Ryder.] -"O [May 16, 



extensive possibilities for variation. This must be true upon the simple 

 ground of the theory of permutations, since every cell added to the aggre- 

 gate of a segmenting germ must increase its capacity to vary. This gives 

 not simply a capacity to vary as if variation were fortuitous, but as a con- 

 sequence a capacity of adaptation which is proportionately and demon- 

 strably greater during their earlier stages, a circumstance again in con- 

 formity with the fact that all living metazoan types have diverged directly 

 from the ovum, as is proved by their ontogeny. 



The reproductive cells, as stated in a previous paper by the writer,* are 

 functionless, so far as being of any service to the parent body producing 

 them is concerned. The only function they have in relation to the parent 

 body, is to lead a pseudo-parasitic existence at the expense of the surplus 

 nutriment elaborated by the parent organism ; but these pseudo-parasitic 

 generative cells are themselves the products of the continuation of the 

 processes of cellular growth and fission of the parent plasma. 



Being functionless, the reproductive cells of both sexes also tend to 

 revert to the most primitive form of reproduction, namely, to break down 

 into spores, as illustrated by the bodily fragmentation of the majority of 

 lower forms into spores, or the multiplication of the nuclei of some of 

 these forms at the expense of their cytoplasm. 



In the male this reversion and breaking down into spores is most com- 

 plete in the evolution of a spermatogonium, in the female it is incomplete 

 in that the reproductive cells are in some way prevented from breaking 

 down either by excess of nutriment or proximity to nutriment under en- 

 closed or encysted conditions, which tends to be overcome at about the 

 time the eggs are set free or after that time, as expressed in the expulsion 

 of the polar bodies. The female individual may therefore be regarded in 

 the light of a male organism in which the excessive tendency to sporu- 

 lation has been repressed or retarded. The female state of all higher 

 forms may be regarded as. a suppressed or retarded male condition. 



This repression of the male condition within the parent body leads how- 

 ever to a process of cumulative growth in the ovary or female gonad 

 which expresses itself as the continued increase of the volume of the sper- 

 matogonium, leading to the evolution of a large amount of cytoplasm. 

 After detachment of the hypertrophied spermatogonium, as an ovum, the 

 source of supply in the form of nutriment is cut off, and whatever karyo- 

 kinesis now goes on must proceed at the cost of a small amount of nucle- 

 oplasm, which soon exhausts itself so far as any exhibition of the energy 

 of growth is concerned in the production of the polar bodies. After the 

 expulsion of the polar bodies the egg is probably able merely to so adjust 

 its internal forces so as to prevent the ovum from disintegrating. 



In this condition the egg is incapable of further growth and in that the 

 spermatic body from a fully developed spermatogonium, developed in the 

 male is alone capable of reinforcing the exhausted female nucleus, so as 

 to let loose the potential energy, for the time being, stably locked up in 



" Origin and Meauing of Sex," Amcr. Nat., 1SS9, pp. 501-50S. 



