JANUARY 12, 1922] 



NATURE 



41 



period they decided to be false to their obligation is a 

 matter of secondary moment. 



The implication that the Allies were contemplating 

 the use of poison gas as early as September, 1914, is 

 >o notoriously at variance with truth that it scarcely 

 needs serious refutation. If Geheimrat Haber could 

 only have been present when Lord Kitchener made 

 nis dignified protest in the House of Lords, or have 



■ en a personal witness of the :vave of indignation 

 nd disgust which swept over the country at the Ger- 

 mans' breach of the rules of war, he would not have 

 penned his statement. We were made aware of the 

 rumours that were being spread through the German 

 Press, but no credence was attached to them in this 

 country. The German Empire, even to the last, had 

 Its "reptile Press " as in the days of the Iron Chan- 

 trellor. The author of the Ems telegram was an 

 adept in the art of circulating false rumours and 

 misleading statements, and there were those who 

 sought to better even his example during the fateful 

 and, for the Germans, disastrous years of the war. 

 Even now Germanv does not know half the truth. 



I agree with Prof. Haber that in war-time men are 

 apt to think otherwise than thev do in peace, and 

 this is, doubtless, particularly true of his countrv- 

 men. Their ethical standard, apparentlv. varies with 

 the two conditions — which seems a sufficient reason 

 why thev should abstain from war. Those who use 

 poison gas are not "bonnie fechters." 



The menace of the continued use of poison gas in 

 warfare is a disgrace to civilised humanitv. That 

 menace really rests with Germanv. If she would 

 undertake for the future to be true to her obligation 

 imder the Hague Convention other nations would 

 willingly follow her example. 



Thev were reluctantlv compelled to follow it in 

 consequence of her action at the Battle of Yores. 

 Thev would far more oromptlv follow her lead if she 

 announced her intention to discontinue the practice 

 and gave the world a sufficient assurance of good 

 faith. 



Prof. Haber could render no greater service to 

 civilisation and humanity than (to use Tiis great 

 influence and pre-eminent position as a man of 

 science in inducing his felIo\v-countni'men to remove 

 what is a stigma upon their Kiiltur. 



T. E. Thorpe. 



Some Problems in Evolution. 



I .1M quite as averse from " wasting time in endless 

 nnd futile controversy " as Prof. Goodrich, but I 



mnot help thinking that so long as he and Sir 

 wchdall Reid refuse to admit what seem to most 

 biologists obviously true statements their arguments 

 must be answered. Prof. Goodrich states in Nature 

 of December 22 last that there is no contradiction 

 between his proposition that characters, whether new 

 or ancient, may be inherited provided they are pos- 

 sessed by both parents, and mv reply that a character 

 may be inherited when it is apparent only in one 

 parent or in neither. If we omit what is common 

 to both of these propositions it follows that in Prof. 

 Goodrich's opinion there is no difference between 

 "both parents" on one hand and "one or neither 



irent " on the other. 



Prof. Goodrich complains that I do not distinguish 

 between the variation and the resulting character. 

 In his presidential address he maintained that the 

 word "variation " should mean the extent or degree 

 of difference between individuals, not a new character 

 or assemblage of characters, such as a colour or spot 

 on a butterfly's wing, but a difference which can be 

 NO. 2724, VOL, 109] 



measured or estimated. "We shall then find," he 

 writes, " that a variation is either due to some change 

 in the complex of germinal factors or to some change 

 in the complex of effective environmental stimuli." 

 Here Prof. G(K>drich and I are in complete agreement. 

 Where, then, is any difference of opinion or room for 

 controversy? The difficulty reappears in the next 

 paragraph o( Prof. Goodrich's letter, in which he 

 states that he agrees with Sir Archdall Reid that 

 there are two kinds of variation but only one kind 

 of character. 



Although I have honestly tried to do so, I fail to 

 see any meaning in this statement. After all, words 

 and terms are seldom completely satisfactorv expres- 

 sions of what we mean ; they obtain their meaning by 

 actual or implied reference to facts of observation. 

 I have lately been in the habit of using the term 

 "character" more frequently than the term "varia- 

 tion," because the latter is often ambiguous, but I 

 know of no such difference of meaning between the 

 two terms as is assumed b}' Prof. Goodrich and Sir 

 Archdall Reid. How can we define characters satis- 

 factorily except by comparison— that is, as differences 

 between one individual, or one type, and another? For 

 example, the rose comb is a character of certain fowls 

 as compared with the single comb. What do we 

 gain by asserting that the difference between the rose 

 comb and the single is a variation, but the peculiarity 

 of the rose comb is a character? The only questions 

 of importance are the origin and the heredity of the 

 rose comb. We understand one another when we say 

 that the rose comb is inherited. It is quite superfluous 

 to insist, as Sir Archdall Reid does, that characters 

 are not transmitted, but only predispositions. No one 

 supposes at the present day that the fowl's egg or 

 spermatozoon has a rose comb, but we know that 

 there may be something, whether we call it deter- 

 minant, factor, or gene, in egg or sperm which causes 

 the rose comb to develop in the resulting organism. 

 And yet Sir Archdall Reid argues as though it were 

 a remarkable discovery that characters are not 

 present as such in the fertilised ovum from which an 

 organism develops — an idea that has been obsolete 

 since the Middle .\ges. Therefore, he asserts, there 

 is only one kind of character, but there are two kinds 

 of variation. The hoof of a new-born foal has 

 developed without any external mechanical stimulus ; 

 when I practise rowing for some time I develop 

 epidermic corns on the palms of my hands. According 

 to Sir Archdall Reid, these are characters of the same 

 kind, equally innate, acquired, and inherited. Yet he 

 has himself insisted on the distinction between charac- 

 ters developed under the "stimulus of nutrition " and 

 those developed under the "stimulus of use," the 

 same distinction, with his own peculiar misuse of the 

 word stimulus, which is generally recognised by 

 biologists. 



Avoiding altogether the use of the terms "varia- 

 tion " and "character," we may congratulate our- 

 selves that there is agreement on the proposition that 

 a difference of form or structure may be due either 

 to a difference of germinal factors or to a difference in 

 effective environmental stimuli. And then we can 

 get on with the investigation of the problem of the 

 relation to evolution of these structural differences. 



But, as I have endeavoured to show elsewhere, 

 among those characters which are more or less com- 

 pletely hereditary there are two kinds, in a vast 

 number of cases definitely distinguishable: theadap- 

 tivc characters on one hand and the non-adaptive on 

 the other. The adaptive characters exhibit a definite 

 relation to habits and external conditions, and, as a 

 rule, they exhibit recapitulation in development. The 



