CLASS I. MAMMALIA: ORDER 1. ROBENTIA. 
355 
an elevated position — usually the very top of a tree — stretch out their legs, thus expanding their 
flying-membranes, spread their tails, and launch forth witli a spring or jump, usually taking aim 
at the trunk of some tree at the distance of forty or fifty yards. They glide swift as an arrow, 
gradually descending, until, seeming to he near the earth, they suddenly turn upwards, and alight 
on the body of the tree to which their flight was directed. Some of them may be seen flying 
back to the same tree from which they started, again and again repeating this operation, and evi- 
dently enjoying the performance as a matter of sport. Others having alighted on one tree, ascend 
to its top and glide to another; again mounting and starting, and thus proceeding in a direct 
line, they will travel a quarter of a mile in an exceedingly short space of time. 
Such is the scene occurring every night, during the Avarm season, in a thousand places in our 
American forests. We — animals of the daylight — are apt to fancy that the whole world of ani- 
mated nature sympathizes with us, and that all go to their repose as we do, in the hours of dark- 
ness, forgetting that to innumerable species the day is the time of darkness and sleep, and night 
the season of light and activity and enjoyment. It is in the night that whole tribes of animals, 
foxes, Aveasels, martens, skunks, lynxes, wild-cats, cougars, — to say nothing of owls, goat-suckers, 
and the multitudinous race of moths, — Avake from their slumber and go joyously forth on their 
various adventures, whether of love, feast, or frolic. Whoever would comprehend the whole field 
of nature, must not be content to look merely upon the surface, and that by daylight: he must 
reflect upon what passes beyond the reach of sight, whether in the shadoAvs of night, or in the 
recesses of the earth; in the soil and the sod; in caves and rocks, and in the sea. 
The Oregon Flying-Squirrel, Pteromys Oregonensis^ is somewhat larger than the preceding, 
the length of the body being nearly seven inches. Its general color is brown above and white 
beneath. Its habits are little knoAvn ; but they are, doubtless, very similar to those of the pre- 
ceding species. It is found on the Rocky Mountains, in the region of the Columbia River, as well 
as Avest and north of that locality. 
The Severn River Flting-Squirrel, Pteromys Sahrinus^ is one-third larger than the P. 
volucella^ the body being eight inches in length ; its color above is a dull, yelloAvish gray, with 
irregular patches of a darker shade, and white, with a tinge of bufl", beneath. On the whole, it 
bears a considerable resemblance to the European flying-squirrel. It is common at Quebec and 
the vicinity, and along the shores of Lake Huron, A curious instance is recorded in which a 
brood of young squirrels of this species were kept in confinement for some months. The mother 
suckled her young ones by clinging with her fore-feet to the perch of the cage, letting her body 
hang down, Avhile the little ones stood on their hind-legs and tox)k their meal from her breast. 
This brood was procured by some laborers, Avho, in clearing a wood by setting it on fire, saw the 
mother carry them, one by one, from the burning trees, to a place of safety. When they took 
her, she Avas found to be singed. This good and devoted mother had three of her young ones 
killed by the rats, which got into the cage at night ; and she herself had one of her thighs 
broken, and a part of her flesh eaten from her body to the bone ; yet she was found in the morn- 
ing clinging to her little ones and trying to nurse them ! 
m The Ro CKY Mountain Flying-Squirrel, Pteromys Alpinus^ is still larger than the preceding, 
the body being eight and a half inches long; the general color is yellowish-brown, on the back; 
on the throat and belly, a grayish-Avhite. It is found in the thick pine woods of the Rocky 
Mountains, about latitude 42°. It is very shy, and seldom ventures from its retreat, except at 
night. It seems to be of a heavier mould than the other species, and its flying membrane is also 
of comparatively less size ; Avhence, it is inferred, that its power of supporting itself, in gliding 
through the air, is inferior to that of some other kinds. 
