156 THEORY OF INJURY AND RECOVERY 



with certain assumptions we have formulated equations by means 

 of which we can predict the behavior of the tissue. If the predictions 

 are fairly accurate it is natural to infer that the assumptions are in 

 accordance with the facts. It is evident from an examination of the 

 figures that the equations enable us to predict with considerable ac- 

 curacy the behavior of tissues in solutions of NaCl and CaCl2, as well 

 as the recovery curves after any length of exposure to either of these 

 solutions. But we must not lose sight of the fact that the predictive 

 value of the equations does not depend on the validity of these assump- 

 tions and would in no way be impaired if they were to be given up. 

 The equations have a permanent value which is independent of 

 assumptions. 



SUMMARY. 



1. Laminaria exposed for a short period to 0.52 m NaCl loses a 

 part of its electrical resistance but recovers it completely when re- 

 placed in sea water. When the period is lengthened recovery is incom- 

 plete. If the exposure is sufficiently prolonged no recovery occurs. 

 (After exposure to 0.278 m CaCU the resistance falls when the tissue 

 is replaced in sea water.) 



2. Equations are developed which enable us to predict the resist- 

 ance of the tissue during exposure to NaCl or CaCl2 as well as 

 the recovery curves after any length of exposure to either of these 

 solutions. 



