August 25, 1904] 



NA TURE 



407 



phenomena, and possessing sufficient experience of these 

 matters to recognise absurdity in statement and deduction, 

 ready to provide that healthy atmosphere of instructed 

 criticism most friendly to the growth of truth. 



Elsewhere I have noted the paradox that the appearance 

 of the work of Darwin, which crowns the great period in 

 the studv of the phenomena of species, was the signal for 

 a general halt. The "Origin of Species," the treatise 

 which for the first time brought the problem of species fairly 

 within the range of human intelligence, so influenced the 

 course of scientific thought that the study of this particular 

 phenomenon — specific difference — almost entirely ceased. 

 That this was largely due to the simultaneous opening up 

 of lines of research in many other directions may be granted ; 

 but in greater measure, I believe, it is to be ascribed to the 

 substitution of a conception of species which, with all the 

 elements of truth it contains, is yet barren and unnatural. 

 It is not wonderful that those who held that specific differ- 

 ence must be a phenomenon of slowest accumulation, 

 proceeding by steps needing generations for their perception, 

 should turn their attention to subjects deemed more amenable 

 to human enterprise. 



The indiscriminate confounding of all divergences from 

 t\pe into one heterogeneous heap under the name " Vari- 

 ation " effectually concealed those features of order which 

 the phenomena severally present, creating an enduring 

 obstacle to the progress of evolutionary science. Specific 

 normality and distinctness being regarded as an accidental 

 product of exigency, it was thought safe to treat departures 

 from such normality as comparable differences : all were 

 " variations " alike. Let us illustrate the consequences, 

 frincess of Wales is a large modern violet, single, with 

 stalks a foot long or more. Marie Louise is another, with 

 large double flowers, pale colour, short stalks, peculiar 

 scent, leaf, &c. We call these " varieties," and we speak 

 of the various fixed differences between these two, and 

 between them and wild odorata, as due to variation ; and, 

 again, the transient differences between the same odorata 

 in poor, dry soil, or in a rich hedge-bank, we call variation, 

 using but the one term for differences, quantitative or quali- 

 tative, permanent or transitory, in size, number of parts, 

 chemistry, and the rest. We might as well use one term 

 to denote the differences between a bar of silver, a stick of 

 lunar caustic, a shilling, or a teaspoon. No wonder that 

 the ignorant tell us they can find no order in variation. 



This prodigious confusion, which has spread obscurity 

 over every part of these inquiries, is traceable to the original 

 misconception of the nature of specific difference, as a thing 

 imposed and not inherent. From this, at least, the earlier 

 experimenters were free ; and the undertakings of Gartner 

 and his contemporaries were informed by the true conception 

 that the properties and behaviour of species were themselves 

 specific. Free from the later fancy that but for selection 

 the forms of animals and plants w'ould be continuous and 

 indeterminate, they recognised the definiteness of species and 

 variety, and boldly set themselves to work out case by case 

 the manifestations and consequences of that definiteness. 



Over this work of minute and largely experimental 

 analysis, rapidly growing, the new doctrine that organisms 

 are mere conglomerates of adaptative devices descended like 

 a numbing spell. By an easy confusion of thought, faith 

 in the physiological definiteness of species and variety passed 

 under the common ban which had at last exorcised the demon 

 Immutability. Henceforth no naturalist must hold com- 

 munion with either, on pain of condemnation as an apostate, 

 a d.-mger to the dynasty of Selection. From this oppression 

 we in England, at le.ast, are scarcely beginning to emerge. 

 Benlham's "Flora," teaching very positively that the 

 primrose, the cowslip, and the oxlip are impermanent 

 varieties of one species, is in the hand of every beginner, 

 while the British Museum Reading Room finds it un- 

 necessary to procure Gartner's '^ Bastarderzeugnui^.^^ 



.\nd so this mass of specific learning has passed out of 

 account. The evidence of the collector, the horticulturist, 

 the breeder, the fancier, has been treated with neglect, and 

 sometimes, I fear, with contempt. That wide field whence 

 Darwin drew his wonderful store of facts has been some forty 

 years untouched. Speak to professional zoologists of any 

 breeder's matter, and how many will not intimate to you 

 politely that fanciers are unscientific persons, and their 

 concerns beneath notice? For the concrete in evolution we 



are offered the abstract. Our philosophers debate with great 

 fluency whether between imaginary races sterility could 

 grow up by an imaginary Selection ; whether Selection work- 

 ing upon hypothetical materials could produce sexual 

 differentiation ; how under a system of Natural Selection 

 bodily symmetry may have been impressed on formless proto- 

 plasm — that monstrous figment of the mind, fit starting- 

 point for such discussions. But by a physiological irony 

 enthusiasm for these topics is sometimes fully correlated 

 with indifference even to the classical illustrations ; and for 

 many whose minds are attracted bv the abstract problem of 

 inter-racial sterility there are few who can name for certain 

 ten cases in which it has been already observed. 



And yet in the natural world, in the collecting-box, the 

 seed-bed, the poultry-yard, the places w'here variation, 

 heredity, selection may be seen in operation and their 

 properties tested, answers to these questions meet us at 

 every turn — fragmentary answers, it is true, but each direct 

 to the point. For if anyone will stoop to examine Nature 

 in those humble places, will do a few days' weeding, prick 

 out some rows of cabbages, feed up a few score of any 

 variable larva, he will not wait long before he learns the 

 truth about variation. If he go further and breed two or 

 three generations of almost any controllable form, he will 

 obtain immediately facts as to the course of heredity which 

 obviate the need for much laborious imagining. If strictly 

 trained, with faith in the omnipotence of selection, he will 

 not proceed far before he encounters disquieting facts. 

 Upon whatever character the attention be fixed, whether 

 size, number, form of the whole or of the parts, proportion, 

 distribution of differentiation, sexual characters, fertility, 

 precocity or lateness, colour, susceptibility to cold or to 

 disease — in short, all the kinds of characters which we think 

 of as best exemplifying specific difference — we are certain 

 to find illustrations of the occurrence of departures from 

 normality, presenting exactly the same definiteness elsewhere 

 characteristic of normality itself. ."Vgain and again the 

 circumstances of their occurrence render it impossible to 

 suppose that these striking differences are the product of 

 continued selection, or, indeed, that they represent the results 

 of a gradual transformation of any kind. Whenever by any 

 collocation of favouring circumstances such definite novelties 

 possess a superior viability, supplanting their " normal 

 relatives, it is obvious that nevi? types will be created. 



The earliest statement of this simple inference is, I believe, 

 that of Marchant,' who in I7iq, commenting on certain 

 plants of Mercurialis with laciniated and hair-like leaves, 

 which for a time established themselves in his garden, 

 suggested that species may arise in like manner. Though 

 the same conclusion has appeared inevitable to many, in- 

 cluding authorities of very diverse experience, such as 

 Huxley, Virchow, F. Galton, it has been strenuously resisted 

 by the bulk of scientific opinion, especially in England. 

 Lately, however, the belief in Mutation, as De Vries has 

 taught us to call it, has made notable progress," owing to 

 the publication of his splendid collection of observations and 

 experiments, which must surely carry conviction of the 

 reality and abundance of Mutation to the minds of all whose 

 judgments can be affected by evidence. 



That the dread test of Natural Selection must be passed 

 bv every aspirant to existence, however brief, is a truism 

 which needs no special proof. Those who find satisfaction 

 in demonstrations of the obvious may amply indulge them- 

 selves by starting various sorts of some annual, say French 

 poppy, in a garden, letting them run to seed, and noticing 

 in a few years how many of the finer sorts are represented ; 

 or by sowing an equal number of seeds taken from several 

 varieties of carnation, lettuce, or auricula, and seeing in 

 what proportions the fine kinds survive in competition with 

 the common. 



Selection is a true phenomenon ; but its function is to 

 select, not to create. Many a white-edged poppy may have 

 germinated and perished before Mr. Wilks saved the 



1 Marchant, Mfm. Ac. roy. ties Kci. for 1719; 1721, p 59, Pis. 6-7. I 

 o»e this reference to Coutagne, " L'hiire'ditS chez les vers \%ok" {Bull, 

 sci. Fr. Belg. 1902). 



- This progr»»ss threatens to be rapid indeed. Since these lines were 

 written Prof. Huhrecht, in an admirable exposition (/'<'/. Sci. Monhly, 

 July, iQ'54)of De Vries' " Mutations-theorie," has even blamed me for having 

 ten years ago attached any importance to continuous variation. Neverthe- 

 less, when the unit of seEregation is small, something mistakablv like 

 continuous evolution mun 'urely exist. (Cp. Johannsen, " Ueb. Erblich- 

 keit in Populationen und in reinen Linien," 1903 ) 



NO. 181 7, VOL. 70] 



