While this lack of adjustment is undoubtedly the most pressing _training_ problem connected with juvenile delinquency, we must not expect that when it is solved we shall have eliminated the problem of mental backwardness of delinquents as a class. The most that we could expect from perfect adjustment of the school work to mental ability would be that the average amount of school retardation for the group would be materially reduced. How much retardation in school relative to the life-ages would still remain, cannot be determined on account of the uncertainty of the tests for older ages and the factor of volition. For the mentally deficient pupils still remaining behind the regular pupils it is necessary to provide other special classes. In these classes or schools the feeble-minded children would remain for their entire school course. That the correction of the lack of adjustment is a much more agreeable and hopeful task than the care for deficients is shown by the facts regarding the detention home group in Table IX. There is at least the possibility that 10 of the school laggards in this group of serious delinquents might be brought up to a satisfactory grade. Discount this prospect as you may, it is still to be compared with the fact that no actually feeble-minded boy can ever, by special instruction, be brought up to a satisfactory school grade. Moreover, we might expect that 30 of the 84 laggards might, by special help, catch up one or more grades. That the correction of lack of school adjustment is a bigger problem in connection with juvenile delinquency than the detection and isolation of the mentally unfit can only be said in relation to the numbers affected. Taking the lowest estimate of those in the detention home group out of adjustment with their school environment it was at least 30, while only 9 of that group fell below the borderline of passable intellects and only 2 were surely feeble-minded. If one guessed as we have on the basis of school position that a maximum 6% of the ordinary juvenile delinquents in Minneapolis might be feeble-minded, who would venture to guess that ill-adjustment of school to mental ability affects so small a proportion? On the other hand one feeble-minded person, through the transmission of his deficiency, may, perhaps, do more damage to society than many intelligent delinquents. Who shall say? Certainly both the isolation of the feeble-minded and the adjustment of school training are vitally important problems in the care of juvenile delinquents today. Nobody can say that one is more important than the other except from a special point of view. From the eugenics standpoint feeble-mindedness is more important; from the point of view of the numbers affected and the skill required for training the child, there can be little question but that the correction of bad adjustment to school environment is the bigger problem. When one considers how much of the child's time is spent