THE WONDERS OF LIFE 



life, and so can have no adequate idea of its termination 

 — death. 



The inquiry into the nature of organic life which we 

 instituted in the second chapter has shown us that it is, 

 in the ultimate analysis, a chemical process. The 

 " miracle of life " is in essence nothing but the metab- 

 olism of the living matter, or of the plasm. Recent 

 physiologists, especially Max Verwom and Max Kasso- 

 witz, have pointed out, in opposition to modem vitalism, 

 that " life consists in a continuous alternation between 

 the upbuild and the' decay of the highly complicated 

 chemical unities of the protoplasm. And if this concep- 

 tion is admitted, we may rightly say that we know what 

 we mean by death. If death is the cessation of life, we 

 must mean by that the cessation of the alternation 

 between the upbuild and the dissolution of the mole- 

 cules of protoplasm ; and as each of the molecules of pro- 

 toplasm must break up again shortly after its formation, 

 we have in death to deal only with the definite cessation 

 of reconstruction in the destroyed plasma-moletules. 

 Hence a living thing is not finally dead — that is to say, 

 absolutely incompetent to discharge any further vital 

 function — until the whole of its plasma-molecules are 

 destroyed." In the exhaustive justification with which 

 Kassowitz follows up this definition in the fifteenth 

 chapter of his General Biology, the natural causes of 

 physiological death are fully described. 



Among the numerous and contradictory views of 

 recent biologists on the nature of death we find many 

 errors and misunderstandings, due to a lack of clear 

 distinction between the duration of the living matter in 

 general and that of the individual life-form. This is 

 particularly noticeable in the contradictory views which 

 have been elicited by August Weismann's theory (1882) 

 of the immortality of the unicellulars. I have shown in 

 the eleventh chapter of the Riddle that it is untenable. 



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