342 LIFE AND DEATH, 



phytes and the protozoa situated one degree lower in 

 the scale than the infusoria, we must admit the 

 possibility of that perfect and continuous equilibrium 

 which would save them from senile decrepitude. 

 And it is quite understood that this privilege re- 

 mains subordinated to the perfect constancy of the 

 appropriate medium. If the latter changes, the 

 equilibrium is broken, the small insensible per- 

 turbations of nutrition accumulate, vital activity 

 decays, and in sole consequence of the imperfection 

 of the extrinsic conditions or of the medium, the 

 living being finds itself once more dragged down to 

 decay and to death. 



Immortal Elements of the Metazoa. — All the pre- 

 ceding facts and considerations refer to isolated cells, 

 to monocellular beings. But, and this is what makes 

 these truths so interesting, they may be extended to 

 all cells grouped in collectivity — i.e., to all the 

 animals and living beings that we know. In the 

 complicated edifice of the organism, the anatomical 

 elements, at any rate the least differentiated, would 

 have a continual brevet of immortality. Generally 

 speaking, this would be the case for the egg, for the 

 sexual elements, and perhaps, too, for the white 

 globules of the blood, the leucocytes. And, further, 

 around each of these elements must be realized the 

 invariably perfect medium which is the necessary 

 condition. This does not take place. 



Elements in Accidental and Remediable Death. — As 

 for the other elements, they are like the infusoria, 

 but without the resource of conjugation. The 

 ambient medium becomes exhausted and intoxicated 

 around each cell, in consequence of the accidents 

 which happen to the other cells. Each therefore 



