84 



SCIENCE. 



[N. S. Vol. XXIV. No. 603. 



that " The mutation took place at once. * * * 

 No intermediate steps were observed. * * * 

 Not a single flower on the mutated plant re- 

 verted to the previous type." 



" According to degree of development at 

 the time of their first appearance they [varia- 

 tions] may be designated ordinary individual 

 variations, or sport variations. This is an old 

 story." ^' Exactly! The new story is de 

 Vries's very careful distinction between dif- 

 ferent kinds of sports. 



And when one reads that " his [de Vries's] 

 studies of plants have been mainly with spe- 

 cies as modified by man rather than with spe- 

 cies in a state of nature," ^^ one can not help 

 wondering if lectures II., XII., XVI., XX. 

 and XXIII. have been read at all. 



And again when it is stated that " As a mat- 

 ter of fact, subspecies in nature do not occupy 

 the same ground with the parent form, but 

 an adjacent area," one can only wonder why 

 a statement that may be quite true of a given 

 group of animals (e. g., birds), is made so 

 general as to include the entire plant king- 

 dom. In what sense, we may ask, is the term 

 subspecies used ? If by it is meant geographic 

 variety,"' then, of course, groups that do not 

 occupy the same region do not occupy the 

 same region. But the term is not used in this 

 sense in systematic botany. 



And if the mutation theory seems to any 

 one 'burdened' 'with the additional require- 

 ment that in giving off new forms the old is 

 not altered,' relief will come to him by in- 

 dulging in a little pedigree-culture experi- 

 mentation, and then digesting what ' Species 

 and Varieties ' has to say about the destruction 

 of the xinfit and the survival of the fittest 

 (elementary) species in ' intra-specific selec- 

 tion.' '" 



Can it be possible that, after reading ' Spe- 

 cies and Varieties ' and the larger German 

 work, the only source of an adequate explana- 

 tion of interspecific gaps is unlimited and 



^ Merriam, I. c, p. 245. 

 =^ Merriam, I. c, p. 247. 

 ^ Cf. the map, p. 256. 



^ ' Species and Varieties,' pp. 741, 744, 749, 

 75], 800, 801, 802, 805, 825. 



favorable field experience, and unlimited ex- 

 perience in handling specimens, etc. ? " 



" Inasmuch as sudden or sport variations 

 are exceedingly rare^ while slight variations 

 are exceedingly common, does it not follow 

 that the v^-st majority of species must orig- 

 inate from slight variations ? " ^' Possibly, if 

 it can be shown that the origination of new 

 species is an exceedingly common affair, and 

 a matter of frequent observation. So far as 

 the records show, no one, up to the time of 

 de Vries, had ever knowingly observed the 

 origin of a new species or natural variety. 



And when we read that " One might spend 

 a lifetime in studying animals and plants in 

 the interior of almost any of the faunal [and 

 ' floral,' we suppose is to be understood] areas 

 without encountering transitional forms or 

 intergrades," ^^ it almost seems as though we 

 were reading de Vries. The mutation theory 

 not only offers a possible explanation of this 

 fact, but would even lead one to expect such a 

 condition. 



Some ten years before the publication of 

 ' Species and Varieties ' Bateson inquired," 

 " Is it not then possible that the discontinuity 

 of species may be a consequence and expres- 

 sion of the discontinuity of variation ? " and 

 then added: 



Upon the received hypothesis it is supposed 

 that variation is continuous and that the discon- 

 tinuity of species results from the operation of 

 selection. For reasons given above (pp. 15 and 

 16) there is an almost fatal objection in the 

 way of this belief, and it can not be supposed that 

 all variation is continuous and also that the dis- 

 continuity of species is the result of selection. 

 With evidence of the discontinuity of variation 

 this difficulty would be removed. 



It will be noted that it is impossible to sup- 

 pose that the perfection of a variety, discontin- 



" Merriam, I. c, p. 256. 



^ Ignoring again the continuous sporting of 

 ' ever-sporting varieties,' and the distinctions be- 

 tween different kinds of sports. 



^ In the northern states white people are more 

 common than black. Therefore, all the people in 

 the northern states have originated from the 

 whites. Q. E. D. 



^Merriam, I. c, p. 256. 



^^ ' Materials for the Study of Variation,' p. 62. 



