uttering their tiny barking, that
sounded like the squeak of a toy-dog. It is from this that they derive
the name of "prairie-dogs," for in nothing else do they resemble the
canine species. Like all marmots--and there are many different kinds--
they are innocent little creatures, and live upon grass, seeds, and
roots. They must eat very little; and indeed it is a puzzle to
naturalists how they sustain themselves. Their great "towns" near the
Rocky Mountains are generally in barren tracts, where there is but a
scanty herbage; and yet the inhabitants are never found more than half a
mile from their dwellings. How, then, do thousands of them subsist on
what little grass can grow in a pasture so circumscribed? This has not
been explained; nor is it known why they choose these barren tracts for
their dwelling-places, in preference to the more fertile prairies. All
these things await the study and observation of the historian of nature.

Basil was surprised to observe that the marmots were not alone the
occupants of their town. There were other creatures moving about of an
entirely different kind, and they also seemed to be perfectly at home.
There were white owls, about the size of pigeons, of a species he had
never seen before. These were the burrowing owls (_Strix cunicularia_),
differing altogether from their blind cousins of the night who dwell in
thick woods and old ruins. He saw these little owls gliding about on
silent wing, or standing erect upon the tops of the houses, at a
distance looking exactly like the marmots themselves.

Besides the marmots and owls there were other live creatures in sight.
There were small lizards scuttling about; and crawling among the mounds
was seen a hideous form--also of the lizard kind--the "horned frog"
(_Agama cornuta_). These creatures were new to Basil; and their ugly
earth-coloured bodies, their half-toad half-lizard shape, with the thorn
like protuberances, upon their back, shoulders, and head, inspired him
with disgust as he gazed upon them. He could see, too, the small
land-tortoise (_Cistuda_) squatting upon the ground, and peeping
cautiously out of its box-like shell. But there was another creature in
this community more fearful than all the rest. This was the _ground
rattle-snake_, which could be seen, coiled up, and basking in the sun,
or gliding among the mounds, as if searching for his prey. Basil
noticed that it was a different species from any of the ratt