176 L. V. HEILBRUNN. 



NaCl, it does not appear to have the slightest retarding effect 

 on membrane swelling when this is produced by an acid. 



August 28, 1914. Fingerbowl A contained 50 c.c. sea-water 

 plus 3 c.c. TV/io butyric acid. Fingerbowl B contained 49 c.c. 

 sea-water plus 3 c.c. N/io butyric acid plus I c.c. i/io per cent. 

 KCN. When eggs were added to A and B, membrane swelling 

 occurred in both. 



September j, 1914. Stender dish A contained some eggs 

 in 25 c.c. of sea-water. To this was added I c.c. 1/5 per cent. 

 KCN at 10:52 A.M. Then 2 c.c. N/io butyric acid were added 

 29 minutes later (at 11:21). 



Stender dish B contained eggs in 25 c.c. of sea-water, 2 c.c. 

 of N/io butyric acid were added at n :22 A.M. 



In both A and B, membrane swelling occurred and as a result 

 the eggs in both cases stuck to each other and to the bottom 

 of the dish. No difference could be observed between the 

 two sets of eggs, and apparently the KCN has no effect on 

 acid swelling of the membrane. 



KCN is thus capable of inhibiting membrane swelling by 

 NaCl, but it has apparently no effect when the swelling is 

 produced by butyric acid. On the other hand, sea-urchin blood 

 was found to retard or inhibit acid swelling. 



June 22, 1914. A solution of butyric acid in sea-water was 

 prepared by adding to 50 c.c. of sea-water, 2.5 c.c. of N/io 

 butyric acid. Approximately 5 c.c. of the resulting solution 

 were placed in each of two Syracuse watch-crystals (A and B}. 

 To watch-crystal A were added 3 c.c. of filtered sea-urchin blood. 

 (The blood was filtered after it had been allowed to "clot" by 

 standing.) To watch-crystal B, 3 c.c. of sea-water were added. 

 In B, membrane swelling and agglutination occurred, in A very 

 little, if any, membrane swelling occurred, and there was no 

 agglutination. The jelly was dissolved away from the eggs in 

 A, but although the eggs were thus able to come into close con- 

 tact, they would separate again, showing that they were not 

 sticky, and that no membrane swelling had occurred. After 

 a few hours, eggs in B had completely lost their color and ap- 

 peared white to the naked eye, those in A appeared normal. 



July 7, 1914. The above experiment was repeated. In this 

 case an acid solution was made up by adding 5 c.c. N/io butyric 



