PLATE II. 



FJG. 15. 



Stages iu the fertilization of Phijsa foutinalis. (After Kostanecki and Wier/ejski.) 



FIG. 12. Mother star stage passing into metakinesis for the formation of tin- first 

 polar body. The spermatozoon is enclosed in the egg in tuto. 



\'K,. 13. Formation of first polar body; centrosome. divided. 



Ki<;. 11. First polar body formed. Monaster stage i'or the formation of the second 

 polar body. Sperm radiation is separated from the sperm nucleus. 



!!<;. 1."). Formation of the second polar body. Sperm radiation with two centrosomes 

 near the vesicular sperm nucleus. 



