130 LIFE AND DEATH. 



In this remarkable arrangement we cannot discern anything 

 except an evident adaptation of the life of the body-cells to repro- 

 ductive purposes, and this adaptation was rendered possible because, 

 after the evacuation of the sexual cells, the body ceased to be of any 

 value for the maintenance of the species. 



But even if we assume, that the death of the Orthonectides is, 

 in Gotte's sense, a consequence of reproduction, inasmuch as, in the 

 two forms of females as well as in the male, the extrusion of a mass 

 of developed germ-cells or embryos deprives the organism of the 

 physiological possibility of living longer, how can we explain the 

 necessity of death as a direct consequence of reproduction in 

 all Polyplastides ? Is the body the soma of the Metazoa so im- 

 perfectly developed, as compared with the reproductive cells, that 

 the extrusion of the latter involves the death of the former ? As a 

 matter of fact in the majority of cases the relations are reversed ; 

 the number of body-cells usually exceeds the germ-cells a hundred- 

 or a thousand-fold, and the body is, as regards nutrition, so com- 

 pletely independent of the reproductive cells, that it need not be 

 in the least disadvantageously affected by their extrusion. And 

 if the Orthonectid-like ancestors of the Metazoa were compelled 

 to give up their insignificant somatic part after the extrusion 

 of their germ-cells, because it could now no longer support itself, 

 does it therefore follow that the somatic cells had for ever lost the 

 power of surviving, even when their phyletic descendants were sur- 

 rounded by more favourable conditions ? Had they to inherit ' the 

 necessity of death ' for all time ? Whence came this great change in 

 the nature of organisms which, before the differentiation of Homo- 

 plastids into Heteroplastids, were endowed with the immortality of 

 unicellular beings ? 



And it must be remembered that it is only an assumption which 

 places the Orthonectides among the lowest Metazoa (Heteroplastids). 

 I do not intend to greatly emphasize this point, but the formation 

 of the Gastrula by embole, and the absence of a mouth and ali- 

 mentary canal, shows that these parasites are extremely degenerate, 

 and the same may be said of almost all endoparasites. The Gas- 

 trula, as an independent organism, was without doubt primitively 

 provided with both mouth and stomach, and the mass of ova 

 filling the female Orthonectid is an adaptation to a parasitic life, 

 which on the one side renders the possession of a stomach a super- 



