More precise investigation has shown since that this estimate was under the mark. Dr. Tredgold, who in England has most carefully studied the heredity of the feebleminded, found that in over 82% there is a bad nervous inheritance. Heredity is the chief cause of feeblemindedness, and Tredgold has never seen a normal child born of two feebleminded parents. The very thorough investigation of the heredity of the feebleminded which is now being carried on at the institution for their care at Vineland, N. J., shows even more decisive results. By making careful pedigrees of the families to which the inmates at Vineland belong it is seen that in a large proportion of cases feeblemindedness is handed on from generation to generation, and is transmissible through three generations, though it sometimes skips a generation. Not only is feeblemindedness inherited, and in a much greater degree than has been hitherto suspected, but the feebleminded tend to have a much larger number of children than normal people. The average number of children of feebleminded people seems to be usually about one-third more than in normal families, and is sometimes very much greater. Page 26–36. And it is not only in themselves that the feebleminded are a burden on the present generation and a menace to future generations. They are seen to be often a more serious danger when we realize that in large measure they form the reservoir from which the predatory classes are recruited. This is for instance the case as regards the fallen. Feebleminded girls of fairly high grade may often be said to be predestined to immorality if left to themselves, not because they are vicious, but because they are weak and have little power of resistance. They cannot properly weigh their actions against the results of their actions, and even if they are intelligent enough to do that, they are still too weak to regulate their actions accordingly. Moreover, even when, as so often happens among the high grade feebleminded, they are quite able and willing to work, after they have lost their respectability by having a child, the opportunities of work become more restricted and they drift into prostitution. Criminality again is associated with feeblemindedness in the most intimate way. Not only do criminals tend to belong to large families, but the families that produce feebleminded offspring also produce criminals. P. 40. Closely related to the great feebleminded class, and from time to time falling into crime are the inmates of workhouses, tramps and the unemployable. The so-called able-bodied inmates of our workhouses are frequently found on medical examination to be more than 50% cases of mental defectives, equally so whether they are men or women. P. 42.