Fortunately, some of these writers are already beginning to qualify and modify their views, and some of these statements misstate the idea of the investigators, but it is difficult to correct the impression that has been gathered from those who speak with authority. In the face of the fact that mental deficiency is undoubtedly the most important single factor to be considered today in the institutional care of delinquents, one hesitates to correct even the most exaggerated impressions as to its importance. On the other hand, it seems time to modify opinions which raise false hopes as to solving the problem of delinquency by caring for the feeble-minded. Above all it is important to lay a surer foundation on which a platform for the social care of these unfortunates may be securely built. In the first place, it is necessary to recognize that after all the feeble-minded are properly cared for by society the problem of the ordinary delinquent may still remain with us in much of its present proportions. Surely the isolation of the deficient children will hardly scratch the surface of the problem of first offenders as it comes before the juvenile courts of the country. To this it should be replied that the first offenders are not, after all, the troublesome cases before our courts. If we study the different groups of delinquents which have been tested, we notice that they represent highly selected groups among the ordinary offenders whether these be adults or minor delinquents. The only parallelism which can be traced at all is between prostitutes and vagrants and some of the institutional groups. We should stop assuming that the institutional delinquents represent the ordinary offenders. The present evidence points to the conclusion that it is the repeaters, not the first offenders either in the juvenile or criminal courts, who are most likely to be deficient. Nevertheless, 68% of the boys brought before the Chicago Juvenile Court during its first ten years were first offenders (_142_), while 89% of 4143 boys in the Juvenile Court in Minneapolis were first offenders (_105_). We know almost nothing about the frequency of deficiency among the first offenders brought before our courts and yet the bulk of delinquents are undoubtedly first offenders.