August 30, 1888] 



NATURE 



411 



pauperism ; education ; illiteracy ; prices of commodities ; 

 and prices of wheat. Students who may wish to know 

 the recent history of London with regard to any one 

 of these subjects will at once find what they want by 

 turning to the diagram or diagrams referring to the 

 matter. Opposite each diagram are short notes indi- 

 cating clearly and concisely what the curves appear to 

 teach, and directing the reader to the original sources 

 from which the facts are taken. It is impossible to turn 

 over these pages without feeling, as the author does, that 

 if some improvement of the social condition of London is 

 discernible it is, after all, but meagre. Probably, too, 

 most people who make themselves familiar with the results 

 he has so carefully classified, and rendered so easily in- 

 telligible, will agree with him that in dealing with the 

 social problem we as a people are apt to think too much 

 about cure, and too little about prevention. " Year by 

 year," says Mf. Macdowall in his interesting preface, "we 

 reap, somewhat sadly, our weedy crop ; but we leave the 

 weed-roots in the ground. To use another figure, we 

 contend in a vigorous way with the waters of a domestic 

 deluge, but omit to turn off the tap from which they 

 come." 



A System for the Construction of Crystal Models. By 

 John Gorham, M.R C.S.Eng., &c. (London and New 

 York: E. and F. N. Spon, 1888.) 



The author of this book expounds an ingenious method 

 of making models in paper by plaiting together three or 

 four strips cut into the form of a succession of the crystal 

 faces. The book consists mainly of figures, which show 

 how these plaits are to be drawn, and the order in which 

 they are to be interwoven for some of the primitive forms 

 in the different systems. 



It does not appear that the models are more easily or 

 neatly made by this than by the more familiar methods, 

 but they have one real advantage in their portability, 

 since they may at any time be unfolded into a flat sheet. 

 The method would, however, be somewhat awkward 

 when applied to complicated combinations. 



Some of the simple forms are omitted in the descrip- 

 tion?, e.g. the icositetrahedron, pentagonal dodecahedron, 

 &c, and it is hardly necessary to remark that the four- 

 faced cube is not a form assumed by some varieties of 

 quartz (p. 8). We hesitate to believe the author serious 

 in his suggestion that a natural cube may actually grow 

 by plaiting itself from three zones of molecular laminae, 

 " each endowed with a force compelling it to bend at a 

 right angle at given intervals." 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he under- 

 take 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 communi- 

 cations. ,] 



Functionless Organs. 



I have only just seen Nature for August 16 and 23 (pp. 364 

 and 387). In both these there are letters which attribute to me 

 personally the assertion that the electric organs in "the skate" 

 are functionless, and are "on the way to use" — not aborted or 

 degenerated from former use. I made no such assertion. My 

 letter on the subject referred to a verdict given on this question 

 in respect to one particular species [A'aia radiala) by Prof. 

 Ewart inNATUREof July26 (p. 310). I refer Prof. Ray Lankester 

 to the paper of Prof. Ewart, communicated to the Royal Society 

 through Prof. J. Burdon-Sanderson. As the result of an elabo- 

 rate argument, founded on anatomical details, the author con- 

 •cludes that the "cups of Raia radiala are in process of being 

 elaborated into more complex structures"; and again, "that 

 the electric organ of Raia radiata, notwithstanding its apparent 

 uselessness and its extremely sma'l size, is in a sta'e of progressive 

 •development." 



This is not my conclusion, but the conclusion of an expert, 

 who gives his reasons, and differs from Prof. Ray I.ankester in 

 having, apparently, no preconceived theory to support. 



If the doctrine of evolution be true — that is to say, if all 

 organic creatures have been developed by ordinary generation 

 from parents — then it follows of necessity that the primeval 

 germs must have contained potentially the whole succeeding 

 series. Moreover, if that series has been developed gradually 

 and very slowly, it follows also, as a matter of necessity, that 

 every modification of structure must have been functionless at 

 first, when it began to appear. On this theory it seems to me 

 to be not a matter of argument, but a matter of certainty, that 

 all organic nature must have been full of structures "on the 

 rise," as well as of others on the decline. 



Why is this not recognized? Because organs "on the rise" 

 cannot be due to utility as a physical cau-e, but mu-t be due to 

 utility as an end yet to be attained. This is what I mean by a 

 "prophetic germ." We now know that Darwin resisted and 

 rejected this idea, at least at one time of his lite, as fatal to his 

 own theory of natural selection. And so it is, if natural selec- 

 tion is made to account for structures before they are presented 

 for selection to act upon. But this is obviously nonsense. Things 

 cannot be selected until they have been first produced. Nor 

 can any structure be "selected by utility in the struggle for 

 existence " until it has not only been produced, but has been so 

 far perfected as to be actually used. 



If Prof. Ray Lankester will explain how "natural selection " 

 can act upon "congenital variations" which he calls "non- 

 significant" — i.e. which are not yet of any actual use — and if he 

 will explain how this action can afford " the single and sufficient 

 theory of the origin " of (as yet) useless variations, he will have 

 accomplished a great triumph in logic and philosophy. 



Meantime, I adhere to that view of all organs which is 

 indelibly in pressed on our very forms of speech, and is notably 

 expressed in Prof. Buidori-Sanderson's letter in Nature of 

 August 23. He speaks of electric organs as "an apparatus for 

 producing electric discharges." This is exactly correct. They 

 are " apparatuses" for a special purpose or function ; and like 

 all other apparatuses, they have to be prepared through embryotic 

 stages in which they are not capable of use. I have been long 

 looking for some actual case in which experts should recognize 

 an organ " on the rise." Prof. Ewart's is the first I have seen. 

 I am not responsible for his facts, or for his reasoning. But the 

 mere fact of such a view being taken by an eminent man in a 

 responsible position is a circumstance highly significant. 



The recognitionof even one case wdl be the recognition of anew 

 idea — new, at least, in its application, and new in its wide signi- 

 ficance of interpretation. Jt will be the counterpart in actual 

 observation of that strategic movement in abstract reasoning 

 which has recently led Mr. Herbert Spencer to expose the fal- 

 lacies involved in the phrase "natural selection," and in his 

 own neater and adroiter form of it, " survival of the fittest." 



Argyll. 



I have read with much interest the report in Nature of July 

 26 (p. 310) of Prof. Ewart's very remarkable paper on the electric 

 organ of the skate, and the Duke of Argyll's letter on the same 

 subject in Nature of August 9 (p. 341). The Duke is manifestly 

 right, that a single proved instance, such as Prof. Ewart here en- 

 deavours to make out, of an organ which has been evolved, or i;; 

 in process of evolution, while not in a state of functional activity, 

 would be sufficient to disprove Darwinism as a complete theory ; 

 for if all perfectionment is due to the two causes of exercise 

 through habit and natural selection among variations, it is 

 obvious that no improvement can be effected which is not 

 immediately useful. 



I believe that the animal kingdom, and in all probability the 

 vegetable kingdom also, are full of organs which cannot have 

 been evolved by anything like a Darwinian process, because 

 their immature states cannot have been in functional activity. 

 In my work on " Habit and Intelligence " (2nd edition, Mac- 

 millan, 1879), chapters xvii., xviii., and xix., I have enumerated 

 some of these. The strongest part of the argument is, 1 think, 

 that derived from the brain of man. It has been pointed out by 

 Wallace, the naturalist who was near anticipating Darwin in the 

 theory of natural selection as applied to the rest of the organic 

 creation, that the brain of savage man has attained a develop- 

 ment which is out of all proportion larger than can correspond to 

 the mental development which is united with it — in other word?, 

 the brain of savage man is nearly equal to that of civilized man, 



