548 EDMUND NEWTON HARVEY 



ing. The following experiment in which cane sugar is added to 

 the sea water shows that in the presence of chloroform the alkali 

 may enter the eggs before sweUing of the egg has begun. Sugar 

 prevents rapid pushing out of the artificial fertilization membrane 

 which is relatively impermeable to it. 



A. 10 cc. (50 cc. sea water + 10 cc. 2 m cane sugar) + 0.15 

 cc. y'ty NaOH saturated wdth cholorform. 



Neutral red stained eggs are turned yellow in 3-4 minutes. 

 After about 5 minutes swelling is noticeable. If an acid is added 

 the eggs are turned pink again. 



B. Control (10 cc. (50 cc. sea water + 10 cc. 2 m cane sugar) 

 + 0.15 cc. T^o NaOH. 



Red stained eggs remain red for over three hours, in the mean- 

 time undergoing irregular division and fragmentation. Even 

 very small fragmented spheres retain their red granules intact, 

 providing their surface is likewise intact. 



Just as in Paramoecium, observation of the manner in which 

 the color change occurs points to the view that the alkah only 

 enters after it has destroyed the surface. In immature Penta- 

 ceros eggs the red staining granules are present at the periphery 

 separated from the alkaline solution only bj^ the surface film 

 of the egg. Yet they remain red for 15 minutes in .^o NaOH in 

 0.6 n NaCl. Once the NaOH begins to enter the color change 

 is very rapid and the egg swells simultaneously. 



The same is true of Toxo-.)neustes where the red granules are 

 uniformly distributed. There is never a gradual entrance of 

 alkali from the moment the eggs are placed in the alkaline solu- 

 tion but after a certain interval the NaOH passes the surface and 

 then it may be seen to move rapidly within the egg. 



Toxopneustes eggs even undergo irreguiar division in hyperal- 

 kaline sea water (100 cc. sea water + 1.3 cc. ^, NaOH) without 

 the entrance of enough alkali to change the red to yellow. I 

 have not experimented with NH4OH but it is probable, judging 

 from my Paramoecium experiments, that this alkali would pass 

 into the eggs freely and induce the color change before division, 

 c.ytolysis, or any injury to the egg takes place. If such were the 

 case it would show that the action of NaOH as a parthenogenetic 



