INJURY AND EECOVEEY 81 



— (1 -f- 100) ] ^ (1 -r- 100) = 26.68%. During the next 95 

 minutes it showed no change. It was then placed in NaCl 

 for 5 minutes and the resistance fell to 82.8%. It was then 

 replaced in sea water ; a reading taken 10 minutes later 

 showed that it had returned to normal, where it remained 

 for 90 minutes. It was then placed in NaCl for 5 minutes. 

 The resistance fell to 86.42% and returned to normal dur- 

 ing the ensuing 10 minutes in sea water. After 105 



Fig. 33. — Graph showing the fall of net electrical leBistance of hatPinaria agardhii in NaC 



0.52 M (unbroken line) and recovery in sea water (broken line). All readings were made at 



20° C. or corrected to this temperature. The graph represents a single experiment. 



minutes in sea water (during which no change occurred) 

 it was again exposed to NaCl for 5 minutes. The resist- 

 ance fell to 82.8% and returned again to normal during 

 the following 10 minutes in sea water. On the following 

 day its resistance was only 30 ohms below the resistance 

 of the control, which at the beginning of the experiment 

 was 810 ohms. The results are presented in Fig. 33. 



The successful outcome of this experiment led to an 

 attempt to carry on such an experiment for several days 

 in succession, giving the tissue one treatment daily with 

 NaCl. The material was selected with especial care. The 

 fronds were fairly thick, without reproductive organs. 

 The experiment was made at Woods Hole, Mass., in July, 

 at which time such fronds may be easily obtained. The 

 disks cut from these fronds were slightly curved, so that 

 when placed in the apparatus they separated spontan- 



