304 



NATURE 



[May 12, 1910 



independent of selection" (p. 90); "by natural selec- 

 tion species are not created [no one ever thought they 

 were], but eliminated " (p. 199). Selection " now has 

 served its time as an argument for the ' Theory of 

 Descent ' " (p. 29). It was, indeed, finally disposed of 

 by Lord Salisbury (p. 70), a fact which would have 

 more weight if he had not ludicrously misappre- 

 hended the Darwinian theory. 



The utility of specific characters (p. 65) and adapta- 

 tion necessarily go by the board as well. Desert 

 plants are not adapted to desert life. "They endure 

 the desert, but only with difficulty " (" Plant Breed- 

 ing," p. 350) ; " the spurs of the orchids . . . have not 

 been originated in the way in which plants are now 

 using them " {I.e., p. 352). It must be admitted that 

 all this is perfectly consistent, and foilows logically 

 from the conception of the species as an arbitrary re- 

 sult, "independent of the environment," and for which 

 "we can as yet assign no cause" (p. 130). This 

 makes a pretty complete sweep of the Darwinian 

 theory, and practically takes us back to the position 

 of Linnaeus, who was content to suppose that species 

 were created. It must, however, be put to de Vries's 

 credit that he makes an heroic attempt to save Dar- 

 win himself from the wreck by claiming him as at 

 heart a mutationist (p. 87) who " only by the pres- 

 sure of criticism " (p. 39) gave up the true faith. 

 There is a little irony in the fact that, as the critic was 

 apparently Fleeming Jenkin (p. 37), the mischief was 

 the work of a physicist. The attempt, though gener- 

 ous, is scarcely convincing, and so Darwin goes, and 

 with him goes the splendid and fertile field of biologi- 

 cal research for which he opened to us the door. Its 

 place is taken by the procession of arbitrary mutants 

 which have nothing to tell us because they have 

 nothing to say. It is a rather dreary outlook, only 

 mitigated by the "hope that we may be able to gain 

 some control over the formation of species " (p. i86). 

 Yet when I turn to Darwin and read "We have no 

 evidence of the appearance, or at least of the continued 

 procreation, under nature, of abrupt modifications 

 of structure" ("Variation," ii., p. 414), I pluck up 

 a little conviction of something that seems more full- 

 bodied than a mere echo of Fleeming Jenkin. It may 

 be remarked, however, that the celebrated argument 

 of the latter has never been refuted. 



I do not know whether to take comfort from the 

 fact that if Darwin fares badly, Lamarck fares worse. 



" Specific characters are never ' acquired ' ; and there 

 is no need for taking * acquired characters ' into con- 

 sideration in the whole domain of comparative biology 

 and the theory of descent " (pp. 130-1). 



That gets a troublesome question out of the way, at 

 any rate. To finish clearing the ground, a last 

 dictum : — " No theory of the origin of species can have 

 any bearing at all on this subject" [sociology] (p. 

 159). " Man is immutable albeit highly variable " (p. 

 156), a reservation with little satisfaction, as de Vries 

 will allow no stability to racial variation. 



It may be asked, on what are these sweeping con- 

 clusions based? Bateson inferred the discontinuity of 

 variation from the observed discontinuity of species. 

 De Vries apparently does not accept this, but for once 

 NO. 21 15, VOL. 83] 



adopts the obvious Darwinian explanation, "Sub- 

 species become species by the extinction of intermediate 

 forms " (p. 186). His own theory is based on the 

 prolonged study of a single species of unknown and 

 suspect history. It is, perhaps, one of the most remark- 

 able cases in science of generalisation from a single 

 instance, and that highly dubious. 



He commences the account of his experimental 

 work by remarking (p. 217) : — ■ 



"The chief obstacle in the way of . . . investigating 

 the origin of species is our complete ignorance of 

 the conditions under which the process takes place." 

 To test it, he "brought over one hundred species into 

 cultivation " from the neighbourhood of Amsterdam. 

 " Only one of these turned out to be what I really 

 wanted." He does not tell us in what respect they 

 failed, but concludes that mutability Occurs "relatively 

 rarely." It seems, therefore, to be open to the same 

 kind of objection as has been urged against natural 

 selection, that it "will generally act," as Darwin said., 

 "very slowly, only at long intervals of time" 

 (" Origin," sixth edition, p. 85). I think it is clear 

 that what baffled de Vries was specific stability. It 

 takes a somewhat prolonged subjection to cultural, i.e. 

 changed, conditions to break this down. I have given 

 numerous instances in these pages of extremely stable 

 species which ultimately broke down. I have watched 

 the process at Kew in Primula obconica, which now 

 produces flowers two inches across. The process was 

 described by Vilmorin half a century ago : — "The fixed 

 character of the species being once broken, the desired 

 variation will sooner or later appear" (Darwin, 

 "Variation," ii., p. 262). I cannot doubt, therefore» 

 that if de Vries had had patience, every one of his 

 hundred species would have become plastic in his 

 hands. 



He, then, has been obliged to rest his theory on a 

 single case, that of CEnothera lamarckiana. There is 

 no evidence that this is a "natural species." It made 

 its appearance in the Paris Jardin des Plantes, and, 

 as pointed out by Lock and Boulenger, de Vries's 

 results are open to the interpretation of being simply_ 

 due to " Mendelian disjunction." 



But, waiving this point, there is a graver difficulty, 

 De Vries insists (p. 130) that his mutations are 

 "independent of the environment." A moment's re 

 flection will show the disadvantage under which his 

 theory rests in this respect compared with that of 

 Darwin, which provides a means of automatic and 

 continuous equilibrium, and remorselessly eliminate* 

 whatever fails to adjust itself to it. De Vries admits, 

 (p. 199) that his mutations must submit themselves t<» 

 selection ; but they are so handicapped at the starts 

 that they can rarely have much chance, and this isi 

 confirmed by the inability of sports to hold 

 their own in nature. Even CEnothera lamarckiana^ 

 whatever it may do under cultivation, does not appear 

 to be able to produce permanent varieties under 

 natural conditions. 



Two other lines of argument require brief examina-* 

 tion. De Vries points to the familiar little crucifer,. 

 Draba verna, whiclv is now in fiower everywhere, as. 

 a case of natural mutation. Jordan collected from 



