OSTEOPOIKILOSIS is a comparatively rare disorder which is generally conceded to be an anomaly of the skeletal structure that, because it is usually asymptomatic, is discovered most frequently by accident in the course of roentgenographic examination for evidence of, or for the cause of, other lesions. Albers-Schönberg first described osteopoikilosis in 1915. A man, 21 years of age, came to him for examination because of various pains in one of his shoulders and one of his feet. He had acquired the condition during several months of trying service in the trenches. In civil life he had been an “enamel-burner” and, except for the symptoms just mentioned, he was in good health. Roentgenographic examination elicited, in all parts of the skeleton but the skull, clavicles, scapulæ, spinal column, and patellæ, and almost exclusively in the spongy substance, a peculiar structure consisting of round or oblong, but generally rather closely clustered dense spots that gave the bone a characteristic speckled appearance. These spots varied in size from 2 to 5 cm. in length, and the higher they were situated in the metaphyses the larger and longer they were. They appeared even in the corticalis, but without elevation of the surface. In the small bones of the hands and feet, and especially in the heads of the metacarpal bones, the shape was chiefly round. All the spots were clearly defined. A few of them were not quite compact but, as was the case in a phalanx of the thumb, were ring-shaped, with a lighter center. The longitudinal axis of the spots invariably agreed with the longitudinal axis of the skeletal parts in question, and in the short bones the structures of the bone shafts were generally followed with fair distinctness. Ledoux-Lebard, Chabaneix, and Dessane reported a similar case in 1916, and because of the spotted appearance of the bones they gave it the name “osteopoecilia.” Some thirty-two cases have been reported in the literature, and in these involvement has been noted in the clavicle, scapula, patella, and spinal column; the spottings were less numerous, however, in these bony parts, and they have been in the accessory processes of the vertebræ and not in the bodies. Mascherpa stated that Bistolfi, in 1927, presented the case of a person 21 years of age in which nodules were found in the occipital bone. Other than this no lesions have been reported involving the skull. In August, 1934, an American-born Jew, aged 26 years, came to the Clinic with an indeterminate abdominal lesion and an excessive flatulence which had been present for ten years. This flatulence had been aggravated following an abdominal operation elsewhere four months previously. During routine examination, the patient mentioned that roentgenograms made elsewhere had exhibited some abnormality of the skeletal structure. The patient also stated that an only brother had a similar abnormality of the skeletal structure on similar examination elsewhere.2