were of doubtful ability would be clearly unjustified, and yet this sort of reasoning about the frequency of deficient delinquents has been all too common. Gilliland[24] tested one hundred male inmates of the Columbus, Ohio, Workhouse (28 negroes) selected so as to attempt to represent the different offenses about in their proportions. He gives the results in point scores with the Yerkes-Bridges scale, which may be translated only roughly into Binet 1911 ages by Haines' data, as I have indicated for the study by Rossy. All were 18 years of age or over, so that I estimate 14% would fall into our presumably deficient group including only the proportion of those under 64 points who would test as Binet IX or less. The doubtful group would include 17% more, including the proportion under 66 points who would test X or under. Among the local institutions supported by the county or city, the most serious delinquency is probably found in the group reported by Kohs at the Chicago House of Correction (_33_). He tested with the 1911 Binet scale 335 consecutive cases between 17 and 21 years of age. Among these were 72 cases (21%) who tested clearly deficient according to our standard, and 95 cases doubtful, a total of 50% at least uncertain in intellectual ability. Through the courtesy of Catherine Mathews, who made the examinations for the psychological clinic of the University of Pittsburgh, which is under the direction of Dr. G. C. Bassett, I am able to give the records of 125 consecutive admissions to the Allegheny County Detention Home. The institution is known as the Thorn Hill School. It is situated some miles outside of Pittsburgh and provides on the cottage plan for about 300 boys. The boys are sent from the Juvenile Court for milder training than that at the state school. The school has also been found to furnish a necessary place to care for cases of feeble-minded delinquent boys who cannot be immediately admitted to the state institution on account of its crowded condition. A detention home is also provided in the city for juvenile court children awaiting trial or the disposition of their cases. These are not included in the Thorn Hill group. Among the 125 consecutive cases at Thorn Hill, omitting two cases which are probably dementia praecox, there were 37, or 29%, who tested presumably deficient according to our standard, and a total of 68 cases, or 55%, presumably and doubtfully deficient. It is to be remembered that our standard for the immature was arranged for the 1908 scale and not the 1911 scale which was used here, although the difference would be slight. TABLE X. BINET 1911 TESTS OF BOYS CONSECUTIVELY ADMITTED TO THE ALLEGHENY COUNTY DETENTION HOME AT THORN HILL. (MATHEWS)