REMARKS UPON THE DISTRIBUTION OF ANIMALS AND PLANTS. 57 1 



giving them support and warmth, and power to resist the fierce winds 

 which frequent these regions. Even the firs at the heads of the ravines 

 do the same thing, and, sometimes, where they grow thick together, after 

 rising two or three feet above the rocks, they spread out with a flat sur- 

 face, following the general slope of the ravine, and become so thickly in- 

 terwoven that one with care may walk quite a distance on their surface, 

 as upon a lawn, — yet if he do chance to slip through a treacherous open- 

 ing into the apartments beneath, if will be some time, — if not longer, as 

 I have found to my cost, — before he gets out again. 



Another point of great interest in the study of our mountain flora is 

 the large ratio of species common to it and Europe. Confining our 

 inquiries to the strictly alpine plants, forty-two of fifty-three, or sev- 

 enty-nine per cent, are common to both countries. This fact lends 

 countenance to the hypothesis that the two countries were formerly 

 much more intimately connected by means of a mountain chain than 

 they are at present. I am not aware what the ratio of species common 

 to the European and American floras as a whole is, but, remembering 

 that in the inquiry we must confine ourselves to indigenous plants exclu- 

 sively, it must be much less than twenty per cent. The disparity is from 

 any point of view quite remarkable, and its cause worthy close investi- 

 gation. 



List of Plants found i?i New Hamfshirc only on Alpine Summits. Those 

 found also in Europe are marked Eu; those marked with an asterisk (*) 

 were regarded by Asa Gray in 1856 as sub-alpine. 



Cardamine bellidifolia [Eu.] »Arnica mollis. 



Viola palustris [Eu.] Nabalus nanus. 



Silene acaulis [Eu.] N. Boottii. 



*Arenaria Groenlandica. *Vaccinium uliginosum [Eu.] 



Dryas integrifolia [Eu.] V. casspitosum. 



*Geum radiatum ; var. Peckii. Arctostaphylos alpina [Eu.] 



Sibbaldia procumbens [Eu.] Cassiope hypnoides [Eu.] 



Potentilla frigida [Eu.] Phyllodoce taxifolia [Eu.] 



Saxifraga rivularis [Eu.] Rhododendron Lapponicura [Eu.] 



Epilobium alpinum ; var. majus [Eu.] Loiseleuria procumbens [Eu.] 



*Solidago Virga-aurea ; var. alpina [Eu.] Veronica alpina [Eu.] 



Gnaphalium supinum [Eu.] Castilleia pallida [Eu.] 



