106 HUMAN LONGEVITY. 



material of generation, growth, and duration of existence ; 

 that death, while it destroys and dissolves individual forms 

 or lives, does not annihilate these molecules, which pass into 

 other forms, giving and maintaining life as before, and being 

 always the same in total quantity on the globe. This is one 

 of the many fruitless hypotheses common to every age ; easy 

 to construct difficult absolutely to refute or deny impossi- 

 ble to prove. The molecules organiques vivantes of Buffon, 

 like the plastic nature of Cudworth, are an effort to shelter 

 penury of knowledge under the garb of scientific language. 

 Though the higher genius of Leibnitz gave somewhat more 

 of philosophy to his monads, yet essentially the attempt and 

 the failure are the same. Life may be defined, more or less 

 justly, through its functions. In its elements, no reason or 

 hypothesis can reach it. 



M. Flourens, however, while professing admiration of Buf- 

 fon's genius, and acquiescence in the hypothesis as to the 

 equal and constant quantity of life on the globe, places this 

 doctrine on a basis of his own, which we may briefly give in 

 his own words : 



Je n'etudie la vie, ni dans les molecules organiques, ni dans les 

 monades. J'etudie la vie dans les etres vivants ; et je trouve deux 

 choses : la premiere que le nombre des especes va toujours en di- 

 minuant, depuis qu'il y a des animaux sur le globe ; et la seconde 

 que le nombre des individus, dans certaines especes, va toujours 

 au contraire en croissant ; de sorte que, a tout prendre, et tout bien 

 compte, le total de la quantite de vie, j'entends le total de la quan- 

 tite des etres vivants, reste toujours en effet a peu pres le meme. 



No evidence for this doctrine is known to us, and assuredly 

 none is furnished by our author to justify its enunciation 

 as a special discovery. It is very true, as M. Flourens states, 

 that various species of animals some of them, as attested by 

 their bones, of gigantic size have become extinct during 

 what may be called the existing epoch in the history of the 



