No. 514] 



ARE SPECIES REALITIE 



605 



But we have progressed since Darwin, it may be said. 

 I hope we have a little. But have we or have we not pro- 

 gressed toward a conception of animate nature as a chaos 

 of such seething instability that distinctions are essen- 

 tially arbitrary and boundary lines between groups of 

 forms to be drawn only at the pleasure of the individual 

 with due reference to high authority and venerable tra- 

 dition? Until I read the luminous article of the leader of 

 the aforesaid symposium I had certainly thought not. I 

 had been led to believe that we were progressing, all in 

 all, in the opposite direction. 



I lay claim to no particular knowledge of things bo- 

 tanical. I know there are certain genera of plants where 

 specific and varietal characters are much confused and 

 very possibly undifferentiated. Definite species may in 

 such cases be very possibly undeveloped or degenerate, 

 and therefore non-existent. I remember that in niy her- 

 barium days I wondered that botanists would carry their 

 system through, whether or no, and describe species 

 where they themselves plainly doubted their reality. It 

 seemed to me this was following the final advice of the 

 Devil in Faust and building systems of words without 

 meaning. I little dreamed, however, that they would ever 

 go so far as to defend the whole Mephistophelean hypoth- 

 esis of an essentially arbitrary system of words without 

 objective validity. 



Surely some botanists are feeling their way far from 

 this conclusion, when, as for example De Vries, after half 

 a life time of experimentation, formulates a theory of 

 species which is not only that of a real thing in nature, but 

 approaches in definiteness and demarcation to the con- 

 ception of a chemical compound. Species, for De Vries, 

 are almost chemical compounds. Are chemical com- 

 pounds—chemical species, so to speak— are they realities, 

 or are they too concepts only? 



When I began this paper I had in mind to employ the 

 majority of mv space in the presentation and analysis of 

 facts concerning a few species with which I have worked 

 personally and which have been chosen with definite re- 



