February 24, 192 1] 



NATURE 



829 



are handed on unchanged "down the germ-tract"; 

 that the sixth digit was a mutation, due to some 

 change in the genes in the chromosomes, and there- 

 fore gametogenic ; and that the scar was due to an 

 injury which resulted in regenerative processes produc- 

 ing new tissue. Sir Bryan Donkin states that the scar 

 is an "acquired difference," but in terms of the 

 germ-plasm the hand and the scar indicate no change. 

 What, then, is the objection to terming the scar an 

 "acquired character"? Every biologist would agree 

 that it does not indicate a change in the chromo- 

 somes. Its possible subsequent ettect on heredity is 

 expressly excluded from the discussion. 



Yet Sir Bryan Donkin insists that the division of 

 human characters into two groups, "innate" or 

 "acquired," "constitutional" or "lenvironmental," is 

 a cause of much confusion — apparently because, as 

 Sir Archdall Reid insists, "a vague terminology has 

 caused neglect of the evolution of the power of 

 developing in response to functional activity." But, 

 so far as I know, that writer has produced no evi- 

 dence of such an evolution, no evidence that func- 

 tional activity has more effect in the higher animals 

 than in the lower. It is difficult to think of cases of 

 different functional activity among individuals in 

 lower animals, but if we take conditions such as 

 quantity and quality of food, we know that the 

 difference between worker bees and queen bees is 

 entirely due to this difference of "nurture" — in fact, 

 is an "acquired character." Probably Sir Archdall 

 Reid would consider insects as lower than man, 

 though biologists would not admit that he was right. 

 Sir Bryan Donkin writes that like exactly begets like 

 when parent and child develop under like conditions ; 

 if we say, then, that the differences due to unlike 

 conditions are acquired characters, what is the 

 objection ? 



In my previous letter (January 13, p. 630) I 

 criticised some of Sir Archdall Reid's statements by 

 pointing out that they contradicted each other. In 

 reply he referred to some supposed views as to what 

 were acquired characters put forward in other pub- 

 lications of mine. But he is not entitled to do this. 

 I made no offer to discuss my own views ; I was 

 merely criticising the arguments by which he 

 attempted to show that all characters were "innate 

 and acquired in exactly the same sense and degree." 

 What I may have written elsewhere is not relevant 

 to the present discussion. In the letter in the issue 

 of Nature for February 3, Sir Archdall Reid takes the 

 case of a normal Englishman and a scarred negro 

 as an example, and states that they differ in scars 

 by acquirement, but that the scars are not acquired 

 any more or less than the skin-colour. It follows, 

 then, either that an acquirement is not acquired or 

 that the skin-colour is also acquired in the same 

 sense and degree as the scars. But the latter is not 

 the case, for the different skin-colours will develop 

 under the same conditions — that is, they do not corre- 

 spond to different conditions, while the scars are 

 related to a difference of conditions or stimuli, 

 namely, injury in the one case which is absent in 

 the other. If Sir Archdall Reid means that no 

 character could be acquired unless the living sub- 

 stance of the organism had the potentialitv of 

 developing in a certain way under certain conditions 

 or under a certain stimulus, that is, of course, a 

 truism which does not require to be stated. But he 

 has entirely failed to prove that all characters are 

 innate and acquired, somatic and germinal, exactlv 

 in the .same sense and degree. His own arguments 

 and examples prove the contrary. 



J. T. Cunningham. 



NO. 2678, VOL. 106] 



Coloured Thinking. 



In view of Prof. Eraser Harris's letter in Nature of 

 February 3 and of his implied complaint that so little 

 has been written on the phenomenon since Galton 

 discovered it, possibly the record of some observations 

 that I made upon my own son more than eleven years 

 ago, when he was between seven and a half and eight 

 years old, may be worth notice. I was in correspond- 

 ence with Galton about the case shortly before his 

 death ; and, in fact, a letter to him, reporting the 

 result of further inquiries suggested by him, was 

 Iving on my desk ready to be posted when I opened 

 the daily paper and read the announcement of his 

 death. 



Having accidentally discovered that my son had 

 coloured concepts, I noted down a series of these in 

 the late autumn of 1909, taking great care to avoid 

 any approach to leading questions or suggestions. 

 Then, three months later, having meantime ignored 

 the matter, I again tested him ; and on this occasion, 

 at Galton 's suggestion, I carried the inquiry rather 

 further. I will deal first with the numerals, since 

 these afforded the most interesting results. Their 

 colours were : 



On the second occasion I tested the obvious infier- 

 ence from his description of the colours of 35, 36, 

 and 55, by asking him the colours of 49, 72, and 14; 

 and my notes state that he made "ready replies." 



49 was blue and green. 

 72 ,, pink and brown. 

 14 ,, black and blue. 



I had already noted his statement that the colours of 

 35, 36, and 55, were "in their proper order." 



Now obviously there is a marked difference 

 between the colours of the numerals above 19 — or 

 possibly above 10 — in this case and those seen by 

 Miss .\. M.; for she sees apparently all the twenties, 

 thirties, forties, etc., in the colour of the first digit; 

 whereas iny son saw each digit in its own colour pnd 

 unaffected by the combination with another. The 

 deliberate tests with 49, 72, and 14, following his 

 account of 35, 36, and 55, and the remark about the 

 "proper order " of the colours, were conclusive on 

 this point. 



There is another matter of interest. Having told 

 me the colour of 8 already, he was surprised at iny 

 asking the colours of 80 and 800, and replied that 

 of course they were the same as 8. In other words, 

 the zero was really zero to him, and therefore had 

 no colour. Now in teaching him arithmetic during 

 the preceding months I had endeavoured to make 



