THE RAW MATERIALS OF EVOLUTION 125 



smothered, rarely made. A man with an idio- 

 syncrasy, who is snubbed as an impossible person, 

 may be a Moses who might have led us out 

 of bondage ! Captain Fitzroy nearly refused to 

 take Darwin on the Beagle voyage because of 

 his nose ! 



For various reasons biologists take a strong I 

 interest ia the play of animals and of children. 

 Play is no mere safety-valve for overflowing} 

 animal spirits : it is a rehearsal, without responsi- 

 bilities, of some of the essential activities of adult 

 life. But it is more : it affords what the Germans 

 call Ahdnderungsfielraum — ^playground for varia-j 

 tions. The playing organisms are the most! 

 educable. 



The distinction between variations and modifica- 

 tions seems sometimes academic and tiresome, but 

 if we understand it we see it as one of the most 

 practical of questions. Do the innate changes 

 in the natural inheritance furnish the whole raw 

 material of progress, or do the changes in the body 

 due to peculiarities of nurture furnish some ? At 

 present the scientific answer seems to be, that the 

 raw material of organic evolution is due to varia- 

 tions, and in no direct way due to modifications. 

 How closely this touches human hfe ! There is 

 social evolution as well as organic evolution, and 

 social evolution has provided an apparatus whereby 

 the gains of experience may swell the legacy of 

 successive generations, although they do not, from 

 the nature of the case, become part of the germinal 

 inheritance. 



As Lloyd Morgan ^ well says : " The history of 



1 "Mental Factors in Evolution," in "Darwinism and Modern 

 Science" (1909), p. 4i5. 



