ntry in which
they now found themselves was if possible more of a desert than that
they had just quitted. Even rabbits could not dwell in it, or the few
that were started could not be caught. The _artemisia_ was not in
sufficient plenty to make an inclosure with, and it would have been
hopeless to have attempted such a thing; as they might have spent days
without trapping a single hare. Now and again they were tantalised by
seeing the great sage cock, or, as naturalists call it, "cock of the
plains" (_Tetrao urophasianus_), but they could only hear the loud
"burr" of its wings, and watch it sail off to some distant point of the
desert plain. This bird is the largest of the grouse kind, though it is
neither a bird of handsome plumage, nor yet is it delicate in its flesh.
On the contrary, the flesh, from the nature of its food, which is the
berry of the wild wormwood, is both unsavoury and bitter. It would not
have deterred the appetites of our four trappers, could they have laid
their hands upon the bird, but without guns such a thing was out of the
question. For several days they sustained themselves on roots and
berries. Fortunately it was the season when these are ripe, and they
found here and there the prairie turnip (_Psoralea esculenta_), and in a
marsh which they had to cross they obtained a quantity of the celebrated
Kamas roots.

All these supplies, however, did not prove sufficient. They had still
four or five days' farther journey, and were beginning to fear they
would not get through it, for the country to be passed was a perfect
barren waste. At this crisis, however, a new source of subsistence
appeared to them, and in sufficient plenty to enable them to continue
their journey without fear of want. As if by magic, the plain upon
which they were travelling all at once become covered with large
crawling insects of a dark brown colour. These were the insects known
among the trappers as "prairie crickets," but from the description given
of them by the trappers the hunter-naturalist pronounced them to be
"locusts." They were of that species known in America as the "seventeen
years' locust" (_Cicada septemdecem_), so called because there is a
popular belief that they only appear in great swarms every seventeen
years. It is probable, however, that this periodical appearance is an
error, and that their coming at longer or shorter intervals depends upon
the heat of the climate, and many other circumstanc