116 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 



The values are practically identical. The eggs treated 

 with the hypertonic solution developed after being put in normal 

 sea-water. 



In a second experiment the unfertilized eggs consumed after 

 membrane formation with butyric acid in normal sea-water 

 . 52 mg. 2 in 65 minutes. The same eggs were then put into 

 hypertonic sea-water (50 c.c. sea-water+8 c.c. 2J m Ringer) 

 and consumed here in 65 minutes 0.54 mg. 2 . The tempera- 

 ture was in both cases 18. These eggs developed after being- 

 transferred to sea-water. 



In another experiment the unfertilized eggs consumed, after 

 the artificial membrane formation with butyric acid, . 83 mg. 

 in 60 minutes in normal sea-water; during the next hour they 

 were put into hypertonic sea-water and consumed in 60 minutes 

 . 74 mg. During the next 60 minutes they were again put into 

 normal sea-water where they consumed 0.70 mg. 2 in 60 

 minutes (at the same temperature). 1 



It is obvious from these experiments that the hypertonic 

 solution does not act by increasing the rate of oxidations. This 

 agrees with the conclusion we reached before, that the mem- 

 brane formation is the real activating agent while the hypertonic 

 solution acts only as a corrective. 



3. Warburg 2 states that if the eggs of S. lividus are fertilized 

 with sperm and afterward put into a hypertonic solution the 

 rate of oxidations is thereby increased 300 per cent. Since 

 Wasteneys and the writer found that the hypertonic solution 

 of the concentration required for artificial parthenogenesis does 

 not raise the oxidations of the eggs of S. purpuratus after 

 artificial membrane formation, we were curious to know whether 

 such a hypertonic solution raises the rate of oxidations in the 

 eggs of S. purpuratus fertilized with sperm. Table XII gives 

 the result. 3 



1 Loeb and Wasteneys, Jour. Biol. Chem., XIV, 469, 1913. 

 Warburg, Zeitschr. f. physiol. Chem., LX, 443, 1909. 

 3 Loeb and Wasteneys, op. cit. 



