DESCRIPTION 
All figures were drawn with the camera lucida with Leitz 7: oil immersion 
objective and No. 5 ocular, except where otherwise stated. All figures from 
sections of inseminated eggs of Platynereis megalops. All sections from eggs 
killed in Meves’ fluid and stained in iron haematoxylin. 
PAB: 
EXPLANATION OF FIGURES 
1. Section of an unfertilized ovocyte. The oil drops are a delicate brown, 
the granular yolk spheres very lightly stained. The cortex is intact. 
2. Ten minutes after laying. The cortex is partially reduced. The head, 
middle-piece, and tail are clearly shown. 
3 to 5. Fifteen minutes after laying. The granules are massed below the 
point of sperm attachment; the perforatorium is still attached to the membrane 
6 to 8. Twenty minutes after laying. 
6. The perforatorium is touching the cytoplasm. The granular mass has 
disappeared. 
7. The perforatorium is in the cytoplasm. 
8. A somewhat tangential section, showing the very beginning of penetration. 
9 to 13. The penetration stages, twenty-five minutes after laying, mesophase 
of the first maturation division. ‘The figures show that there is no constant 
disposition of granules at the point of sperm entry—certainly nothing of the 
nature of a cone, as in Nereis. : 
