Ultrastructural aspects of cartilage and membrane bone differentiation from common germinal cells

Abstract

The ultrastructural changes associated with the differentiation of adventitious cartilage and of bone from common germinal cells on the quadratojugal of the embryo chick have been described. The point of divergence of the two cell lines from the common germinal cells has been described and the possible point of action of the morphogenetic switch from osteogenesis to chondrogenesis has been discussed.