THEORY OF SEX— ITS NATURE AND ORIGIN. II9 



i. The first of these is the still curiously prevalent opinion, that 

 when you have explained the ulility 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. Many, however, 

 have from time to time pointed out that the existence of male and 

 female was a good thing. Thus Weismann 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 preoccupation 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 analyzed 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 : What is the import and origin of sexual repro- 

 duction (the setting apart of special cells) ? What is the meaning and 

 beginning of fertilization (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. 



3. A third reason why the problem of the origin of male and 

 female has been so much shirked, why naturalists have beaten so much 

 about the bush in seeking to solve it, is that in ordinary life, for 

 various reasons, mainly false, it is customary to mark off the repro- 

 ductive and sexual functions as facts altogether per se. Modesty 

 defeats itself in pruriency, and good taste runs to the extreme of 

 putting a premium upon ignorance. Now this reflects itself in biology. 

 Reproduction and sex have been fenced off as facts by themselves ; 

 they have been disassociated from the general physiology of the 

 individual and the species. Hence the origin of sex has been involved 

 in special mystery and difficulty, because it has not been recognized 

 that the variation which first gave rise to the difference been male and 

 female, must have been a variation only accenting in degree what 

 might be traced universally. 



IV. Nature of Sex as seen in its Origin among Plants. 

 — In tracing the origin of sex, we would wish to guard against any 

 impression of having consciously or unconsciously arranged our facts 



