Intranuclear Crystal within the Phagocytes of the Ovary of Arbacia Punctulata

The occurrence of in t ranuclear protein crystalloids in "amoebocytes" of sea urchins, was described in the last century by List (reference 13; cf. references 4 and 11 cited by List). Dur ing the course of an electron microscope study of the developmental processes of Arbacia punctulata oocytes, the author ' s a t tent ion was drawn to the presence of crystalloid bodies within the nuclei of the same type of cells in the ovar ian tissues. The present paper describes the crystalline s tructure and the cytochemical properties of these bodies.