Central Part of British North America. 229 
through a country that is on the whole heavily timbered, but 
the quality of the forest varies a good deal with the soil and 
elevation. Thus, round Thunder Bay, on Lake Superior, the 
ash, elm, maple, and cedar, with a rich undergrowth of rosa- 
ceous shrubs, are met with in addition to the white spruce, 
larch, pines of several species, birch and poplars; but on the 
high lands round Dog Lake, elevated 1500 feet above the sea, 
the forest consists almost entirely of the latter trees. In 
descending to Rainy Lake, the more valuable timber reap- 
pears, wherever the soil is favourable to its growth, and such 
trees as Pinus resinosa, P. Strobus, and Cupressus thyoides, 
sometimes reach a large size. From Rainy Lake to the Red 
River Settlement, the forest becomes more varied and richer 
in its character, comprising elms, oaks, ash, basswood, (Tilia 
americana), beech, and ironwood (Ostrya virginica), but still 
with a large admixture of Conifers. In this district the under- 
growth is very luxuriant, many of the shrubs of the Northern 
States occurring plentifully. On the borders of the lakes and 
rivers, the Indian rice (Zizania aquatica) is abundant, the 
grain of which, along with fish, forms the principal food of the 
Salteau aan 
In proceeding due west fron the Red River Settlement, the 
Prairie country is at once entered upon, being bounded to the 
north by the wooded country, the limit of which nearly fol- 
lows the isothermal mean of 41° in a northwest direction, 
until it reaches the 109th meridian in Lat. 53° N.,* when it 
sweeps again to the south-west to intersect the Rocky Moun- 
tain chain in Lat. 51°. The country to the north of the 49th 
parallel, and up to the 55th, which was the region examined, is 
thus boldly marked into two districts by the presence or absence 
of timber. A third district must however be also considered, 
forming a belt dividing the forests from the true plains, and 
which at one time was itself forest-land, but having been cleared 
by the successive devastations of prairie fires, 1t now combines 
the advantages of both, having extensive ranges of open land 
like the prairies, which possess the rich vegetable mould, and 
* It is probable that this isothermal, as generally represented, does not 
sweep enough to the south after crossing the Rocky Mountains from the west 
when passing through Long. 114° to 96°. 
NEW SERIES.—VOL. XIy. NO, 11.—ocT. 1861. 2G 
