CHAPTER IX 



THE TIME OF ORGANIZED BEINGS— 

 THE CHEMICAL CLOCK 



The visual impression obtained by t±ie observer in the moon 

 mentioned in the preceding chapter, gives rise in his mind to 

 an idea of continuity. This continuity which, neglecting the 

 individual, uniformly pursues its course, would be for us the 

 expression of immortality, or the prolongation beyond death 

 of the individual, and through him, of the characteristics which 

 he had himself inherited from his parents. No matter what 

 mechanisms (sexual or asexual reproduction) are brought into 

 play by nature to impart this immortality, we know that it 

 exists; we can control it. Woodruff, Metalnikov and others 

 have shown that, with unicellular animals (infusoria) one could 

 start with a single individual which spontaneously divides 

 itself in two, then in four and so on, and obtain on an average 

 from six to seven hundred generations a year (about 174 

 generations per day). The experiments were followed for 

 several years (seven years by Woodruff and more than twenty- 

 three years by Metalnikov). It is evidently impossible to 

 speak of the absolute immortality of the cell on the basis of 

 experiments having lasted only a few years. But the idea in 

 itself has become commonplace since the works of Pasteur 

 and the failure of all attempts to create living matter from 

 inorganic matter. To-day as formerly we admit that: 'Omnis 

 cellnla a cellula' The important fact from our point of view 

 is relative immortality, that is, with respect to the duration of 

 the mean individual cycle, between two cellular divisions or 

 between two births. In unicellular animals the cells do not 

 die — except accidentally — as each one at a given time divides 

 itself in two and starts off again. In superior organisms, the 

 immortal cells are the sexual cells. All the others grow old 

 and die, following a determined rhythm. But the gametes, 

 or sexual cells, are the origin of every organized being which 



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