In a study of otosclerosis, Meyer 1 compares the development of the labyrinth capsule with that of the long bones. Up to the period of the development of the marrow space in the long bones, the process is much the same; from that point the similarity ends. In the long bones there is complete absorption of the cartilaginous pillars to form the large marrow spaces. In the labyrinth capsule, on the other hand, there is a continuous deposition of layers of lamellar bone without previous absorption of the cartilage, making it extremely compact. In the long bones no trace remains of the embryonic structures, but in the labyrinth capsule numerous vestiges of cartilage are found. The most important difference is that in the long bones changes are going on during the whole of life, while in the labyrinth capsule growth is completed by the end of the second year and