal the causes may lie with education and not heredity. The method by consanguinity seeks not the abnormalities of the patient himself, but the signs of disease and degeneracy in his blood relatives. It therefore greatly increases the apparent weight of heredity, for it collects symptoms from several individuals instead of one. The medical authorities ascribe fifty to eighty per cent of inebriety to heredity. This method fails as does the other, for, as seen in the Jukes or the drunkard, the child gets both its heredity and its education from the same degraded parents, and the method provides no measure for separating the two. In sociology the method of experiment has but limited employment. The modern sociologist cannot mate the parents nor vivisect the soul, after the methods of the biologist. He can only move the child from one education to another, and his experiment is incidental to the larger purpose of saving the child. His results, too, can appear only as a ratio of probability; but this ratio measures the mental and moral qualities themselves directly and not by inference. Elmira Reformatory and others cure eighty per cent of their charges. Model placing-out institutions and free kindergartens save nearly all. And these are taken from the most vicious and criminal parentage in the land. Our five and one-half per cent of degenerates must therefore be greatly reduced in order to find the residuum of congenitals. I have made the following deductions: ESTIMATED DEFECTIVES NOT CONGENITAL, PER MILLION POPULATION.