The following investigation deals with 400 children (200 boys and 200 girls) between the ages of 7 and 14, considered by the teachers, and after examination by myself, to be dull and backward, but not to fall within the meaning of the definition of feeble-minded as given in the Mental Deficiency Act of 1913—i.e., persons in whose case there exists from birth, or an early age, mental defectiveness not amounting to imbecility, yet so pronounced that they require care, supervision, and control for their own protection, or for the protection of others; or in the case of children, that they by reason of such defectiveness appear to be permanently incapable of receiving proper benefit from the instruction in ordinary schools.