THE EVOLUTION OF SEX. 

 20 



protoplasm. The females, on the other hand, live at a profit, are more 

 anabolic, — constructive processes predominating in their life, whence 

 indeed the capacity of bearing offspring. 



No one can dispute that the nutritive, vegetative, or self-regarding 

 processes within the plant or animal are opposed to the reproductive, 

 multiplying, species-regarding processes, as income to expenditure, or 

 as building up to breaking down. But within the ordinary nutritive 

 or vegetative functions of the body, there is necessarily a continuous 

 antithesis between two sets of processes, — constructive and destructive 

 metabolism. The contrast between these two processes is seen through- 

 out Nature, whether in the alternating phases of cell-life, or of activity 

 and repose, or in the great antithesis between growth and reproduc- 

 tion; and it is this same contrast which we recognize as the funda- 

 mental difference between male and female. The proof of this will run 

 through the work, but our fundamental thesis may at once be roughly 

 enunciated in a diagrammatic expression (which in its present form we 

 owe to our friend Mr. W. E. Fothergill): — 



Nutril on. Reproduction. 



•Anabolism. Katabolism Female Male. 



Fig. 11. 



Here the sum-total of the functions are divided into nutritive and 

 reproductive, the former into anabolic and katabolic processes, the 

 latter into male and female activities, — so far with all physiologists, 

 without exception or dispute.* Our special theory lies, however, in 

 suggesting the parallelism of the two sets of processes, — the male 

 reproduction is associated with preponderating katabolism, and the 

 female with relative anabolism. In terms of this thesis, therefore, both 



* The reader whose physiological studies have not been so recent as to 

 familiarize him with that conception of all physiological processes as finding 

 their ultimate expression in the metabolism (anabolism and katabolism) of pro- 

 toplasm, will easily place himself in a position to check our argument (often 

 indeed, we trust to carry our interpretation of sex into still further detail) by 

 starting from the exposition of this doctrine in Dr. Michael Foster's article, 

 " Physiology," in the Encyclopedia Britannica, or with Dr. Burdon Sanderson's 

 Presidential Address to Section D, British Association, 1889. The essential 

 conception will, however, become clearer as we proceed (see pp. 84, 117). 



