Chondrogenesis in cultures of endosteum

Abstract

In earlier work on the histogenesis of the fowl skeleton (Strangeways and Fell, 1926; Fell, 1928), it was shown that nodules of small-celled, non-ossifying cartilage developed very readily in cultures of limb-bud mesoderm and that in very rare cases (Fell, 1928) the chondroblasts hypertrophied and ossification occurred. More recently (Fell, 1932) similar nodules of small-celled cartilage were found to develop in cultures of early (6-day) embryonic periosteum. Studitsky (1932), using the method of chorio-allantoic grafting, has obtained chondrogenesis in grafts of later (15-19 day) embryonic periosteum, but he does not specify what type of cartilage developed. In previous experiments (Fell, 1932) cultures in vitro of endosteum from the tibiæ of hatched chicks always produced bone or osteoid tissue but chondrogenesis was not observed. In the course of later investigations, however, some striking examples of the formation of hypertrophic cartilage in endosteal cultures were obtained, and the present communication describes the development of such cartilage, and its subsequent direct transformation into osteoid tissue or bone.