STUDIES IN ARTIFICIAL PARTHENOGENESIS. IJ5 



no such swelling occurred in A. The effect was not due to the 

 alkaline reaction of KCN, for the swelling of egg membranes in 

 B showed that NaOH had no retarding effect on the process. 

 Likewise the ether present in C appeared to have no inhibiting 

 effect. 



In other experiments KCN behaved similarly. In general 

 it was found advisable to first place the eggs into sea-water 

 which contained KCN and to add the 2.5 M NaCl later. Thus 

 on August 29, 1914, it was found that some membrane swelling 

 occurred when eggs were dropped into hypertonic sea-water to 

 which KCN had already been added, but that this was entirely 

 prevented when the eggs were first exposed to the KCN solution 

 in sea-water, the 2.5 M NaCl being added later. 



August 2Q, 1914. Fingerbowls A, C, D, were used. Into 

 A were placed 50 c.c. sea-water plus 8 drops of egg suspension, 

 and to this were added 8 c.c. of 2.5 M NaCl. Fingerbowl 

 C contained 50 c.c. sea-water plus i c.c. 1/5 per cent. KCN, 

 to this were added at 10:30^ A.M. 8 c.c. 2.5 M NaCl, and at 

 10:31 A.M. 8 drops of egg suspension were dropped into the 

 cyanide containing "NaCl hypertonic sea-water." Fingerbowl 

 D contained 49 c.c. of sea-water plus i c.c. 1/5 per cent. KCN. 

 Several drops of egg suspension were added to this solution 

 of cyanide in sea-water, at 10:40 A.M. At 11:28 A.M. (48 

 minutes later), 8 c.c. of 2.5 M NaCl were added to D. 



On microscopical examination, it was found that pronounced 

 membrane swelling had taken place in A (in the absence of 

 KCN), swelling also occurred in C, but did not appear to be 

 pronounced as that occurring in A. No membrane swelling 

 at all could be observed in D, in which the eggs had been treated 

 first with KCN before the concentrated NaCl solution had been 

 added. 



The above experiment indicates that the action of KCN in 

 inhibiting membrane swelling produced by NaCl, is not the 

 result of a reaction between the cyanide and the salt, but is 

 due to an effect of the cyanide on the membrane. For if only 

 a reaction between salt and cyanide was involved, there could 

 be no advantage in first subjecting the eggs to the action of the 

 cyanide alone. 



Although KCN inhibits the membrane swelling effect of 



