R. Dupuy.Medicine and Eugenics.443 children as those who simply 'present an intellectual deficiency, but we must equally consider in that category those who either at the same or at different times show a retardation, aù arrest or a regression as well in corporal and sensorial evolution as in psychical. Beyond this, if we consider that these subjects are in process of gjowth, that is to say, in a state of biological instability, if we notice alsc that the types of anomalies are so varied to such a degree that each oftckward child taken in his entirety constitutes a special clinical type, and that it is almost impossible to place him in a general classification—we might then appreciate the difficulties that are experienced in giving an idea of unity to this enquiry. In order to judge of a backward child, we must take account of his age, and proceed by com­ parison. Every child is backward who, for a given age, shows a retarda­ tion in body, mind, or spirit compared with other children of the same age.The new-born child has a vegetative life; the infant has an animal life, which becomes human the moment it is endowed with thought and speech. Puberty appears afterwards ; the subject is then capable of reproducing itself. What a number of stages a child must pass through before arriving at the age of marriage ! Now, to each of these stages there corresponds a whole series of evolutionary troubles which affect the subject either wholly or partially. Backwardness is the most important of these, but there exists also a condition characterised by exaggeration or inversion which we call perversion and deviation. The backward children, properly so-called, only therefore represent a certain number of abnormal children, the rest being subjects of perversion and deviation. Like backwardness, per­ version may be corporal, psychic, or sensorial. It may be in all three spheres, but this is rare. It may be only in one, and may only concern one system, one organ, one faculty, or one sense. This is the case with giants, prodigies of music or memory, juvenile dements, sexual inverts, etc., but very frequently backwardness is accompanied by perversion, or is caused by it ; so much so that infantile backwardness, as we conceive it to-day, is a mixed condition. It is not simply an arrest, a retardation, a regression, an immaturity, but a lack of balance, a disharmony of evolution. The causes of infantile backwardness are many. The condition may be congenital or acquired, sometimes it is mixed. It is congenital in conse­ quence of a weakening of the parental germ (senility, multiple gestations, alcoholism, syphilis, tubercolosis, physiological, poverty, paludism, arthritism, neuropathic condition, etc.). It is acquired in consequence of embryonic maladies, abdominal traumatism, or overstrain of the mother during pregnancy, premature birth, dystocia, whether maternal or foetal, infections of infancy, too rapid growth, or deficiency in nourishment. On this fact, however, we specially insist, that infantile backwardness, whether