﻿THE FERX BULLETIN 



125 



tion is that animals and plants vary, and we are in- 

 clined to look with suspicion on any scheme that would 

 do away with such variation. 



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In the "Smithsonian Miscellaneous Collections," 

 vol. 5, part 3, Carl Christiansen, author of ''Index 

 Filicum" has an article on "The American Ferns of the 

 group Dryopteris opposita contained in the U. S. Na- 

 tional Museum" which illustrates very interestingly 

 the nice distinctions that now subsist between the tropi- 

 cal species of ferns. Every little while we have a sus- 

 picion that some of the described new species are not 

 as important as the sounding names bestowed upon 

 them would indicate, but it is seldom that we rind an 

 account of them that so naively admits the question- 

 able validity of the so-called new species. AYe fear 

 Mr. Christiansen lacks the yankee ability to throw dust 

 in the eyes of his critics when proceeding to split up 

 tweedledee and tweedledum. For instance, of his 

 new species, Dryopteris columbiana he says: I now 

 prefer to refer here this number, determined previously, 

 by myself and Hieronymus as D. oil go car pa from 

 which it differs in its longer leaf and by the shorter 

 pubescence of the rachis. Nevertheless, I have some 

 doubt if my proposed species can be held distinct from 

 D. oligocarpa:" Here our author is too modest. In- 

 stead of having some doubts he ought to be dead sure 

 of it. A longer leaf and shorter pubescence does not 

 make a species. Of D. Musensis he says "The main dif- 

 ference from D. Columbiana is in the absence of long 

 setae on the veins above." And the author doubts if 

 Columbiana is in itself a good species! Another spe- 

 cies. D. Melanochlaena. based on a single leaf is dis- 

 tinguished from its nearest relative "by its coal-black 



