II) 



THE FERN BULLETIN 



wherever there are congenial dwelling- places. 



There still remains, however, the case of the harts- 

 tongue, which up to the present has been the most 

 puzzling- of any in our flora. Found only in a limited 

 region in Central New York, a still more limited sta- 

 tion in Tennessee and a few rather more extensive lo- 

 calities in Canada, -it does not occur again for three 

 thousand miles. The most plausible explanation of 

 such distribution is that at one time the fern had a 

 much wider distribution, and has since died out at the 

 intervening points. 



None of these explanations, however, seem to fit 

 the case of Asplenium alternans. In all the other 

 species mentioned, the specimens have naturally a 

 wide distribution and this of itself makes it easy to 

 assume a further extension of their range. But As- 

 plenium alternans is not in this class. .It appears, in- 

 deed, to be rather common in the Himalayan region. 

 Hope who gives its distribution as from Afghanistan 

 and Northern India to Assam, at elevations of from 

 4,000 to 8,000 feet, marks it "common" or "profuse" 

 in several stations, but the fact remains that the fern 

 has not the general distribution of the other ferns, 

 whose widely separated colonies have been mentioned 

 and it does not seem at all likely to the writer that the 

 ferns found growing in one small locality, in Arizona, 

 in fact, in a small portion of a single glen, are the 

 remnants of a once more widely distributed group on 

 this side of our planet. 



There still remains two other theories that might 

 account for its presence in our Southwest. A certain 

 school of botanists have frequently favored the idea of 

 a multiple origin for various species. In this way they 

 account for species that are common to both sides of 

 the Atlantic or common to our Atlantic seaboard and 



