212 
Physical Features of the Central Part of British North 
America, with Special Reference to its Botanical Physi- 
ognomy. By JAMES Hector, M.D., F.G.S., &e.* 
The following paper is intended as a sketch of the botani- 
cal results of a Government expedition which was sent out in 
the spring of 1857 to explore the British territories lying in 
the neighbourhood of the northern boundary line of the United 
States, and stretching westward from Lake Superior across 
the Rocky Mountains. The expedition was placed under the 
command of Captain Palliser, who had previously travelled 
among the Indians in the district of the Upper Missouri and 
Yellowstone Rivers. His party consisted of Lieutenant, now 
Captain Blackiston, R.A., who had charge of the magnetical 
observations; Mr Sullivan, as secretary and assistant-astro- 
nomer to Capt. Palliser; M. Bourgeau, a botanical collector 
whose name must be familiar to the members of this Society 
who have had occasion to consult the Herbarium; and the 
writer of this paper, who filled the post of surgeon and natu- 
ralist. The expedition was in the field for three years, and in 
that time examined and mapped a region embracing 33° of 
longitude, and in some places 5° of latitude. 
Physical Characters of the Area explored.—Commencing 
at Lake Superior, the route of the expedition for the first 600 
miles to Lake Winipeg, crossed over a spur which diverges 
to the south-west from an axis of crystalline rocks that 
runs from Canada to the Arctic Ocean in a north-west direc- 
tion, and known as the “Intermediate Primitive Belt?’ of 
Richardson, or the “ Laurentian Axis” of Logan. This 
belt of rocky country nowhere acquires a mountainous char- 
acter, but is throughout extremely rugged and traversed by 
innumerable watercourses, and by long narrow lakes. The 
greatest altitude passed over in this portion of the journey 
was 1000 feet above Lake Superior, or 1600 feet above the sea- 
level. The inequalities of surface, and the diversity in the 
nature and amount of soil, has given a greater degree of com- 
plexity to the flora of this district than we might expect from 
its other physical conditions. ‘The winter experienced in this 
* Read before the Botanical Society of Edinburgh, 13th June 1861. 
