ON THE CONDUCTION OF THE CORTICAL CHANGE AT FERTILIZATION IN THE STARFISH EGG

Abstract

When eggs of the starfish are pinched into two cytoplasmic fragments which lie within the same outermost membrane (the fertilization membrane-to-be), and are inseminated while the two fragments are separate, each fragment receives one sperm. If the fragments completely fuse before insemination, only one sperm enters the fused egg. If the fragments are merely touching, each may receive a sperm. If they are joined by a very narrow fused neck of protoplasm, only one sperm enters.