Annulate Lamellae in Sarcoma I Cells

Annulate lamellae have been observed in eggs of marine invertebrates (1, 6, 12, 13, 18), rat spermatids (11, 17), crayfish spermatocytes (15), the amphibian pancreas (17), the adrenal cortex of the fetal rat (14), Sarcoma 37 cells (4), HeLa cells (5), Ehrlich and Yoshida ascites tumor cells (20), m ammary carcinoma cells of the rat (16), and cells of a chicken fibrosarcoma (3). Neither the origin nor the function of annulate lamellae has been established. In the present communication, annulate lamellae are demonstrated in Sarcoma I cells grown in susceptible and resistant strains of mice. A variation in structure of annulate lamellae in a cell from a tumor undergoing homograft rejection is described.