I 8 CELLULAR 



dyes (and other substances) which is observed in 

 dead or dying cells. 



An advantage of the electrical method is that 

 it gives us time curves of the process of death 

 which can be analyzed mathematically and 

 which enable us to make quantitative predictions 

 regarding the behavior of protoplasm under 

 various conditions. It may also enable us to place 

 upon a quantitative basis such fundamental con- 

 ceptions as normal vitality, injury, recovery, and 

 death, which have hitherto been vaguely de- 

 fined. 



We find, for example, that when the normal 

 electrical resistance has been ascertained it is a 

 simple matter to test material as it comes into 

 the laboratory and to tell whether it is in normal 

 condition or not. If it is not normal we can de- 

 termine just how far it deviates from normality 

 and predict with considerable accuracy how long 

 it will live. 



As an illustration of the method we may con- 

 sider what happens when the marine plant, 

 Laminariay is taken out of its normal environ- 

 ment of sea water and placed in a solution of 



