228 Dr James Hector on the Physical Features of the 
lies within the British territory, and the alpine and subal- 
pine district of the Rocky Mountains. 
Until a thorough and critical analysis of the whole flora is 
accomplished, we cannot however expect much light to be 
thrown by the method of tabulation on the natural affinities 
which the floras of the different areas bear to one another ; 
and till then it is therefore safer, in adapting provisional 
geographical groups, to rely more on the nature of the forest 
growth and such evident characters that catch the eye of the 
traveller. Such an analysis has however been recently effected 
for the flora of the northern part of the continent in a highly 
philosophical memoir by Dr Hooker (‘‘ Outlines of the Distri- 
bution of Arctic Plants,” read before the Lin. Soc. of Lon- 
don, June 21, 1861). His work has yielded most important 
results, modifying the generally received opinion of the uni- 
formity of the Arctic flora throughout every longitude; and by 
tracing its distribution, he has found strong grounds for sup- 
porting the theory first promulgated by the late Edward 
Forbes, of a southern migration of northern types having taken 
place during the cold of the glacial epoch, and also of Dar- 
win’s view of the high antiquity of the Scandinavian Flora. - 
With regard to the northern flora of the American conti- 
nent, Hooker has modified the areas described by Richardson, 
in so far as not distinguishing between an Arctic and a Polar 
flora, but merely dividing the whole region into an “ Arctic 
West American Flora,” which extends from Behring’s Straits 
to M‘Kenzie’s River, and an “ Arctic East American Flora,” 
which extends from that river to Baffin’s Bay, but excludes 
Greenland, the flora of which he shows to belong to a Euro- 
pean and not to an American type.* 
Bearing in view the leading physical features of the coun- 
try which have already been alluded to, and to the general 
botanical divisions that have been quoted, I shall now follow 
the course of the expedition, and briefly sketch the features of 
the vegetation observed along the route. 
The canoe route from Lake Superior to Lake Winipeg, 
by which the spur of the eastern axis was crossed, passes 
* J am indebted to the kindness of Dr Hooker in letting me have an oppor- 
tunity of studying this valuable memoir while passing through the press, 
