| Abstract: | The fine structure of the developing gizzard of the chick embryo has been studied to define the sequence of events in cytodifferentiation of the epithelium and to look for morphological evidence of epithelio-mesenchymal interaction. During the fourth day of incubation epithelial cells begin to form mucous secretory granules, later massive glycogen deposits appear, and finally by day 8 numerous cell processes have formed. Tissue was prepared by a number of methods to stain material associated with cell surfaces. At the time induction is presumbably occurring such stainable material is abundant. Epithelial and mesenchymal tissue components when cultured transfilter show no inductive effects and stainable cell surface material is greatly reduced near the epithelium. |
