10 LAKE SUPERIOR. 



action of heat. Thus, for instance, the blackish mica slate, with veins of 

 quartz, which so frequently occurs on our route of to-day is probably 

 clay slate, altered by intense heat, which has produced several varieties 

 of silicate of alumina. There is no clearly defined division between 

 these slates ; they pass without interruption from baked clay into 

 chloritic slates. In one place in the Connecticut valley we saw red sand- 

 stone, generally in a horizontal position, except where disturbed by trap. 

 Nearer Albany we passed through a region of highly metamorphic lime- 

 stone, belonging to the oldest geological deposits. We have also seen indi-, 

 cations of the Potsdam sandstone, one of the most ancient fossiliferous 

 rocks. 



" As to the vegetation, it is to be remarked in general, that the features 

 of a country are given principally by its plants. These mark the variety of 

 the soil, and its formation. The forests which we have seen to-day consist of 

 a great variety of plants, mingled together. We have seen no forests com- 

 posed of one species of tree. In the mountainous parts, indeed, certain 

 species predominate, but elsewhere several are found in almost equal pro- 

 portions. Among these are various pines ; the white and pitch pines, the 

 spruce, hemlock, red cedar, and a few larches. Then the Arnentacene, 

 viz., oaks, birches, chestnut, beech, poplar, and the platanus or button wood, 

 (which is in a sickly condition, probably from injury done to the young 

 wood by frosts,) hickories, elms, locust, ash, and maples, but the latter fewer 

 in number. The hickories never form forests. About Niagara we shall 

 find the beech abundant. Of shrubs, we have seen a great variety : e. g., 

 sumachs of several species, (whereas in Europe there is but one,) elder, 

 alder, cornus, viburnum, witch-hazel, willows, wild roses, and grapes. A 

 remarkable feature of the vegetation of this country is, the number of species 

 of grape, mostly useless for the manufacture of wine. Shrubs peculiar to 

 America, are the Kalmias ; viz., mountain-laurel and sheepsbane. In the 

 meadows are various grassy plants, carices, and ferns ; the latter in great 

 variety. These spots exhibit probably a condition analogous to that of the 

 Coal Period, in which the ferns, &c., prevailed. All the plants growing on 

 the roadsides are exotics, as are also all the cultivated plants and grasses. 

 Everywhere in the track of the white man we find European plants ; the 

 native weeds have disappeared before him like the Indian.* Even along the 

 railroads we find few indigenous species. For example, on the railroad 

 between Boston and Salem, although the ground is uncultivated, all the 

 plants along the track and in the ditches are foreign. From this circum- 



* Old Tocelyn says the Indians call the common plantain (Plantayo major,') " the 

 white man's foot." 



