[So-called lamellar structures in non-fertilized rat ovum]

The ultrastructural study of the unfertilized Rat egg ooplasm has shown that the so-called lamellar structures are in fact filaments constituted of proteins and where no ribonucleic acid can be detected. Thus, they do not represent a particular organization of polyribosomes. These filaments could be considered as protein stockage, maybe from membranous origin, ready for use during segmentation. Several figures suggest that endocytotic vesicles and vacuoli constitute the source of the filamentous material.