In the first of the books to which I have just referred, Dr. Healy presents in detail the cases of over three hundred children who were sent to him as a physician and medical psychologist by the judge of the Juvenile Court in Chicago, who requested Dr. Healy to aid him in his legal treatment through a medical and psychological study of each case. Dr. Healy with his corps of assistants and social workers studied in each child the physical condition, especially the presence or absence of defects of sight and hearing, and the mental condition carefully measured by tests based upon those of Binet, but extended considerably by Dr. Healy himself and by others. But he adds to the facts thus ascertained a careful investigation of the child's social environment, both physical and psychological; that is, of all the influences--hereditary, domestic, economic, industrial, and personal--which have contributed to lead the child into crime. The influence of other boys and girls of the same age, of associates in work or school, is investigated; also the good or bad example of parents, the amount and quality of schooling, and the presence or absence of religious instruction. All these latter investigations are carried out for Dr. Healy by social workers. Their results are then pooled with those obtained by him after the physical and psychical examination of the child at the dispensary. One sees, then, that Dr. Healy and the other Americans who have followed him in this field, insist upon covering in every case four classes of facts: (1) The child's physical condition. (2) The child's mental condition. (3) His physical environment. (4) His mental, moral, and spiritual environment. All this investigation is necessary because it is now recognized that crime may be committed because the child is an epileptic; because he is feeble-minded; because he is strained and tortured by defects of sight and hearing; by inability to keep up in school on account of these defects; because he is abnormally susceptible, under the influence of comrades, cinema shows, and sensational literature; because his inheritance, his education, or his home training has been defective or bad. Since there is no reasonable doubt that physicians and judges will more and more coöperate in the study of offences against the law, and will more and more need the assistance of social workers to complete their studies and to carry out the reforms which those studies suggest, it can easily be appreciated that the social workers need to be familiar with the methods and results of psychological examination in this field of work. _Mental diagnoses in social work_