CHAPTER X. 



Theory of Sex — its Nature and Origin. 



Having 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 HI., with fertilisation, 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 in- 

 vestigators have, of course, long ago added Blumen bach's 

 " Bildungstrieb " to the list ; nor is it claimed that the 

 generalisation 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 katabolism of protoj)lasra. 



§ 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 nutritive, 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." 



