The number of patent feeble-minded in the United States is probably not less than 300,000, while the number of latent individuals--those carrying the taint in their germ-plasm and capable of transmitting it to their descendants, although the individuals themselves may show good mental development--is necessarily much greater. The defect is highly hereditary in nature: when two innately feeble-minded persons marry, all their offspring, almost without exception, are feeble-minded. The feeble-minded are never of much value to society--they never present such instances as are found among the insane, of persons with some mental lack of balance, who are yet geniuses. If restrictive eugenics dealt with no other class than the hereditarily feeble-minded, and dealt with that class effectively, it would richly justify its existence. But there are other classes on which it can act with safety as well as profit, and one of these is made up by the germinally insane. According to the census of 1910, there are 187,791 insane in institutions in the United States; there are also a certain number outside of institutions, as to whom information can not easily be obtained. The number in the hospitals represented a ratio of 204.3 per 100,000 of the general population. In 1880, when the enumeration of insane was particularly complete, a total of 91,959 was reported--a ratio of 188.3 per 100,000 of the total population at that time. This apparent increase of insanity has been subjected to much analysis, and it is admitted that part of it can be explained away. People are living longer now than formerly, and as insanity is primarily a disease of old age, the number of insane is thus increased. Better means of diagnosis are undoubtedly responsible for some of the apparent increase. But when every conceivable allowance is made, there yet remains ground for belief that the proportion of insane persons in the population is increasing each year. This is partly due to immigration, as is indicated by the immense and constantly increasing insane population of the state of New York, where most immigrants land. In some cases, people who actually show some form of insanity may slip past the examiners; in the bulk of cases, probably, an individual is adapted to leading a normal life in his native environment, but transfer to the more strenuous environment of an American city proves to be too much for his nervous organization. The general flow of population from the country to large cities has a similar effect in increasing the number of insane. But when all is said, the fact remains that there are several hundred thousand insane persons in the United States, many of whom are not prevented from reproducing their kind, and that by this failure to restrain them society is putting a heavy burden of expense, unhappiness and a fearful dysgenic drag on coming generations.