314 Dynamic Theory. 



female. If the sacrifice of the tissue undergone by the male in the 

 production of spermatozoa is "katabolic," so it is in the corresponding 

 process of the production of ova by the female. 



The case is the same in the higher grades of life. Amongst the mam- 

 mals the female is the nurse ; and the habit of nursing has caused her 

 to be supplied with a quantity of food for her nursling. That it is for 

 her nursling and not herself is proved by the periodical turgescence, or 

 menstrual hemorrhage which takes place, when in the absence of the 

 nursling she gets rid of it. Then, again, the lacteal secretion, which 

 G-eddes and Thomson point out as an example of the anabolic habit, 

 is absent, except when there is a progeny to profit by it. The extra 

 supply of nourishment supplied to the female for nursing purposes, is 

 drawn through her own food-elaborating economy which is compelled 

 to do that much more work, and the process must, on the whole, so far 

 as the mother is concerned, be katabolic. That this extra supply of 

 nutritive matter to the female is a mere incident of her position and the 

 duty put upon her of nursing the embryo and the young, is proved by 

 the fact that it ceases at the termination of the child-bearing 'period, 

 and by the fact that the milk-giving function is sometimes developed in 

 the male, and in the case of man at least, might by habit become a 

 common masculine function. Amongst the mammals and birds the 

 males are usually the largest, strongest, and most vigorous, but this is 

 due to habits of exertion put upon them by their social and domestic 

 relationships and their position as head and defender of the family. 

 The rule is proved by the occasional exceptions in which the female, by 

 assuming similar relationship, has succeeded to the corresponding pre- 

 dominance in size and vigor. As masculine superiority, seen in birds 

 and mammals, especially among polygamists, is no proof of a sexual 

 anabolism on their part, so the superiority of females, where it occurs so 

 commonly amongst invertebrates and more rarely amongst the verte- 

 brates, is no proof of it on their part. The body is one thing and the 

 essential qualities of sex quite another. 



The essential difference between asexual and sexual reproduction is 

 in the fact that when the asexual cell is divided the two parts are equal, 

 and each half is an epitome, in reduced dimensions, of the original whole, 

 and contains within itself all the conditions necessary to reproduce a 

 copy of the parent cell ; while the first differentiation which makes the 

 two parts unlike, though still equal, necessitates that reunion or splicing 

 which constitutes the essential feature of sexuality. The succeeding 

 differentiations constantly exaggerate this first one, making the apparent 

 distinctions between the moieties which stand in complemental relation- 

 ship to each other more and more pronounced ; constantly eliminating 

 whatever elements of " maleness " may remain in the ovum, and of 

 femaleness that may remain in the spermatozoon. 



