More and more frequently in America the dispensary physician is consulted about the physical and mental condition of children and adolescents who are sent to him from courts. The judges, especially in our juvenile courts, are coming to realize that their legal training, their knowledge of the nature, the evidence, and the prescribed punishments for proved offences, is only a small part of their equipment if they are to deal with juvenile offenders in such a way as to promote the public good. The legal profession is beginning to realize that the physical, mental, and moral study of juvenile offenders is essential if one is to do anything to prevent their offending again. If penology is to be constructive and reformatory, if it is not merely to represent revenge, repression, and intimidation, our judges must know something of medicine and especially of medical psychology. In this field, as in the field of the functional and visceral neuroses, France has furnished the leaders, but apparently these leaders have been insufficiently followed. The work of Binet in the psychological measurements of school-children's intelligence seems to us in America to have been epoch-making. We recognize its limitations, we recognize that in its details it cannot be universally followed. But we have taken up the suggestions and the method of Binet, and gratefully acknowledging our indebtedness to him we have tried to carry these suggestions and methods much further, to apply them to the needs of older children and to the examination of those who cannot read and write. Binet's tests depended altogether too much upon the use of books and upon linguistic facility. Yet with some modifications they seem to us in America to be of the greatest value, and in the remarkable book _The Individual Delinquent_ (Macmillan Co.) by Dr. William Healy, of Boston, and in the books of his associates and followers, the science of medicine and medical psychology are intimately interwoven with the investigations and reports of the social worker.