For the last seven years the routine physical examination of children in this institution has included a special survey for rickets. These examinations have been carried out almost every month on infants under 18 months of age and the data recorded on separate forms. In addition to noting the presence or absence of purely clinical signs, a radiograph of the epiphyses of the wrist has been included for the last five years, and an estimation of the inorganic phosphate of the blood for the last three years. In the course of these routine tests our attention has frequently been directed to the great variability in the resistance or pliability of the chest wall. When downward pressure is exerted on the anterior thoracic wall, the thumbs being placed on the manubrium of the sternum, there is a greater or less degree of yielding of the ribs. In some cases the costal