PERENNITY OF COMPLEX INDIVIDUALS. 333 



We must therefore return from them to the elementary 

 being, and we must examine it from the point of view 

 of perennity or of vital decay. Let us then ask the 

 questions that we have already examined with refer- 

 ence to animals high in organization and to man 

 himself. Is the death of the cell an inevitable char- 

 acteristic? Are there any cells, protophytes, protozoa, 

 which are immortal ? 



