98 MASSACHUSETTS HORTICULTURAL SOCIETY. 



The intermediate and variable forms are perplexities to one who 

 attempts to describe species as so many entities which have 

 distinct and personal attributes. So the garden has always been 

 the bugbear of the botanist. Even our lamented Asa Gray 

 declared that the modern garden roses'were "too much mixed by 

 crossing and changed by variation to be subjects of botanical 

 study." He meant to say that the roses are too much modified to 

 allow of species-making. The despair of systematic botanists 

 is the proof of evolution ! 



I repeat that mere species-making, in the old or conventional 

 sense, is an incubus to the study of nature. One who now 

 describes a species should feel that he is simply describing a 

 variable and plastic group of individuals for mere convenience's 

 sake. He should not attempt to draw the boundary lines hard 

 and fast, nor should he be annoyed if he is obliged to modify his 

 description every year. This loose group may contain some forms 

 which seem to be aberrant to the idea which he has in mind ; and 

 it would seem as if he should be ready to call them new or 

 distinct species whenever, from whatever cause, they become so 

 much modified that it is convenient, for purposes of identification 

 and description, to separate them from the general type. Just as 

 soon as botanists come to feel that all so-called species of plants 

 are transitory and artificial groups, maintained for convenience in 

 the study of Nature, they will not ask whether they are modified 

 outside the garden or inside it, but will consider groups of equal 

 distinctness and permanence to be of equal value in the classifica- 

 tion of knowledge, wholly aside from the mere place of their 

 origin. At the present time, the garden fence is the only distinc- 

 tion between many accepted species and many disregarded ones. 

 The cultivation of man differs from the methods of nature only in 

 degree, not in kind ; and if man secures results sooner than 

 nature does it is only another and indubitable proof of the 

 evolution of organic forms. It is certainly a Avholly unscientific 

 attitude to demand that forms originating by one of nature's 

 methods are species, while similar forms originating by another 

 method are beneath notice. 



If species are not original entities in nature, then it is useless 

 to quarrel over the origination of them by experiment. All we 

 want to know, as a proof of evolution, is whether plants and 

 animals can become profoundly modified under different conditions, 

 and if these modifications tend to persist. Every man before me 



