ARTIFICIAL PARTHENOGENESIS AND OXIDATIONS LT. 
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 
a3, i? Duration of Oxygen 
ee ee Experiment Consumption 
Exp. I. Normal sea-water............ 75 min. 0.87 mg. 
Hypertonic sea-water (50 c.c. sea- 
water+8 c.c. 23 m NaCl+KCI+ 
RE rere ins oe soe Sax lel 8 ae oS 75 0.86 
Exp. II. Normal sea-water.......... 90 0.60 
Hypertonic sea-water (50 c¢.c. sea- 
water+8¢.c. 23 m NaCl+hKCl+ 
Elo eS ee ee 90 0.52 
Exp. III. Normal sea-water.......... 60 0.55 
Hypertonic sea-water (50 c¢.c. sea- 
water+8 ¢.c. 24 m NaCl+KCI+ 
CYTO) 5) Jane Ric RR ene ara 60 0.59 
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 S. 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 
hypertonic solution does not produce its corrective effect upon 
the egg (after artificial membrane formation) in the absence of 
