July 20, 1906.] 



SCIENCE. 



85 



uously and suddenly occurring, is the result of 

 selection. * * * This consideration of course 

 touches only the part that selection may have 

 played in the first building up of the type and 

 does not affect the view that the perpetuation of 

 the type, once constituted, may have been achieved 

 by selection.^^ 



To say the least, the declaration that ' so 

 far as known,' the theory of the origin of spe- 

 cies by mutation is * not applicable in the case 

 of animals,' seems a rather arbitrary statement 

 in the face of the mass of contrary evidence 

 that exists in recent literature/^ 



Considering the volume of evidence in zool- 

 ogy^* that ' distinct and perfect varieties may 

 come into existence discontinuously,' the ques- 

 tion forces itself, ' may not the discontinuity 

 of species have had a similar origin ? ' At 

 least the strong "presumption is created that 

 the discontinuity of which species is an expres- 

 sion has its origin not in the environment," 

 which is continuous, " nor in any phenomenon 

 of adaptation, but in the intrinsic nature of 

 organisms themselves, manifested in original 

 discontinuity of variation." ^ 



By a strange chance the article by Dr. Ort- 

 mann, in Science for May 11, 1906, imme- 

 diately precedes one entitled ' Misrepresenta- 

 tions of Nature in Popular Magazines.' The 

 history of science furnishes all too many in- 

 stances of misinterpretations of scientific the- 

 ory in scientific magazines. We do not recall 

 an instance in which Darwinism (Darwin's 

 Darwinism) has been more twisted out of 

 shape than has the mutation theory in this 

 latest exposure of its ' fallacy.' It would be 

 interesting to know if the mutation theory 

 itself would meet with such an ' emphatic ' 

 and wholesale * condemnation ' as does this 

 misinterpretation of it. 



We are told that " de Vries claims that the 

 process of mutation forms new species, and 

 that individual mutations (mutants) are spe- 

 cies." The title of the English volume is 



^Bateson, I. c, p. 69. 



^E. g., Bateson, I. c, Vernon, 'Variation in 

 Animals and Plants.' 



^' Space forbids citation of specific illustrations. 

 '^Bateson, I. c, p. 567. 



' Species and Varieties, their Origin by Muta- 

 tion,' and one has to read only as far as the 

 ninth page to learn that the author intends 

 " to give a review of the facts obtained from 

 plants which go to prove the assertion that 

 species and varieties have originated by mu- 

 tation, and are at present not hnotun to orig- 

 inate in any other way," and on page 16 

 " Retrograde varieties and elementary [note 

 the adjective] species may hoth be seen to be 

 produced by sudden mutations." 



And why beat about the bush and say that 

 de Vries ' tries to show that mutations breed 

 true ' ? Why not frankly acknowledge the 

 fact, so magnificently established by twenty 

 odd years of painstaking experiment, and veri- 

 fied by other workers elsewhere, that the varia- 

 tions classed by de Vries as mutants do breed 

 true? 



If it is really true that de Vries ' does not 

 know what constitutes a species,' then, in- 

 deed, do we find our faith in his work thereby 

 increased. Who indeed, except the makers of 

 dictionaries, does ' know what constitutes a 

 species ' ? The author of the mutation theory 

 does know, however, that ' genera and species 

 are, at the present time, for a large part arti- 

 ficial, or stated more correctly, conventional 

 groups,' and that, 'every systematist is free 

 to delimit them in a wider or in a narrower 

 sense, according to his judgment.' 



Is it possible that one who can write, 

 " What distinguishes species^^ from ■v'^rieties 

 is the fact that the species is not connected 

 by intermediate or transitional forms with 

 the closely allied species," has ever come 

 into contact with a group like the hawthorns 

 {Crataegus), or Aster, or the violets in bot- 

 any, or the earwig (Forficula) in zoology? 

 Whether this distinction ' is the one made use 

 of exclusively (if possible)" by systematists, 

 botanists as well as zoologists,' is, we believe, 

 quite open to question. It was a considera- 

 tion of the earwigs (Forficula) and crab (Car- 

 cinus) that led Vernon to state: "It is obvi- 

 ous, indeed, that between two absolutely dis- 



" The meaning of the parenthesis is not clear. 

 ^' Meaning the systematic groups of specific 

 value. 



