Jan. 1 6, 1890] 



NATURE 



247 



OUR BOOK SHELF. 



FIouier-Latid : an hitroduciion to Botany. By Robert 

 Fisher, M.A., Vicar of Sewerby, Yorks. (London: 

 Bemrose and Sons, 1889.) 



This is a capital first book of botany, intended for small 

 children. The style, however, is really more elementary 

 than the matter, and a child who has mastered this book 

 will have made a very good start in the science. There 

 is a good deal of information given about the internal 

 structure and function, as well as the external form, of 

 the organs of plants, and this information is given cor- 

 rectly, as well as clearly. 



The book is illustrated by 177 woodcuts, most of which 

 are well suited to their purpose. D. H. S. 



Five Months^ Fine Weather in Canada, Western U.S., 

 and Mexico. By Mrs. E. H. Carbutt. (London : 

 Sampson Low and Co., 1889.) 



In this book Mrs. Carbutt records her experiences during 

 a remarkably pleasant journey made by herself and her 

 husband in the New World. The scenes she describes 

 have often been described before, but she writes so brightly 

 about what she saw that even readers to whom she has 

 nothing new to tell will find a good deal to interest them 

 in her narrative. They will be particularly pleased with 

 her account of " sunny Mexico, and its merry, courteous 

 people." 



LETTERS TO THE EDITOR. 



( The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents . Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature, 

 No notice is taken of anonymous communications. '\ 



The Duke of Argyll and the Neo-Darwinians. 



It has a curious and not uninstructive effect to see the 

 pages of this journal invaded by the methods of discussion 

 which are characteristic of political warfare. The letter of the 

 Duke of Argyll, published in Nature for December 26, 1889 

 (P- 173) is a clever debating speech. But it rather obscures than 

 illuminates the questions really at issue. And, after the fashion 

 of the political orator, it attributes to those who disagree with 

 the writer motives which, in so far as they differ from reasoned 

 conviction, are essentially insincere. 



In politics, the personal rivalry which is bound up inextricably 

 with the solution of great problems may make it a necessary 

 part of the game to endeavour to belittle one's opponents. But 

 in science it is not so. The newer problems which have been 

 raised by Darwinism depend for their solution upon the discussion 

 of evidence, and no competent biologists will, in the long run, 

 be influenced in the opinions they form about them by anything 

 else. 



There is nothing in the Duke's letter which has not been worn 

 threadbare by discussion. Still, there are, no doubt, many 

 readers of Nature who, while taking a general interest in the 

 matter, have not followed all that has been written about it. I 

 am disposed to think, therefore, that it may not be without its 

 use to go over the ground which the letter covers. 



First, as to acquired characters. Let us take a simple case. 

 It is admitted that a blacksmith, by the constant use of his arms, 

 may stimulate their abnormal muscular development ; that is an 

 acquired character. But a working man, whose arms are of per- 

 fectly average dimensions, may nevertheless have a son with 

 arms which would seem to mark him out for the blacksmith's 

 profession ; that would be a congenital variation. Now we 

 know that a congenital variation is likely to be inherited ; that 

 is a matter of observation. What is the case as to the acquired 

 character? The answer must be, I take it, that there is no 

 probability that the arms of a blacksmith's son will differ in any 

 respect from those of the average inhabitant in the locality where 

 he was born. The Duke of Argyll, however, suggests that there 

 is "no necessary antagonism between congenital variation and 

 the transmission of acquired characters." This is perfectly 



reasonable ; theoretically, there is none. But this does not 

 make the transmission of acquired characters less doubtful. 

 The Duke has no doubt about it, however. "So far from its 

 being unproved, it is consistent with all observation and all 

 experience. It lies at the foundation of all organic develop- 

 ment." Very possibly, but where is the observation and where 

 is the experience ? These are the biological desiderata of the 

 day. Imagine the fate at the Duke's hands of any scientific 

 writer who put forward statements such as these unsupported by 

 a shred of a fact. 



" This being so," however, the question then arises, Why do 

 extreme Darwinians so fiercely oppose the idea of the trans- 

 mission of acquired characters ? Well, it is obvious that they do 

 so because they think the evidence in its favour insufficient, and 

 it is clearly the duty of a scientific man, whether an extreme 

 Darwinian or not, to oppose the acceptance of that which ex- 

 perience does not support. But the Duke of Argyll attributes 

 their opposition to two causes : first, jealousy of associating the 

 names of Lamarck and Darwin ; and, secondly, the dethrone- 

 ment of their idol Fortuity. The first of these reasons is almost 

 too preposterous to discuss. No serious naturalist would speak 

 with other than respect of Lamarck's position in scientific 

 history ; this cannot be effaced however much that of Darwin 

 may be magnified. And no serious naturalist would adhere to 

 any theory Darwin had propounded a moment longer than the 

 evidence seemed to carry conviction. The charge in this par- 

 ticular matter is, however, the more grotesque, because, although 

 Darwin did not esteem as of much value Lamarck's doctrine of 

 development and progression, we know that his own mind 

 became more and more fluid on the question of the "direct 

 action of conditions." The idea is in fact so plausible that the 

 difliculty is not in accepting it, but in shaking oneself free from 

 it. What were probably the last words which Darwin wrote on 

 the subject are contained in a letter to Prof Semper, dated 

 July 19, 1 88 1. I quote a passage which appears to me to 

 pretty accurately define the present position of the question : — 



" No doubt I originally attributed too little weight to the direct 

 action of conditions, but Hoffmann's paper has staggered me. 

 Perhaps hundreds of generations of exposure are necessary. It 

 is a most perplexing subject. I wish I was not so old, and had 

 more strength, for I see lines of research to follow. Hoffmann 

 even doubts whether plants vary more under cultivation than in 

 their native home and under their natural conditions (" Life and 

 Letters," vol. iii. p. 345). 



Darwin's difficulty, in point of fact, was exactly that of every- 

 one else. The evidence, instead of being " consistent with all 

 observation and all experience," failed to be forthcoming. 



The second reason is equally baseless. Fortuity is no idol of 

 the neo-Darwinians ; if h is an idol at all, it is an " idol of the 

 market," imposed upon their understanding by the Diike. But 

 at any rate he does not attribute any blame to Darwin. And as 

 this is a rather important matter, on which I admit that persons 

 who ought to know better have gone astray, I will quote a 

 passage on the subject from Prof Huxley's admirable biography 

 (Proc. Roy. Soc, No. 269) : — 



"Those, again, who compare the operation of the natural 

 causes which bring about variation and selection with what they 

 are pleased to call 'chance,' can hardly have read the opening 

 paragraph of the fifth chapter of the ' Origin' (ed. I, p. 131) : 

 ' I have sometimes spoken as if the variations .... had been 

 due to chance. This is of course a wholly incorrect expression, 

 but it seems to acknowledge plainly our ignorance of the cause 

 of each particular variation.'" 



It is obvious that the use of accidental in the guarded sense in 

 which it is employed by Darwin is widely different from for- 

 tuitous as employed by the Duke of Argyll. Darwin took 

 variation as a fact of experience. Its causes and laws have still 

 to be worked out. One of the latter, due to Quetelet, was ex- 

 plained by Prof. George Darwin in this journal (vol. viii., 1873, 

 p. 505). He says : "One may assume, with come confidence, 

 that under normal conditions, the variation of any organ in the 

 same species may be symmetrically grouped about a centre of 

 greatest density." 



And this is quite in accord with the remark of Weismann that 

 variability is not something independent of and in some way 

 added to the organism, but is a mere expression for the fluctua- 

 tions in its type. Variation is therefore not unlimited, and we 

 must admit with Weismann that its limits are determined hy 

 " the underlying physical nature of the organism ; " or as he 

 again puts it, " under the most favourable circumstances a bird 



