The synthesis of cytoskeletal and membrane polypeptides of the chick lens epithelium, superficial cortical fiber cells and deep cortical fiber cells was studied in the organ-cultured lens. The synthetic activity of the cytoskeletal polypeptides was restricted to the epithelium and superficial cortical fiber cells while membrane polypeptides were synthesized by deep cortical fiber cells as well. None of the polypeptides was observed to be synthesized by the lens nuclear fiber cells.