In many children the condition is only discovered at autopsy since the lesions have not sufficiently progressed during life to attract attention. It must be emphasized that although the diagnosis rests only upon the manifestations in the skeleton, rickets is a disease of the entire organism and not of the bones only. The children exhibit signs which can only mean that the whole body is involved in the physiological process. They are nervous and irritable, but usually are apathetic and disinclined to play. They sleep poorly. The muscles are flabby, wasted and weak. This is not only true of the voluntary muscle but also of the smooth muscle of the gastro-intestinal tract. The ligaments are loose and lax. The children perspire freely, especially about the head (head sweats). Frequently the head is continually rolled from side to side on the pillow so that the hair may be worn off from the back of the head. There is often a more or less marked secondary anemia.

The disease may exist without symptoms. Those which are found result from the abnormality of the bony structures and the feebleness of the musculature. The children sit, stand and walk at much later periods than normal children. Although they have as much opportunity for exercise as the normal child, they do not profit by it. Weakness of the abdominal and intestinal musculature results in accumulation of gas in the intestine, and distention of the abdomen (pot belly). The teeth are late in making their appearance and decay early.

The bones are widely affected. Rickets is more severe, often, in some bones than in others, but in advanced cases every bone in the body is involved. Those that grow most rapidly suffer first. The bones of the skull and ribs are attacked early. Among the earliest signs of rickets are areas of softening in the bones of the skull (craniotabes). The junctions of the bony ribs with their cartilages become enlarged. The softened ribs are bent by atmospheric pressure and by the traction of the diaphragm during breathing so that a deep groove is formed in the chest wall along the insertion of the diaphragm. The long bones become bent and are swollen at their extremities. Bow legs and knock knees and sabre shins result from bending of the softened bones, and the wrists and ankles are swollen. On the bones of the skull masses of soft tissue beneath the periosteum give rise to the appearance of the so-called bosses or swellings. The fontanels are slow to close. In severe cases the bones may fracture or the head of the bone may be separated from the shaft. The spine may be twisted and the pelvis distorted. The resistance of these children to infections is lowered and they have sometimes an almost continuous coryza. This lowered resistance together with the deformities of the chest make them very liable to attacks of bronchitis or bronchopneumonia; which frequently are the direct cause of death.

While the death of rachitic children is usually due to some intercurrent infection, severe rickets may be fatal of itself as Park and Howland (1) have pointed out.