336 The Study of Animal Life PART iv 



proved that the definite changes produced on an individual 

 by influences of use, disuse, and surroundings, do not reach 

 the reproductive cells, and cannot, therefore, be transmitted, 

 it is not thereby proved that secondary results or some results 

 of such definite changes may not have some effect on the 

 germ-cells. The conditions are so complex that it seems 

 rash to deny the possibility of such influence. 



Certainly it is no easy task to explain all the adapta- 

 tions to strange surroundings and habits, or the majority of 

 animal instincts, or the progress of men, apart from the 

 theory that some of the results of environmental influence 

 and habitual experience are transmitted. I am certainly 

 unable to reconcile myself to the opinion that the progress 

 of life is due to the action of natural selection on fortuitous, 

 indefinite, spontaneous variations. 



I believe that the conclusion of the whole matter should 

 be an emphatic " not proven " on either side, while the 

 practical corollary is that we should cease to talk so much 

 about possibilities (in regard to which one opinion is often 

 as logically reasonable as another), and betake ourselves 

 with energy to a study of the facts. 



5. Social and Ethical Aspects. All the important 

 biological conclusions have a human interest. 



The fact of organic continuity between germ and germ 

 helps us to realise that the child is virtually as old as the 

 parent, and that the main line of hereditary connection 

 is not so much that between parent and child as "that 

 between the sets of elements out of which the personal 

 parents had been evolved, and the set out of which the 

 personal child was evolved." " The main line," Galton 

 says, " may be rudely likened to the chain of a necklace, 

 and the personalities to pendants attached to the links." 

 To this fact social inertia is largely due, for the organic 

 stability secured by germinal continuity tends to hinder 

 evolution by leaps and bounds either forwards or backwards. 

 There is some resemblance between the formula of heredity 

 and the first law of motion. The practical corollary is 

 respect for a good stock. 



That each parent contributes almost equally to the off- 



