330 THE CANADIAN NATURALIST. [Sept, 



compared with anything which they had in the east. Hitherto 

 it had been mostly inacces8ible, but now that railways were mak- 

 ing it accessible, further exploration would reveal its flora and 

 thus it could be compared with the Alpine flora of Europe. The 

 woody belt of coniferous trees began at an average elevation of 

 six thousand feet. Its densest growth was at between seven 

 and nine thousand feet elevation, and its termination was at an 

 average height of eleven thousand three hundred feet. The 

 growth was most dense and varied where there was the greatest 

 and most regular amount of aqueous precipitation. At still 

 higher elevations the actual limit of tree growth was determined 

 by conditions of temperature which satisfactorily explained the 

 peculiar features of vegetation there met with. This belt of 

 trees terminated with singular abruptness. The probable explana- 

 tion was that this timber line marked the extreme point of mini- 

 mum winter temperature below which no phoenogamous vegetation 

 could exist. After alluding to the meteorological conditions of 

 the region, the paper went on to point out the peculiar dwarfed 

 tree growth scattered occasionally above the timber line. It was 

 on the most open exposures above that the Alpine flora was most 

 diversified and attractive, presenting from June to September a 

 succession of colors most attractive to the eye of the naturalist. 

 Out of one hundred and forty-two species, fifty-six were exclu- 

 sively confined to these Alpine exposures. The usual charac- 

 teristics of Alpine plants were a dwarfed habit of growth, late 

 period of flowering, and early seeding, the forms being exclu- 

 sively perennial. Of the thirty-four natural orders in the Alpine 

 flora, thirty one belong to the Phcenogamous plants, the remaining 

 three were of the higher order of Cryptogams. Of the latter, 

 ferns were represented by a single species not exclusively Alpine 

 (Cryptogramma acrosticlioides) . Mosses were more numerously 

 represented, but were still comparatively rare. Lichens were 

 most abundant and afforded the greatest number of species. The 

 superficial extent of these bare Alpine exposures in Colorado 

 Territory had been roughly estimated at from twelve hundred to 

 fifteen hundred square miles. After a brief allusion to the 

 fauna of the region, the paper stated that, when accessible, it 

 would doubtless afford a good site for summer pasturage, and 

 eventually yield choice dairy products, equalling those of the 

 Swiss Alps, and produce delicate fibrous tissues rivalling those of 

 the looms of Cashmere. As a summer resort it was unexcelled 



