BIOLOGY IN ITS WIDER ASPECTS 1247 



biologists at present would emphatically refuse the alternative. With- 

 out foreclosing the question, one must say that the evidence of the 

 transmission of bodily modifications even in a slight representative 

 degree is very far from being convincing, though there are some 

 experimental data pointing in the direction of that conclusion. But 

 if modifications of a beneficial sort are not hereditarily entailed, it is 

 plainly our duty to try to re-impress them on each successive 

 generation. That is the practical corollary. If modifications which 

 are to the good are not hereditarily handed on as such or in any 

 representative degree, then surely we should seek to induce similar 

 modifications on each successive generation; and if that is done it 

 may be that these re-impressed modifications will act as a screen, a 

 life-saving protective screen, until a germinal variation in the same 

 direction has time to emerge and grip. 



The commonsense person, for whom we have' a great respect, 

 often says: "But do you really mean to say that the individual 

 experience is of no account in evolution ? " And our biological answer 

 would be: "Of no account apparently as regards the handing on 

 of any specific individually-acquired gain or loss, but of very great 

 account in this way, that the individual experience is the time 

 during which inborn germinal variations can be tested and put to 

 the proof, held to or rejected." Individual experience is the time for 

 the sifting and trying and testing of individual variations, some of 

 which are certainly heritable. 



We should not allow ourselves to become tired of the "nature and 

 nurture" controversy, but its utility is to a large extent blurred by 

 a confusion of thought. Nature and nurture are the two components 

 determining the development of any character. To pit one against 

 the other is like asking whether the waves dashing in on a particular 

 part of the coast are due to the tide or to the wind; they are, of 

 course, due to both; and so it is with all our features and characters, 

 of mind and of body. All are resultants of two components, both of 

 which are necessary. Therefore it becomes a rather theoretical 

 question as to the relative importance of the two components — 

 not whether one or other should be regarded as essential. We must 

 admit that there are some callous natures, very self-contained 

 people, very unsusceptible, who are not readily amenable to nurture, 

 as was suggested when in Shakespeare's Tempest Prospero said of 

 Caliban: "A devil, a born devil on whose nature nurture will never 

 stick." But that is not the way with the majority: nurture does 

 stick, and it begins nine months before birth, and it includes not only 

 the wind, the rain and the sun and all that sort of thing, it includes 

 the influences of the social heritage which is continued from genera- 

 tion to generation outside the organism altogether. 



Fourthly, the biologist has much to say to the sociologist about 



