78 
of the region he is treating. He must not let the political 
boundaries mislead him to draw corresponding division lines 
between his phytogeographical provinces or districts. Аз far 
as the Rocky Mountains are concerned, Professor Harshberger 
has committed two serious errors in this way: (1) He has drawn 
the line between the northern Rockies and the southern Rockies 
to correspond to the international boundary between Canada 
and the United States. (2) He has, at least in one part of his 
book, included the whole of New Mexico and Arizona in the 
Rocky Mountain Region. 
On page 546, Professor Harshbergher divides the Rocky 
Mountain Region into two districts: the Northern or Dominion 
District and the Southern or Park Mountain District, together 
with an eastern outlobe, the Black Hills Territory. Anyone 
who is well acquainted with the flora of the Rockies knows that 
nearly all the plants characteristic of the Canadian Rockies 
are also found in western Montana and northern Idaho. All the 
forest trees of the Canadian Rockies, the Gold Range and the 
Selkirks are also found, as far as I know, in the Bitter Root 
Mountains or in the Flathead and the Coeur d'Alene valleys. 
In fact, the northern Rocky Mountains, from a botanical stand- 
point, extend south to northern Wyoming, although many plants 
characteristic of the Selkirks and the Bitter Root Mountains 
are lacking. The Wind River Mountains may be regarded as 
the most southerly extension thereof. The southern Rockies, 
which may properly be called the Park Mountain District, do 
not extend farther north than to the Laramie Mountains of 
southern Wyoming. Between these and the Wind River Moun- 
tains is an opening, where the plains practically break through. 
Several of the forest trees of the southern Rockies are not found 
north of this break, as for instance, Picea pungens, Abies concolor, 
Pinus aristata and P. edulis, Sabina monosperma and rarely 
S. utahensis, nor any of the scrub-oaks. Of course Larix occi- 
dentalis, L. Lyallii, Abies grandis, Tsuga heterophylla, T. Merten- 
siana, Picea albertiana, Pinus monticola, Thuja plicata, Sabina 
prostrata, and Taxus brevifolia of the Canadian Rockies are not 
found in Colorado, but are found in western Montana and north- 
ern Idaho, and some of them extend into northern Wyoming. 
UTE E - 
SEPTA АТЫ ТЫ к FF 
Кашы ЖЕТЕ се ыа а а а NR 
