322 The Botanical Gazette. [October, 
inherited faculty) made them follow trails over the lowest and - 
best divides between streams. 
When following large herds in Nebraska, Kansas, Colorado, 
Indian Nation and Texas, we have seen these trails in soft 
rich ground worn down five or six feet deep, thirty or forty 
feet wide, as well defined as a graded wagon road. 
We have spoken of their migration only in a sense re- 
stricted to our personal knowledge in the region we have 
already described. Yet from the best information we can get 
we find that this same yearly change of locality occurred in 
northern Idaho, Montana and Dakota, and north of the Black 
Hills, not so much from scarcity of forage, as the necessity of 
shelter from the winter snows and blizzards of the upper Mis- 
souri and Yellowstone prairies; while in British America, ac- 
cording to the accounts of Franklin, Richardson, and also 
Messrs. Milton and Cheadle for the Saskatchewan and upper 
Athabaska valleys, the buffalo were driven by snow and intense 
cold from the open country into the timbered valleys, and 
forests west of the open plains and in the Athabaska region. 
In the spring the general movement of the buffalo was north 
into Nebraska, Colorado, Wyoming and Kansas across the 
d pe 
generally or 
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