III.] LIFE AND DEATH. 1 25 



death with the encystment of the Monoplastides. Now we 

 could, as Gotte rightly remarks, derive the lower forms of 

 Polyplastides from Magosphaera if ' the connection between the 

 cells of the ciliated sphere were retained until encystment, viz. 

 until the reproduction of the single cells had taken place\' 

 After this had been accomplished, Gotte considers that death 

 would consist ' in the complete separation of the cells from one 

 another, accompanied in all probability by their simultaneous 

 change into germ-cells.' The fallacy in this is evident ; if death 

 is represented in one case by the encystment during which 

 single cells change into germ-cells, then this must apply to the 

 other case also, for nothing has changed except the duration of 

 the cell-colony. The nature of encystment cannot be affected 

 by the fact that the cells separate from one another a little 

 earlier or a little later. If it is true that death is represented 

 by encystment among the Monoplastides, then the same con- 

 clusion must also hold for the Polyplastides ; or rather death 

 must be represented in them by the process of rejuvenescence, 

 which Gotte considers to be the essential part of encystment. 

 Gotte ought not to identify death with the dissolution of the 

 cell-colony of which the lowest and highest Polyplastides are 

 alike composed ; but he should seek it in the process of re- 

 juvenescence which takes place within the germ-cells. If 

 it is essential to the nature of reproduction that the cells set 

 apart for that purpose should pass through a process of reju- 

 venescence, which is equivalent to death, then this must be true 

 for the reproductive cells of all organisms. If these conclusions 

 hold good, there is nothing to prevent us from assuming that 

 such a process of rejuvenescence actually occurs in the higher 

 animals. Gotte evidently holds this view, as is plainly shown 

 in the last pages of his essay. He there attempts to bring his 

 views of the death and rejuvenescence of the germ into har- 

 mony with his previously developed idea of the derivation of 

 death among the Polyplastides from the dissolution of the cell- 

 colonies. Gotte still clings to the view which he propounded 

 in describing the development ot Bonibinator, according to 

 which the egg-cell of the higher Metazoa must pass through a 

 process of rejuvenescence representing deatli, before it can 

 become a germ. 



» 1. c, p. 47. 



