The interrelations of the physical and the psychologic aspects of the life of the growing infant and child are of paramount importance. Nevertheless the opportunity to study them is rare, owing in part to the intensive specialization in medicine. The pediatrician, since he is in more or less continuous attendance on the child, has the opportunity of observing the development and course of physical ailments. Through this study he has learned not only to cure but to prevent many of them. Unfortunately the mental hygienist has not the same opportunity to study the development of psychologic disorders for he is called only after they have arisen.
When the attending physician is both a pediatrician and a mental hygienist, he can study the growth of the child completely. This, of course, necessitates not only observing and treating the child, but studying the environment as well. Many observations of this kind should