This is, then, the case of a boy who had a talipes calcaneovalgus of congenital origin. The malposition was noticed at the time of birth. When a little more than one and one-half years old he was examined in our clinic for the first time, the calcaneovalgus position being then marked, and exceedingly strange changes in the astragalus being detected by x-ray examination. The foot was corrected, but five years later it exhibited a marked recurrence of the trouble and the ankle joint is now practically ankylosed. The astragalus seems to be too large for the rest of the foot. The posterior process and also the head of the bone are enlarged in a mushroom-like fashion, and show on the x-ray film an uneven outline and a mottled structure. Operation revealed astragalus markedly nodular in the anterior and posterior parts, an appearance simulating a chondroma. Similar changes were also indicated on the articulated surface of the tibia and the scaphoid. These changes might possibly be explained by the correction carried out five years earlier (e.g. fractures), but against this we have the fact that the x-ray picture showed, in the main, the same changes even before the first treatment.

One cannot help thinking that the changes present here might have a certain connection with juvenile growth disturbances, such as Köhler's disease in the scaphoid and that of Legg-Perthes-Calvé-Waldenström in the head of the femur. The fragmentation and the partly denser bone structure are points in common. The skeletal affection here, however, has been observed at an age when these common growth disturbances are unknown and, furthermore, the histological appearance does not tally.

We seem to be dealing here with entirely unknown changes in the skeleton,—at least the author has not been able to trace anything like it in the literature. The histological examination does not point to any tumorous tissue, nor does one find any necrosis or signs of inflammatory process. Ossification does not seem to be inhibited but disarranged, particularly the ossification zone. A strange feature is the abundant aggregation of endoplasm "balls". The whole cartilaginous tissue is pervaded in the normal manner by chondrin, but the exoplasm contained in the endoplasm "balls" is entirely lacking in collagen and, therefore, resembles histologically the hyalin fiberless cartilage laid down at an early stage during embryonic life, where the collagen is exceedingly sparing in amount or not at all developed. Whether there is a question here of cartilage remaining from an embryonic stage, or a disturbance in the growth simulating a fiberless embryonic cartilage, can scarcely be ascertained; yet one might venture to suggest that it is a question of embryonal tissue elements partly fixed in the tissue.