DEATH 273 



importance. Weismann defines death as "an arrest 

 of life, from which no lengthened revival, either of 

 the whole or any of its parts, can take place ; or to 

 put it concisely, as a definite arrest of hfe." " The 

 real proof of death," according to Weismann, "is 

 that the organised substance which previously gave 

 rise to the phenomena of life, for ever ceases to 

 originate such phenomena." He adds to this the 

 corollary that death involves the presence of some- 

 thing dead i.e., a corpse. Weismann next challenges 

 the statement that death is a necessity, inseparable 

 from the idea or existence of life. He calls atten- 

 tion to the conditions which obtain among animals 

 such as Protozoa, in which reproduction is normally 

 effected by fission ; and points out that in the life- 

 history of such animals natural death does not occur. 

 An Amoeba for example reproduces by simply 

 dividing into two. In such an act of fission the 

 parent generation disappears, but nothing has died. 

 If the original Amoeba be called Tom, and the 

 products of fission Dick and Harry, the upshot of 

 the process may be expressed by saying that Tom 

 has disappeared without having died, while Dick 

 and Harry have come into existence without having 

 been born. Nothing has died, there is no corpse 

 to bury, and our ordinary ideas with regard to 

 individuality and identity fail altogether to afford 

 answer to the question Where is Tom at the end 

 of the process ? 



Hence arises the idea of the immortality of the 

 Protozoa. An Amoeba or other Protozoon repro- 

 ducing by simple fission can indeed be killed, as 



s 



