August i8, 1923] 



NA TURE 



237 



Letters to the Editor. 



[ The Editor , does not hold himself responsible for 

 opinions expressed by his correspondents. Neither 

 can he undertake to returti^ nor to correspond with 

 the writers of rejected manuscripts intended for 

 this or any other part of Nature. No notice is 

 taken of anonyjnous conununications.^ 



Breeding Experiments on tlie Inheritance of 

 Acquired Characters. 



[At the request of the Editor of Nature, and of 

 Dr. Kamraerer, I have translated this letter from the 

 original German into English. Dr. Kammerer has 

 also sent me the typewritten script of a reply to Mr. 

 Cunningham, but in an accompanying letter he tells 

 me that he considers it superfluous to publish this 

 now, as he is quite satisfied with the reply which I 

 made to Mr. Cunningham in my letter to Nature 

 published on June 23. E. W. MacBride.] 



To begin with, may I remark that I have not seen 

 Mr. Bateson's first criticisms of my work (Nature, 

 July 3, 1919, P- 344) which he cites in the course of 

 his recent letter. Whilst I was in England, my 

 colleagues informed me of the contents of Mr. 

 Bateson's letter of 1919, but I had unfortunately no 

 opportunity of referring to this letter mvself. I 

 regret this all the more, since if what I had been 

 informed of its contents was actually in the letter, it 

 would not have been possible for me to enter into any 

 discussion of the subject with Mr. Bateson himself. I 

 must therefore for the present confine myself to his 

 most recent letter (Nature, June 2, p. 738) and the 

 remarks which he made on the discussion which 

 followed my lecture to the Linnean Society,^ in which 

 he expressly apologised to me in case I had considered 

 his previous attacks too rude. 



It is indeed remarkable that Mr. Bateson on that 

 occasion (May 10) did not produce a single one of the 

 many objections which are contained in his printed 

 letter of June 2. The general impression which I 

 gained at the meeting was that he could not think 

 of any further objection to raise. The " vague 

 diagrams " which he complained of appear not to 

 be derived from my original paper (1909, Archiv 

 ftir Ent. Mech., vol. 28, Plate 16, Figs. 25 and 26), 

 but — if I am not mistaken — from Plate (" Selektions- 

 prinzip," 4th edition, p. 469, Fig. 95) in which my 

 simple figures have been rather strongly altered and 

 exaggerated. 



Mr. Bateson must, therefore, have discovered by 

 subsequent reflection all that during my demonstra- 

 tion and lecture he did not see. Otherwise it might 

 have been possible for me to make him to see what 

 he did not wish to see ; I would certainly, for his 

 benefit, have removed the Alytes specimen from the 

 jar and he would have been able to view it — without 

 obscuration by glass or background — from all sides 

 under the lens : I treated it in this way during my 

 stay in England for many colleagues (as, "^for example, 

 for Mr. E. C. Boulenger and Sir Sidney Harmer). 



On the occasion of the meeting of the Cambridge 

 Natural History Society, I had at my disposal a 

 Zeiss binocular microscope. Every unprejudiced 

 observer could convince himself by its aid that the 

 skin-area under discussion was of the nature of a 

 nuptial pad — an area which according to Mr. Bateson 

 was merely " a piece of thickened blackish-brown skin." 



Numerous are the reasons which Mr. Bateson has 

 given in order to be " absolved from basing broad con- 

 clusions on his testimony " ; in a word, in order to deny 



' Naturk, May 12, 1923, p. 639, column 2, line 10, should read 

 " m.irroscopic observation," not "microscopic." 



NO. 2807, VOL. I 12] 



the existence of the nuptial pads. First he questioned 

 the existence of the pad ; then he suggested it was 

 merely a black patch of pigment ; then, that it 

 was present in only one specimen — consequently an 

 accidental monstrosity ; then he asserted that it was 

 a shadow which appeared in the photograph ; then, 

 even that it had been produced by artificial retouching 

 " in the wrong place," that is to say, on the outermost 

 smallest finger, where in my untouched photograph 

 (1919) some dirt had accidentally remained adhering. 

 The microtome-sections of the pad-tissue, Mr. Bateson 

 suggested, had been taken from another type of 

 Anuran ; then, since it appeared that homologous 

 tissues of other species of Anura were of a different 

 character, that these sections did not show genuine 

 pad-tissue. 



The most recent communication in which Mr. 

 Bateson gives the impression which he received from 

 the specimen which I demonstrated at the Linnean 

 Society is capable of only two explanations, namely, 

 either that Mr. Bateson is not an acute observer or 

 that his theoretical views have affected his vision. In 

 neither case can he escape the criticism that in describ- 

 ing " Dr. Kammerer's Alytes " he proceeded with a 

 rashness unusual in a scientific man, especially when 

 he makes slightly veiled accusations of " correcting 

 Nature " against conscientious observers. We may 

 now enumerate the points on which Mr. Bateson's 

 " doubtful memory " has led him astray, namely : 



(i) It is incorrect to say that my preparation of 

 Alytes prevented a view of the dorsal aspect of the 

 hand and only showed the palmar aspect — to make 

 such a preparation it would have been necessary to 

 fasten each finger fiat against the substratum. 



(2) It is incorrect to say that the black colour is 

 restricted to the palmar aspect. (Why should Mr. 

 Bateson assert this when he had not seen the dorsal 

 aspect ?) Actually the pads extend to the dorsal 

 aspect and are therefore not " in the wrong place." 

 It is curious to find Mr. Bateson prescribing to Nature 

 the " right" place — Nature which has produced much 

 more " astounding " and " curious creatures " (cf, 

 Trichobatrachus) than my modest cultures of Alytes. 



(3) It is incorrect to say "The right hand showed 

 nothing special." On the inner side of the wrist- 

 joint, on the insertion of the ball of the "thumb," 

 there has been regenerated^ a distinct dark pad — 

 of course, not so large as that on the left hand. 



(4) It is incorrect to say that the pad presents only 

 " a dark uniform surface but no papillary or thorny 

 structures." I send herewith an enlarged photo- 

 graph in which " rugosities " can be seen on the edge 

 of the pad with the naked eye. [I have verified this, 

 but doubt very much whether the rugosities would 

 appear in a print reproduced in Nature. — E. W. M.] 

 Unfortunately this photograph is taken from the 

 palmar aspect ; it was not foreseen that Mr. Bateson 

 would criticise this, the most advantageous, position, 

 in order to deny the presence of the pad on the dorsal 

 surface, and to call in question the pad-nature of the 

 whole structure. It is probable that the majority 

 of my English colleagues have no idea how difficult 

 it is to obtain a satisfactory photograph in our 

 impoverished Austria. Of course, at the very first 

 opportunity I shall have the upper side photographed ; 

 perhaps Mr. Bateson in his desire for truth will pro- 

 vide the necessary camera and photographic materials. 



Dozens of scientific men have seen the pads and 

 are now convinced ; only Mr. Bateson has seen 

 nothing. Unfamiliar as he is with this special depart- 

 ment, he expects to see the same as can be seen in 



• Dr. Kammerer stated at the meeting of the Linnean Society that the 

 original pad on the right hand had been removed for the purpose of making 

 microtome sections. — E. W. M. 



I 



