142 Papers from the Marine Biological Laboratory at Tortugas. 



The actual times vary somewhat in different experiments, but the 

 above is typical. The results of interest in the above table may be sum- 

 marized as follows: 



The weak alkalies (first seven) enter almost instantly, yet contractions 

 and conduction do not cease till some time ajter the color change occurs. 



The strong alkalies (last four) do not enter until long after cofitraction 

 and conduction have ceased. 



In ammonia and trimethylamine the muscles regularly lose their power 

 of contraction before the nerves. In the remaining alkalies the nerves 

 cease to function before the muscles as direct stimulation shows. The 

 phenomenon is more marked with the inorganic hydroxides. Thus far these 

 alkalies are the only substances known which affect the nerves first and the 

 muscles afterwards. 



Recovery of both contraction and conduction will take place if the 

 tissue is removed to sea-water soon after stoppage of contraction or con- 

 duction occurs. Occasional exceptions to this rule have been recorded in 

 which the nerve-tissue has been so injured in one spot that the impulse was 

 unable to pass. The red color returns only in the tissue exposed to the 

 weak alkalies. 



Recovery from the effects of the strong alkalies never occurs if the 

 tissue is allowed to remain in the solution long enough for the color change 

 to take place, nor does the red color return on transfer to sea-water. 



Ammonia and trimethylamine are less toxic than the remaining amines. 

 The strong alkalies take an intermediate position between the two groups 

 of weak alkalies as regards toxicity for Cassiopea muscle. 



That the resistance to the entrance of neutral red is a property of the 

 living cell may be shown by treating the Cassiopea strips with chloroform- 

 saturated sea-water. The cells are killed and the red-stained granules are 

 cast out in a slime from which the neutral red dye slowly diffuses. If such 

 a strip is placed in N/250 NaOH, the slime is turned yellow in less than two 

 minutes, i. e., just as rapidly as in N/250 NH4OH. To a certain extent the 

 slime prevents free access of NaOH to the tissue. When stripped off with a 

 camel's-hair brush, the underlying tissue, still pinkish in color, is rapidly 

 turned yellow by the alkali. The slime forms most rapidly in the strong 

 alkalies, much less rapidly in the stronger amines, and very slowly in 

 NH4OH and trimethylamine. 



In the following experiments on tissues other than those of Cassiopea 

 and on eggs, the effect of NaOH has always been compared with that of 

 NH4OH, for two reasons: (i) My general experience indicates that NH4OH 

 may be taken as a representative of the weak alkalies and NaOH as a repre- 

 sentative of the strong. (2) Since NaOH always affects the cell before it 

 enters, we might consider the visible alteration in function a more delicate 

 test for the presence of the OH ion within the cell than the neutral red 

 indicator. The control experiment with NH4OH shows that this is not the 

 case. The color change always begins and in many cases is complete before 



