50 



INJUEY, RECOVERY, AND DEATH 



that the behavior of frog skin in these solutions resem- 

 bles that of Laminaria. On the other hand, such 

 substances as NaCl and KCl produce in frog skin and 

 in Rhodymenia no rise, but only a fall of resistance, 

 just as in Laminaria. 



Gray (1915) found that a rise in resistance is pro- 



Percent 



]40 



\OCKi 



60- 

 Mrs. 



Fig. 21. — Curves showing the effect of CaClz 0.278 M on the net electrical resistance of 



Laminaria agardhii (upper curve) and of Rhodymenia palmata (lower curve) . The ordinate! 



denote net electrical resistance. Temperature 17 =*= 2° C. Average of six ezperimenta. 



Probable error of the mean less than 3% of the mean. 



duced in echinoderm eggs by La and Ce. Shearer (1919, 

 B) was unable to find such an effect in bacteria. 



It was of especial interest to investigate the effect 

 of the hydrogen ion, which in many respects behaves 

 unlike other monovalent kations. The first experiments 

 were made by adding to sea water a solution of HCl of 

 the same conductivity as the sea water (about 0.119 M). 

 The results are shown in Fig. 22. 



It will be seen that a rise occurred and that in higher 



