The study of the anatomy of the brains of idiots is a vast field accessible to research, which may serve to throw light upon some questions of psychiatry, hitherto obscure, but which possess an undeniably practical value. It ought to enable us to comprehend better the questions which relate to hereditary insanity. It is undeniable that the vices of physical conformation of ancestors are transmitted to their descendants, and that this phenomenon is the point de depart of pathological varieties.