Investigations on the thymus of the new-born, as presented in this communication, were undertaken with the idea of solving certain problems connected with the thymus, of paramount importance to the obstetrician. The latter has charge of the new-born infant for at least two weeks following delivery. After the mother is up and about, he may, if he chooses, turn the infant over to the pediatrician. However, during this interval, with very few exceptions, the welfare of the new-born infant is his responsibility, and cannot be shifted. He must ever be on the alert to detect in the new-born infant signs of thymic disturbance. Ignorance or carelessness in this regard will no longer be excused, since it is becoming a part of common knowledge that babies
often die from some disturbance of this gland. Then, too, in this day and age of preventive medicine, the welfare of the child is quite