It is obvious from a review of the literature that the coexistence of changes in bone with disease of the parathyroid glands has long been noted. In brief, the predominating osseous changes described are generalized atrophy and multiple cystic lesions. It is noteworthy, however, that when roentgenograms from cases of hyperparathyroidism are compared, certain fundamental and predominating structural changes are revealed in the osseous system which are so strikingly similar and constant that in a preliminary report concerning this subject Ochsner and I1suggested a characteristic roentgenographic picture for hyperparathyroidism. Since publication of these preliminary observations, Jaffe and Bodansky,2and Johnson and Wilder have reproduced in animals, by the injection of parathyroid extract, osseous changes that are identical, histologically and roentgenographically, with the changes observed in the cases reported by us. Clinically and experimentally these fundamental changes can be altered and restoration toward normal produced by the removal