126 THE EVOLUTION OF SEX. 



protoplasmic explosives, which may remain long inert, but on the presence 

 of the required stimulus are able to start again into extraordinary activity. 



§ 3. The P)vblem of the Origin of Sex. — We must now 

 return once more to the standpoint of the empirical naturahst, 

 and set out towards the interpretation of sex from a different 

 side, that of its origin. 



It has often been raised as a reproach against the now 

 fortunately dominant school of evolutionist naturalists, that 

 they could give no account of the origin of sex. Some people, 

 like children, wish everything at once. Yet it must be admitted 

 that there has been a lack of any sure and certain voice on this 

 question. Apart from the simple fact that evolutionist biology 

 is still young, there are three reasons for the comparative 

 silence in regard to the origin of sex. 



(i.) The first of these is the still curiousiy prevalent opinion, 

 that when you have explained the utility or advantage of a 

 fact, you have accounted for the fact, — an opinion which the 

 theory of natural selection has done more to foster than to 

 rebuff. Darwin was, indeed, himself characteristically silent in 

 regard to the origin of sex, as well as of many other " big lifts " 

 in the organic series. j\Iany, however, have from time to time 

 pointed out that the existence of male and female was a good 

 thing. Thus AVeismann finds in sexual reproduction the chief, 

 if not the sole source of progressive change. Be that as it 

 may at present, it is evident that a certain pre-occupation 

 with the ulterior benefits of the existence of male and female, 

 may somewhat obscure the question of how male and female 

 have in reality come to be. 



(2.) A second reason for the comparative silence, may be 

 found in the fact that the problem remains insoluble until it is 

 analysed into its component problems. The question of the 

 origin of sex to a mind unprepared for the consideration of 

 such a problem, suggests quite a number of difficulties, — ^Vhat 

 is the import and origin of sexual reproduction (the setting 

 apart of special cells) ? what is the meaning and beginning of 

 fertilisation (the interdependence and union of sex-cells) ? what 

 is the reason of the individual, male or female, sex in any 

 one case (the determination of sex)? and lastly, what is the 

 nature and origin of the difference between male and female ? — 

 the question at present under discussion. For purposes of 

 analysis, those questions must be kept distinct, though in the 

 final synthesis they are all answerable in a sentence. 



