174 



NATURE 



[February 9, 1922 



between individuals of the same species, and also the 

 larger, more conspicuous departures from the average 

 t)'pe or normal character. The former are now called 

 "fluctuations," the latter "mutations." Sir Archdall 

 agrees that a variation may result either (a) from 

 germinal or (fe) from nurtural differences, ^ but he 

 repeats his assertion that all characters are alike with 

 respect to acquiredness and inheritability. 



Now I presume that when a variation of germinal 

 origin is inherited it is correctly called a "character." 

 For example, the rose-comb in fowls is a character, 

 and we may suppose that it arose as a variation of 

 germinal origin. We know that it is inherited. But 

 Sir Archdall asserts that when it appears in an indi- 

 vidual it is also "acquired " because it was not present 

 in the new-laid egg. Here then he is merely, without 

 any justification, giving a new meaning of his own 

 to the term "acquired," which was applied by bio- 

 logists to those differences which were not of ger- 

 minal origin. He insists on substituting in this case 

 the term "acquirement " for the term "development." 



On the other hand, if a man rows much he develops 

 first blisters, and then corns, on his hands. According 

 to Sir Archdall, this character is inherited because a 

 son would reproduce the character under the same 

 conditions as the parent produced it— that is, under 

 the stimulus of friction due to the handling of the 

 oar. Here again Sir Archdall is giving a meaning of 

 his own to the term "inherited" different from that 

 which biologists originally intended and understood. 

 Supposing the rowing man's father never had such 

 corns, still, according to Sir Archdall, the corns would 

 be inherited. Biologists would say that the corns 

 were acquired as the result of the external stimulus. 



What I wish to point out is that this alteration in 

 the meaning and definition of terms is due to a funda- 

 mental misunderstanding of biological processes. Sir 

 Archdall states that a fowl reproduces the comb in 

 response to nurture similar to that of its parent, and 

 the man reproduces the corn in response to nurture 

 similar to that under which his parent would have 

 produced it ; therefore both are inherited and both are 

 acquired. What is the resemblance between the 

 two cases? The fowl is nourished by the yolk of 

 the egg before hatching and by its food after 

 hatching; it has a supply of oxygen and temperature 

 within certain limits, and "in response" to these 

 conditions the comb develops. The man is nourished 

 by nutriment before birth, by food after birth, 

 requires oxygen and warmth, and then his hands 

 are subjected to friction and the corns develop. It 

 is a manifest absurdity to say that the two cases 

 are of the same kind or analogous. It is easy 

 enough to reduce two different phenomena to the 

 same form of words and then assert that they are of 

 the same kind ; it may show ingenuity, but it obscures 

 the truth, and is contrary to the methods of science. 



The fallacy of Sir Archdall 's argument lies in the 

 words "in response to." After admitting the differ- 

 ence between two kinds of variation, he maintains 

 that the comb, or, taking the more special character, 

 the rose-comb, develops in the offspring in response to 

 similar nurture, i.e. the same -conditions as in the 

 parent, and that precisely the fame may be said of 

 .corns produced by rowing. But thrs is not the truth; 

 it is the exact opposite of the truth. The rose-comb is 

 not a "response" to any of the conditions of the 

 nurture. We may take cocks and hens which are the 

 produce of a cross between rose-comb and single 

 comb, and which all have rose-combs ; when we breed 

 from them some of the chicks develop single combs 

 and some develop rose-combs. Which comb-character 

 is the "response " to the similar nurture, parents and 

 offspring having all had the same nurture? 

 NO. 2728, VOL. 109] 



Sir Archdall fails to perceive the difference between 

 a condition or stimulus in the nurture which has a 

 direct relation to a structural feature and conditions 

 which have no such relation. In the case of the 

 corns due to rowing, the increased growth is a definite 

 response to the stimulus of friction. In the nurture 

 of fowls there is no stimulus to which the comb or 

 any comb-character is a response. A character is 

 inherited, not necessarily under the same conditions, 

 but under a great variety of conditions, and vast 

 numbers of different characters are inherited under the 

 same conditions. Consider the various plants in a 

 garden : their characters cannot be said to develop 

 in response to nurture. No stimulus or treatment 

 will produce a purple sweet-pea from a white sweet- 

 pea ; apart from variations, the different varieties of 

 plants develop the characters of their parents in the 

 same garden under the same conditions. When a 

 stimulus is found which produces a certain change, 

 then that change is an acquired character. 



It is an essential point that the fowl develops 

 in response to nurture, but not the comb-character or 

 any other inherited character. Heat at a certain 

 temperature is a necessary stimulus to the development 

 of the egg, but it is not a stimulus to any particular 

 character. The eggs of all the various breeds with 

 all their remarkable colours and other characters can 

 be incubated at the same temperature. It is a fallacy 

 to place the relation of heat to general development 

 in this case in the same category as the relation of 

 friction to corns in the other. The question is : What 

 determines the character? Friction of the hands pro- 

 duces a particular structural change ; heat in Incuba- 

 tion has no effect whatever on the characters of the 

 breed to which the eggs belong. 



Sir Archdall has stated that the corns due to 

 rowing are inherited, and has treated them as a 

 character. In this case, what becomes of the differ- 

 ence between a character and a variation? We may 

 suppose a family of people who have not practised 

 rowing ; one adopts the practice and develops corns. 

 Are these a character or a variation? Is the rose- 

 comb a character or a variation? Sir Archdall has 

 tried to show that the two are characters of the same 

 kind with regard to acquirement and inheritability. 

 But if they are variations, what becomes of the two 

 kinds of variation? 



Readers of Nature are probably as weary of this 

 controversy as I am, but Sir Archdall Reid is doing 

 much harm by leading many who have no special 

 knowledge of heredity and evolution to distrust the 

 work of those who are engaged in research on these 

 subjects. Prof. Bayliss recently stated that It was 

 clear from this correspondence that the actual mean- 

 ing of the terms used was in dispute. I feel that it 

 is necessary, therefore, to crltl'^Ise Sir Archdall 's 

 statements. J. T. Cunningham. 



East London College, Mile End, E., 

 January 28. 



In his recent letter to Nature (January 26, p. 104) 

 Sir Archdall Reid restates his belief that "all charac- 

 ters are alike as regards innateness, acquiredness, 

 and Inheritability.'' His difficulties in this matter 

 appear to be largely of his own creation, and they 

 might be dissipated If he paid less attention to words 

 and greater attention to the facts of experimental 

 biology. 



Sir Archdall Reid admits that there are "two kinds 

 of variation : (a) those which result from germinal, 

 and (b) those which result from nurtural, differences." 

 That being the case. It surely follows that there are 

 two kinds of characters ; for what is a character but 



