FERTILIZATION REACTION IN ARBACIA PUNCTULATA. 



273 



concentrations of each of the metallic salts. Readings were 

 made at the end of fifteen minutes, one half hour, and at half- 

 hour intervals thereafter for four and one-half hours. In this 



Table VII6. 



Metallic Superficial Cytolysis 



Salt. Begins. Hours. 



AuCls | 



HgCl. § 



CuCh 1 



ZnCh i| 



LaCls 2 



AlCls 2 



PtCl 4 3 i 



PbCl 2 3 i 



NiCI 2 3§ 



CdCl 2 3 | 



C0CI2 4 



Control in sea-water None in 4^ hours. 



Test of time of cytolysis in membrane-inhibitory concentrations. Eggs, 1 drop 

 to 7.5 c.c. solution. 10 : 45 A.M. 7/26/22. Eggs fresh, 2 9 s. Temp. 22. 5 C. 



experiment, one drop of the uninseminated eggs was placed in 

 7.5 c.c. of the membrane-inhibiting concentration of each of the 

 metallic salts. The container, which was a Syracuse watch- 

 glass was then rotated to insure a thorough mixing of the gametes 

 and the solution. 



Table Vile. 



Effect of membrane-inhibitory concentrations on the sperm. July 18, '22. 

 Sperm suspension made with dry sperm in 7.5 c.c. of the solution. Sperm from 

 two males. 



The experiment in VI Ic was with the membrane-inhibiting 

 concentration of each of the metals and its effect on the sperm. 



