1905.] Effects of Alkalies, etc., on Eggs of Echinus. 131 



Fig. 26. — Cell in morula, in sea-water, + 0'0075 M. di-sodium phosphate, showing- 

 shortening of rod chromosomes to dots, and reduction in number. 



Fig. 27. — Two cells in blastula, in sea-water, + 0"005 M. di-sodium phosphate, showing 

 partial shortening and reduction of chromosomes and protrusion of sjjindles, as if 

 polar bodies were being formed. 



Fig. 28. — Egg in two-celled stage in sea-water, -t-0'0015 M. potassium hydrate, showing 

 shortening of dividing chromosomes to dots and reduction in number. 



