306 The Morality of Nature 



purposes as in climbing; while other men of the less gen- 

 erous climates having for some few centuries used boots, 

 and ceased to make prehensile use of toes, have atrophied 

 and modified them to a perceptible degree. They still serve 

 as a flexible terminal of the foot collectively, and still have 

 for that service much effect, but their separate activity in 

 grasping is markedly less. 



The natural weather resisting coverings of the body too, 

 the skin and hair, have lessened in effectiveness of that sort, 

 in proportion as they have been protected, and the skin has 

 gained in sensitiveness. The muscular development of jaws 

 and neck, and the bones to which those muscles are attached, 

 have become smaller and more refined, as their usage be- 

 comes less rough. All these things show a waning of certain 

 powers and structures which however must still be called 

 upward evolution. And in the higher animals, including 

 man, there is of course continuing evolution of constructive 

 effect. The brain size and capacity have been greatly in- 

 creased in those races of men which have intellectual 

 eminence. 



Now if these changes can be visibly made in the historic 

 period, what may be supposed to happen when that period 

 shall have been repeated a hundred times, and what shall we 

 expect of a hundred thousand such periods. That is exactly 

 what we must consider. That is what has occurred, and is 

 now recurring. In the ages we see these small changes 

 adding item by item, and then epoch by epoch, until no 

 doubt whatever is possible that all the present creatures of 

 life have been so cultivated from the simplest forms. It 

 becomes evident that man's period upon earth is a long and 



