EXPERIMENTAL EVOLUTION AMONGST PLANTS. ^9^ 



against the scheme to create a species before our eyes, but I am 

 simply stating what has been and is the insurmountable difficulty 

 in just this line of endeavor, — the inability of the experimenter 

 to satisfy the scientific world that he has really produced a 

 species ; for it is a singular thing that whilst all biologists now 

 agree in defining a species upon its tangible and present characters, 

 they nevertheless act, for the most part, upon the old notion that 

 a species must have its origin somewhere beyond the domain of 

 exact history. 



This notion that a species, to be a species, must have originated 

 in nature's garden and not in man's, has been left over to us from 

 the last geueration, — it is the inheritance of an acquired 

 character. John Ray, towards the close of the seventeenth cen- 

 tury, appears to have been the first to use the word species in its 

 technical natural-history sense, and the matter of origin was an 

 important factor in his conception of what a species is. Lin- 

 naeus's phrase is familiar: " We reckon as many species as there 

 were forms created in the beginning." Darwin elaborated the 

 new conception, — that a species is simply a congregation of 

 individuals which are more like each other than they are like any 

 other congregation, and with a freedom from prejudice which 

 is rarely attained even by his most devoted adherents, he declared 

 that "one new variety raised by man will be a more important 

 and interesting subject for study, than one more species added to 

 the infinitude of already recorded species." The old naturalists 

 threw the origin of the species back beyond known causes ; 

 Darwin endeavored to discover the " Origin of Species," and it is 

 significant that he set out without giving any definition of what a 

 species is. I have said this much for the purpose of showing that 

 it is important, when we demand that a new species be created aa 

 a proof of evolution, that we are ourselves open to conviction that 

 the thing can be done. 



I have said that no modern naturalist would define a species in 

 such terms that some horticultural types could be excluded, even 

 if he desired that they should be omitted. Haeckel's excellent 

 definition admits many of them. In his view, the word species 

 ' ' serves as the common designation of all individual animals or 

 plants, which are equal in all essential matters of form, and are 

 only distinguished by quite subordinate characters." It is impos- 

 sible, however, actually to determine whether one has a species in 



