128 DR. D. LYALL ON THE BOTANY 
animals to be found in the forest on the line of march from the 
Chilukweyuk prairie, near the Fraser River, to the summit of the 
mountains; on account of which, a great proportion of the loads 
carried by horses and mules travelling this way must necessarily 
consist of grain for themselves. The only exception to this dearth 
of fodder is that near the Chilukweyuk Lake, which is at an alti- 
tude of 2052 feet above the sea-level, are some wet and swampy 
green spots, of small extent and destitute of trees. These are 
called ‘ wet prairies,’ and are covered chiefly with Gramines, Cype- 
racee, and Equisetacez, all of very luxuriant growth, and in suffi- 
cient quantity to feed a small number of animals, which greedily 
devour the latter especially, in spite of their siliceous coats. In 
winter, at times when the grass is deeply covered with snow, the 
Equisetaceze, growing under the fringe of trees and bushes border- 
ing the streams, form the principal food of such horses and mules 
as are unfortunate enough to have to trust entirely to nature for 
their supplies. As soon as the eastern slope of the Cascades is 
attained, all diffieulty about fodder for animals ceases, and parties 
may travel from thence to the Rocky Mountains without grain 
for their beasts of burden. At the same time, with a large orga- 
nized party like ours, where the mules were kept constantly on 
the move as long as the ground could be travelled over for snow, 
there is a short part of the route, between Sinyakwateen on the 
Pend Oreille River, and Chelemta on the Kootenay, where, on 
account of the comparative scarcity of grass, especially in autumn, 
it was considered advisable to pack a certain quantity of grain for 
the animals, in order to preserve them in full strength and vigour. 
Eastward from the valley of the Similkameen the country is 
generally grassy, with hills of moderate elevation, for a distance 
of sixty or seventy miles. At the point where the Nehoialpitq 
River bends suddenly to the southward to join the Columbia, & 
mountainous region commences. Indeed, from this, all the way to 
the Rocky Mountains, along the 49th parallel, there is nothing 
but a succession of steep mountain-ranges, with some narrow val- 
leys and ravines between, and the country altogether is so rugged, 
that any traveller proceeding from the Similkameen to the Bound- 
ary Pass in the Rocky Mountains must necessarily go as far south 
as the Spokan valley, in about lat. 47? 50' N., to enable him to 
aecomplish his object. 
To return to the west side of the Cascade Mountains: the work 
there having been finished as far as Roche River, in the heart of 
the range, it was found necessary, in eonsequence of the difficulty 
