III.] LIFE AND DEATH. 1 45 



arrangement — the formation of reproductive cells at one time 

 only, and their sudden extrusion, — presupposes the mortality of 

 the somatic cells, and is an adaptation to it, just as this mortality 

 itself must be regarded as an adaptation to the simultaneous 

 ripening and sudden extrusion of the generative cells. In 

 short, there is no alternative to the supposition stated above, 

 viz. that the mortality of the somatic cells arose with the 

 differentiation of the originally homogeneous cells of the Poly- 

 plastids into the dissimilar cells of the Heteroplastids. And 

 this is the first beginning of natural death. 



Probably at first the somatic cells were not more numerous 

 than the reproductive cells, and while this was the case the 

 phenomenon of death was inconspicuous, for that which died 

 was very small. But as the somatic cells relatively increased, 

 the body became of more importance as compared with the 

 reproductive cells, until death seems to affect the whole indi- 

 vidual, as in the higher animals, from which our ideas upon 

 the subject are derived. In reality, however, only one part 

 succumbs to natural death, but it is a part which in size far 

 surpasses that which remains and is immortal, — the reproductive 

 cells. 



Gotte combats the statement that the idea of death neces- 

 sarily implies the existence of a corpse. Hence he maintains 

 that the cellular sac which is left after the extrusion of the 

 reproductive cells among the Orthonectides, and which ulti- 

 mately dies, is not a corpse; 'for it does not represent the 

 whole organism, any more than the isolated ectoderm of any 

 other Heteroplastid ' (1. c, p. 48). But it is only a popular 

 notion that a corpse must represent the entire organism. In 

 cases of violent death this idea is correct, because then the 

 reproductive cells are also killed. But as soon as we recognise 

 that the reproductive cells on the one side, 'and the somatic 

 cells on the other, form respectively the immortal and mortal 

 parts of the Metazoan organism, then we must acknowledge 

 that only the latter,— that is, the soma without the reproductive 

 cells,— suffers natural death. The fact that all the reproductive 

 cells have not left the body (as sometimes happens) before 

 natural death takes place, does not affect this conception. 

 Among insects, for instance, it may happen that natural death 

 occurs before all the reproductive cells have matured, and these 



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