82 



INJUEY, RECOVERY, AND DEATH 



eously, thus allowing the running sea water in which they 

 were kept to circulate freely between them. Care was 

 taken to keep them only about two-thirds submerged, so 

 that they had free access to air, but ran no risk of 

 drying up. The tissue in sea water had a net resistance 

 of 780 ohms at 20 C. As the temperature of the 



DAY 



10 



n 



12 



13 



14 



IS. 



IS 30 



FIG. 34. Graph showing loss of "net electrical resistance of Laminaria agardhii in NaCl 

 0.52 M (unbroken lines) and recovery in sea water (broken lines) on 15 successive days. All 

 readings were made at 20 C. or corrected to this temperature. Each graph represents a 



single experiment. 



sea water varied but slightly from this during the experi- 

 ment, all readings were taken at 20 C. On being 

 placed in NaCl 0.52 M, the resistance fell in 5 minutes to 

 83.3% ; the tissue was then placed in sea water, and a 

 reading taken 10 minutes later showed that it had risen 

 again to the normal. The tissue was then placed in run- 

 ning sea water, with the precautions mentioned above. 

 At the end of 22 hours the resistance was 780 ohms. An 

 exposure of 5 minutes to NaCl resulted in a drop to 87.2%, 

 with complete recovery within 10 minutes. The same 

 treatment was given once each day for 15 days. On the 

 tenth day the resistance began to fall off, but as this 



