Ryder.] [May 16, 



The processes of metabolism, it is true, are carried a stage further in the 

 production of flagellate germs and male elements than in the female, but 

 it is not towards a lower plane of molecular structure, but towards a 

 higher one than in the female germ. It may be said that metabolism is 

 controlled by the nucleoplasm or chromatin, in that the volume of the one 

 increases with the volume of the other as in a growing Amoeba. An in- 

 sufficiency of nucleoplasm would render a cell inert and incapable of 

 coordinating its large cytoplasmic field, as experiment seems to demon- 

 strate. The continuous processes of growth therefore ending in the ex- 

 pulsion of the polar bodies bring about such a stage of cytoplasmic inertia, 

 in which the process of fertilization and the concomitant access of a highly 

 complex and anabolic male element would restore the balance between 

 the cytoplasm and the nucleoplasm. The "katabolic tendency" of the 

 male element is more apparent than real ; it has a greater capacity for 

 katabolic change than the female as measured by the relative volume of 

 its nucleoplasm, but absolutely it has far less because of its small size as 

 compared with the whole ovum. The question of the genesis of sex is 

 not to be disposed of in quite so simple a way as is done by Geddes and 

 Thomson, or in a sentence. These authors have missed the essence of the 

 matter in that they have not noted the essential distinction which exists 

 between the egg and the spermatazoon, nor the transcendant importance 

 of the process of cumulative integration. The cytoplasm preponderates 

 in the one, while the nucleoplasm preponderates in the other. No reason 

 for this has been assigned by these authors. Is not the evolution of a 

 larger amount of nucleoplasm than is contained in the egg, as must hap- 

 pen were it to break up into spermatozoa expressive rather of preponder- 

 ant anabolism than of preponderant katabolism ? Is also the greater 

 mobility of the male element an expression of a specially katabolic ten- 

 dency ? Is not its mobility due to an inherited tendency in part, derived 

 from its most remote flagellate ancestor, and partly to its small size, form, 

 mode of genesis and molecular structure ? 



The contrast between the modes of production of the male and female 

 elements in Ostrea edulis is typical. The difference appears to lie solely 

 in the fact that, in the case of the egg, the whole of the overgrown sper- 

 inatogonium is expelled, but is not a mature ovum until after the expul- 

 sion of the polar bodies ; in the expulsion of the male elements only 

 a part of the spermatogonium is expelled, this process being accompanied 

 beforehand by the elaboration of an excessive amount of chromatin by 

 the mother nucleus of the spermatogonium, this chromatin serving to form, 

 in the main, the nuclei of the multitudes of spermatozoa so set free. In 

 that the chromatin used in the development of spermatozoa is formed at 

 the expense of the cell body of the spermatogonium, there is an almost 

 exact equivalence in the plasma that remains as the cell body of the 

 ovum, so far as the metabolism expended in its production is concerned. 

 The essential difference seems to me to lie not so much in any supposed 

 diatheses which are more or less anabolic as in a difference in the func- 



