Artificial Pabthenogenesis and Oxidations 117 



These and other similar experiments show that the rate of 

 oxidations in the fertilized eggs of Strongylocentrotus is not 

 altered if the eggs are put into a hypertonic solution of that 

 concentration and during that period of time which is required 

 in the method of artificial parthenogenesis. Only if the ferti- 

 lized eggs remain a much longer period, 90 minutes or longer, 

 in the hypertonic sea-water is the rate of oxidation altered — 

 however, not increased but diminished. 



TABLE XII 



Fertilized Eggs in 



Duration of 

 Experiment 



Oxygen 

 Consumption 



Exp. I. Normal sea-water 



Hypertonic sear water (50 c.c. sea- 

 water+8 c.c. 2i m NaCl+KCl+ 



CaCy 



Exp. II. Normal sea-water 



Hypertonic sea- water (50 c.c. sea- 

 water+8c.c. 2i m NaCl+KCl-H 



CaCy 



Exp. III. Normal sea-water 



Hypertonic sea-water (50 c.c. sea- 

 water-|-8c.c. 2i m NaCl-t-KCl+ 

 CaCy 



75 min. 



75 

 90 



90 

 60 



60 



0.87 mg. 



0.86 

 0.60 



0.52 

 0.55 



0.69 



It may also be stated that Wasteneys and I tried the effect 

 of hypertonic solutions of various concentrations upon the 

 fertilized eggs of S. purpuratus. The result was always the 

 same: The hypertonic solution did not increase the rate of 

 oxidations in the fertilized egg of jS. purpuratus, no matter 

 how high the concentration was raised, as Table XIII shows. 

 Temperature 18° C. 



It is obvious that the increase in the concentration, even 

 beyond that used in the experiments on artificial partheno- 

 genesis, does not increase the rate of oxidations in the fertilized 

 eggs of S. purpuratus. 



4. This result creates an apparent difficulty, namely, why the 

 h3T)ertonic solution does not produce its corrective effect upon 

 the egg (after artificial membrane formation) in the absence of 



