IV.] THE MEASURE OF A SPECIES. Ill 



tained even by his most devoted adherents, he declared 

 that "one new variety' raised by man will be a more im- 

 portant 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 as a i)roof 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 bj^ quite subordinate characters." It 

 is impossible, however, actually to determine whether 

 one has a species in hand by applying a definition. One 

 must show that his new type — if it is a plant — has 

 botanical characters as well marked as similar accepted 

 species have, and these chai-acters must show, as a 

 whole, a general tendency towards permanency when 

 the plant is normally propagated by seeds. He must 

 measure his type by the rule of accepted botanical 

 practice. If the same plant were found wild, so that all 

 prejudice were removed, would the botanist unhes- 

 itatingly describe it as a new species? If yes, then we 

 would say that a new species had been <3reated under 



