188 



Professor Drude, who brought an aneroid barometer with him to 

 America. 



Deciduous Forest Formation. — The forest at the base of 

 Mt. Tahawus along the Au Sable River and about the Au Sable 

 lakes, according to my observations, consists of the following 

 dominant species : * Bctiila Intca, Fagus aviericana, Acer sac- 

 clianiui, Tsiiga canadensis, Thuja occidentalis, Pinus Strobns, 

 Abies balsainca and Betula papyrifera (the Fagiis-Accr-BeUda 

 fades), while as secondary trees grow Acer rubrnui, Acer pcnn- 

 sylvanintvi, Popnliis trevuiloides, Sorbns americana and beneath 

 the latter Vibnrnttin aliiifoliiim, Ritbus odoratus and ]lburu?tin 

 cassiiioides. Such are called in Adirondack phraseology, hard- 

 wood lands, which occupy in general the elevated flats and slopes 

 where the deciduous-leaved trees are the characteristic species. 

 Acer sacchariivi, Betula hi tea and Fagus americaua attain their 

 best development on these lands, while Tsuga canadensis is of 

 inferior quality to that found on the moister soil of lower ground. f 

 Along the Au Sable River, near its source, in a deep gorge were 

 found in 2iSsoc\dii\oy\ Acer sacchanun, Tsuga canadensis diud Betula 

 lutea as the dominant species, while the beech, Fagus aviericana, 

 seems to have a crown which never rises quite above that of 

 the trees mentioned {Tsuga-Fagus facies). The herbaceous 

 plants of the forest floor are Viola rotuiidifolia, Tiarella cordi- 

 folia, Medeola virginica. Mite Julia re pens, Unifoliuni canadcnse, 

 Clintonia borealis, Trillium utidulatunt, Streptopus antplexifolius, 

 Pyrola chlorantha, Oxalis Acetosclla, Aralia raceviosa, Dalibarda 

 repens and Lycopodiuni luciduluui. Taxus canadensis forms a 

 .secondary element in the Ts?iga-J'agus facies. Polypodiuni 7'ul- 

 gare forms mats in undisputed possession of the tops of boulders, 

 while the rock sides are distinguished by the presence of species 

 of Untbilicaria. Dryopteris noveboracensis forms extensive patches 

 in the deep recesses of the forest. 



The siiores of lower Au Sable Lake, which are mountainous 

 and stcej), arc covered with Betula papyrifera a.ssociated with 

 Abies balsantea and Populus trcjuuloides, while near the u])per end 



* Names accorfling to Hritlon's Manual, igoi. 



t I'inchot, (i. The .Xciiroiulack Spruce, 12. 1S9.S. 



