284 TEE WHENGE AND THE WHITHER OF MAN 



Can thus natural selection, acting upon fortuitous 

 variations, be the sole guiding process concerned in 

 progress ? Must there not be some combining power 

 to produce the higher individuals which are pre- 

 requisites to the working of natural selection ? 



We are considering the efficiency of natural selec- 

 tion in enhancing useful variations through a series of 

 generations. Let us return to the distinction between 

 productiveness and prospectiveness of social capital. 

 Applied to variations productiveness means immedi- 

 ate advantage, prospectiveness the greater future and 

 permanent returns. Now all persisting variations 

 must, in animals below man, apparently be somewhat 

 productive, else they would not continue, much less 

 increase. Now the immediate return from prospec- 

 tive variations is often smaller than from productive. 

 It looks at first as if productive variations would al- 

 ways be preserved by natural selection, and that pro- 

 spective variations would not long advance. Tet in 

 the muscular system variations valuable largely for 

 their future value are neither few nor unimportant. 

 How can the brain in its infancy develop until it gains 

 supremacy over muscle, or muscle have done the same 

 with digestion ? Now a partial explanation of this is 

 to be found in the correlation of organs. This is 

 therefore a factor of vast importance in progress 

 through evolution. 



Progress in any one line demands correlated changes 

 in many organs. Thus in the advance of annelids to 

 insects the muscular system increases in relative bulk, 

 and absolutely in complexity. But a change or in- 

 crease in the muscle must be accompanied by corre- 

 sponding changes in the motor-nerve fibrils ; and these 



