Feb. 20, 1890] 



NATURE 



;67 



all those fine, invisible "molecular" changes, through which 

 Nature habitually works, and it ascribes to mere outward and 

 mechanical agencies, effects which, alone, we have no reason to 

 suppose they ever can produce. 



On the question of "prophetic germs," Mr. Dyer challenged 

 me to produce a single case of organs useless now, but in course of 

 preparation for future use. I replied by referring him to this 

 phenomenon as universal throughout Nature in the life-history 

 of every individual organism ; and I also referred him to the 

 well-known idea of Darwinian embryology which establishes a 

 close analogy between the laws governing the development of 

 the embryo, and the whole past development of organic life. 



Mr. Dyer replies that I ought to have explained this sooner — 

 when challenged to do so by Prof. Ray Lankester — an observa- 

 tion which has nothing to do with the merits of the question. 

 The truth is, I wished to close my dispute with that distin- 

 guished Professor, as I now desire to close it with Mr. Dyer, 

 and I was satisfied with an indirect admission that, as regards 

 every individual organism, my assertion could not be contra- 

 dicted. What this involves, I left, and now leave again, as 

 unexhausted as it is indeed inexhaustible. 



In conclusion, I must observe upon the use Mr. Dyer makes 

 of the phrase '•^ a priori argument," which he apparently uses 

 not only for all deductive argument, but for all analytical reason- 

 ing. When he says he " has not an a priori mind," he really 

 means that he is indisposed to all analysis. This is a very com- 

 mon attitude even with many able and distinguished men — espe- 

 cially when they are devoted to a system, and are the disciples 

 of some prophet, whose words and phrases they gulp and swal- 

 low whole. It is an attitude which has its use ; but it is not 

 one to boast of. Mr. Dyer's declaration that " the questions at 

 issue with regard to evolution are now, I believe, thoroughly 

 understood by biologists " is the most astonishing utterance I have 

 ever heard or read coming from a scientific man. Discussion 

 with him is useless. He and his friends know all about it. 

 How life began, and how it grew from more to more — the whole 

 secret of creation — "an open scroll, before them lies." I am 

 happy to think that I am not the only searcher — by many 

 thousands — whose pens Mr. Dyer must intervene to stop. 

 There is a great army of us who are conscious above all things 

 of the ignorance of man. Argyll. 



Kinellan, Murrayfield, N.B. 



In the number for January i6 (p. 247) Mr. Thiselton Dyer ob- 

 serves that "there are many readers of Nature who, while 

 taking a general interest in the problems raised by Darwinism, 

 have not followed all that has been written about it." For the 

 benefit of such persons he gives an interesting explanation of 

 Darwin's views on several important points. 



I have not read all that has been written, but all, I think, that 

 has ever appeared in the pages of NA'ruRE, and with the result 

 that I am more and more convinced of the inadequacy of the 

 Darwinian theory to account for the origin of species. Natural 

 selection is a vera causa, but of very limited operation. The 

 theory of sexual selection but partly removes one serious difficulty 

 not of the first magnitude. 



I find Darwinians — not Darwin — very ready to insinuate or 

 assert that an unwillingness to adopt their views, on the part of 

 persons who believe in a supernatural revelation, arises from 

 theological prejudice, which hinders them from listening to the 

 voice of reason. I think there is some prejudice on both sides. 

 For myself, fully believing in a Supreme Designer, I am per- 

 fectly and most fearlessly willing that " the attempt at mechanical 

 explanation" should be carried as far as possible, well knowing 

 that "a final universal cause" cannot possibly be disproved or 

 reasonably denied. And Darwinism is committed to no such 

 denial. 



We have our choice between two alternatives. Life on 

 our globe had a beginning ; and its cause was certainly 

 not mechanical or natural, — for reasons not theological, but 

 strictly scientific, in the technical sense of the word. For, 

 as the laws of Nature operate uniformly, if life had ever com- 

 menced spontaneously, it must of natural necessity do so again 

 and again, since it would be most absurd to suppose that only 

 •during some previous state of the earth's surface did matter exist 

 in such a condition as to be capable of conversion into living 

 things. If life had ever arisen mechanically, it would require a 

 miracle to prevent repetitions of the process. 



We have, then, to take our choice between supposing with 



Darwinians that the life-producing power acted once for all, and 

 supposing that it has acted repeatedly and continuously, in more 

 ways than one. I see no theological, and, let me say, no Scrip- 

 tural, objection to either. Let it be believed willingly, if good 

 reasons can be given, that all life began with a single germ 

 which could not only produce its like — which is wonderful 

 enough — but which even contained in it?elf such amazing 

 potentialities that it could become, and has become, the parent 

 of every form of life, sentient or non-sentient, that has ever 

 appeared on our globe. 



To me this seems scientifically improbable. For why should 

 the power, whether acting intelligently, or, if anyone prefers it. 

 without intelligence, create one germ only ? Why not millions ? 

 And if of one kind, why not of many ? And if single organisms, 

 why not organisms connected with one another, even in highly 

 complex structures ? And why act once only ? Why not start 

 non-sentient life at one time, sentient at another ? For do not 

 sentient things need a separate germ? I take leave to think so. 

 But be this as it may, they are as much in advance of the non- 

 sentient, however much alike those germs we know of may 

 appear to be, as the non-sentient are of inanimate matter. 



The other alternative supposition is that the life-producing 

 power, instead of acting once only, and then subsiding into its 

 primaeval torpor, continues to act. That, as it once acted upon 

 inanimate matter, not robbing it of anything, but rather, while 

 availing itself of its properties, conferring upon it new powers, 

 so it has acted since upon living things, ever producing out of 

 the old new and higher forms of life ; availing itself of all 

 existing faculties of living things, but while allowing them to 

 achieve all that they can, still moulding fresh forms, and con- 

 ferring higher faculties. To suppose this, is only to suppose 

 that the action of the life-producing power, since life began, has 

 been analogous to what we know was its action in producing 

 life. It is hardly to be supposed that the production of one 

 marvellous germ has exhausted all its energy. 



Yet, if the Darwinian theory can enable us to dispense with 

 the aid of this power, let it do so. Let reason prevail. 



Darwinians offer, as an adequate explanation of the formation 

 of new species from the older, that this development comes 

 about simply through natural selection — through the survival of 

 the fittest of favourable variations. 



" The origin of any species," says Mr. Thiselton Dyer, "lies 

 firstly in the occurrence, and secondly in the selection and 

 preservation, of a particular variation." But surely a particular 

 variation alone — that is, such as can be brought about, as we 

 know from experience, in a single generation — does not suffi- 

 ciently differentiate one species from another. Short-horned 

 cattle, for instance, are not a new species, nor would they deserve 

 to be so termed if it should eventually happen that all other 

 varieties of horned cattle became extinct. In the great majority 

 of cases, at all events, there must be more than one particular 

 variation, before we can recognize a specific difference. Species 

 have become what they are by the combination, in one organism, 

 of many particular variations, each well suited to the rest. No 

 particular variation could make of another ruminant a giraffe. 

 What we want, and what seems to be wanting in the Darwinian 

 theory, is a satisfactory hypothesis to explain the concurrence 

 of many particular variations, by the co-existence of which in 

 one structure the new species is constituted. Variations, or 

 "fluctuations," as Mr. Thiselton Dyer has happily termed 

 them, will not account for this. Between some species there 

 may be merely slight and single differences ; but Nature can 

 show us much more than this. We often find a complicated 

 apparatus formed by the concurrence in one individual of many 

 particulars of structure combining to produce an effect wholly 

 peculiar. 



Take the following instance, or rather group of instances. 

 There are venomous serpents, of many species and in many 

 lands, which differ most widely from the non-venomous kinds, 

 from which, or from the ancestors of which, they are generally 

 believed to have been derived. In these we find, to begin with, 

 teeth which have undergone strange modifications. They are 

 needle-like in shape. They are not fixed in the jaw. They 

 occupy a very prominent position. They have minute perfora- 

 tions, terminating near, but not precisely at, the point. They 

 have muscles by which they may be recurved, so that their 

 points may be directed towards the throat. They have hollows 

 in which to lie. They have muscles by which, on occasions, 

 they may be projected beyond the mouth. Besides all this 

 poison-secreting glands, and poison-bags, and channels of com- 



