26 THE EVOLUTION OF SEX. 



gradually perpetuated and perfected a casual advantage. 

 According to the present view, males are stronger, handsomer, 

 or more emotional, simply because they are males, — i.e.^ of 

 more active physiological habit than their mates. In phrase- 

 ology which will presently become more intelligible and 

 concrete, the males live at a loss, are more katabolic^ — dis- 

 ruptive changes tending to preponderate in the sum of changes 

 in their living matter or 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, or 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 throughout 

 nature, whether in the alternating phases of cell life, or of 

 activity and repose, or in the great antithesis between growth 

 and reproduction ; and it is this same contrast which we 

 recognise as the fundamental 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 V/. E. FothergiU) : — 



SUM OF FUNCTIONS. 



Nutrition. Reproduction. 



Anabolism. Katabolism. Female. Male 



Here the sum-total of the functions are divided into 

 nutritive and reproductive, the former into anabolic and 



