THEORY OF SEX— ITS NATURE AND ORIGIN. m 



CHAPTER X. 



THEORY OF SEX — ITS NATURE AND ORIGIN. 



ttaving got so far in our analysis, and before passing to the study 

 of the processes of reproduction, we must add up the results in a 

 general theory of the nature and origin of sex. After this has been 

 done, we shall be in a better position to deal, in Book III., with fer- 

 tilization, parthenogenesis, and the like. The number of speculations 

 as to the nature of sex has been well-nigh doubled since Drelincourt, 

 in the last century, brought together two hundred and sixty-two 

 "groundless hypotheses," and since Blumenbach quaintly remarked 

 that nothing was more certain than that Drelincourt' s own theory 

 formed the two hundred and sixty-third. Subsequent investigators 

 have, of course, long ago added Blumenbach' s " Bildungstrieb " to 

 the list; nor is it claimed that the generalization we have in our 

 turn offered has yet received "final form," if that phrase indeed be 

 ever permissible in an evolving science, except when applied to what 

 is altogether extinct. This much, however, is distinctly maintained, 

 that future developments of the theory of sex can only differ in degree, 

 not in kind, from that here suggested, inasmuch as the present theory 

 is, for the first time, an expression of the facts in terms which are 

 agreed to be fundamental in biology, those of the anabolism and kata- 

 bolism of protoplasm. 



I. Suggested Theories. — According to Rolph, — a fresh and 

 ingenious thinker, removed before attaining his mature strength, — 

 ' ' the less nutritive, and therefore smaller, hungrier, and more mobile 

 organism [cells, he is speaking of] we call the male; the more nutri- 

 tive and usually more quiescent organism is the female." He goes 

 on vividly to suggest why ' ' the small starving male-cell seeks out the 

 large well-nourished female-cell for the purposes of conjugation, to 

 which the latter, the larger and better nourished it is, has on its own 

 motive less inclination." 



Minot, in his "theory of genoblasts," or sexual elements, ventures 

 little further than regarding male and female as derivatives of primi- 

 tive hermaphroditism in two opposite directions. "As evolution con- 

 tinued, hermaphroditism was replaced by a new differentiation, in 

 consequence of which the individuals of a species were — some 

 capable of producing ova only, others of producing spermatozoa only. 

 Individuals of the former kind we call females, of the latter males, anp 

 they are said to have sex." "At present all we can say is, we do 



