From the same psychopathic laboratory comes the estimates of Dr. Bronner (_7_) of a group of less serious offenders, some of whom were in court for the first time, a group at the Cook County Detention Home connected with the Juvenile Court in Chicago, where cases are held for trial or until other disposition can be made of them. I have already reported her results with the Binet tests for the girls in this group. Using the same standard which was there described, she found among 337 boys 7 to 16 years of age 7% “probably feeble-minded,” and 2.4% doubtful, a total of 9.4% “possibly feeble-minded.” As nearly as I can tell from the description of the borderline which she used with the tests, a boy was perhaps slightly more likely to be regarded as testing probably deficient than by our standard for the presumably deficient. Inasmuch as Miss Bronner worked with Dr. Healy, this may throw some light on the test standard which he had in mind in connection with his more serious offenders. By means of Bluemel's study of different classes of juvenile delinquents who passed through Judge Lindsay's Juvenile Court in Denver, we are able to compare the intellectual ability of a group which was on probation, about half of whom were first offenders, with groups sent to the Boys' and Girls' State Industrial Schools (_2_). Although the report does not so state, I should judge that the cases were objectively selected. The published data is not adequate to state the results on the basis of our conservative borderlines; but we can note the cases which tested XI or below and were four or more years retarded with the 1911 Binet Scale (Goddard's modification). This only differs from my broadest interpretation by also including those that test XI. On this basis 6 of the 100 probationers were possibly deficient; 9 of the 50 boys sent to the State Industrial School, and 24 of the 50 girls sent to the State Industrial School or Florence Crittenden Home. These are all somewhat excessive estimates of the amounts of deficiency in this group as judged by the interpretation we have been using. A more telling comparison of the mentality of these groups may be made by weighting each retarded case by the tests according to the number of years he is retarded. The amount of retardation alone averages 1.3 years for the group of probationers, 1.8 for the boys at the state school, and 3.8 years of the institutional group of girl delinquents. Fifty first offenders among the probation group average 1.1 years retarded. The girls and the more serious juvenile delinquents in these younger groups show more retardation.