Protoplasmic papillae of Echinarachnius oocytes

Abstract

Unripe eggs ofEchinarachnius parma, with germinal vesicle intact, in the presence of sperm, give rise to protoplasmic processes protruding from the surface of the oocyte. These processes have been termed “oocyte papulae”. The oocyte papillae may be fine threads, heavy club-shaped structures, or thin, broad films. The papillae are of hyaline protoplasm, amoeboid in movement, and of temporary existence, persisting, on an average, some twenty minutes. The papillae are apparenty functionless structures representing a premature response which, in the ripe ovum, or in the embryo, would produce similar but functional processes. The gel nature of protoplasm is emphasized by the marked rigidity and elasticity of the oocyte papillae.