18 Mary Blount. 



Summary of the Facts Illustrated by the Charts. 



1. During the maturation stage, the supernumerary sperm nuclei 

 migrate from the blastodisc into the periblast. 



2. The supernumerary sperm nuclei multiply by division in the 

 periblast and migrate peripherally in the marginal periblast. In sub- 



Chart VII. 



germinal positions they arc found as far centrally as the margins 

 of the nucleus of Pander. 



3. As the supernumerary sperm nuclei increase in number, the 

 cells of the primary cleavage are definitely separated from the region 

 of the sperm nuclei by cleavage planes that limit the marginal 

 cells peripherally and ventrally. 



