82 



INJUEY, RECOVERY, AND DEATH 



eously, thus allowing the ninning sea water in whicli 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 



100H( 



f-- 



r- 



15 30 

 MIH. 



r— 



r 



\ 



n 



^-- ^ >- 



5 



r - 



Fig. 34. — Grapli 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 



