These Sciuridæ have no wings and no capacity of flight; but their anterior and posterior limbs are connected on either side by a membrane, which is really nothing but a fold of skin, and which they extend by spreading out their paws so as to present to the air a considerable surface. By means of this kind of parachute, they can cross, by leaping from one tree to another, an extensive area. My space only permits me to allude to the Virginian Flying Squirrel (_Pteromys volucella_), and the Common Flying Squirrel (_Pteromys volans_). The former is about five inches long, with a tail four inches; of a subferruginous brown colour above, and a yellowish-white beneath; the edges of the flying membrane are of a deeper tint than the rest of the fur, contrasting with the white border of the under part. He is naturally of a gregarious disposition, and ten or twelve may be seen in company, flying from tree to tree. In case of need he can swim like other quadrupeds, and yet, on quitting the water, can resume his aërial motion. He feeds on fruits, nuts, and young leaves and twigs; is of an affectionate nature, and easily domesticated. The Common Flying Squirrel (_Pteromys volans_) belongs to the northernmost regions, and his favourite haunt is the pine and birch woods of Siberia. On the upper parts his colour is a pale gray, on the under a milky white. Measured from the nose to the tail, his length is six inches; and the tail, which is thickly furred and slightly flattened, is somewhat shorter than the body. He flies, or rather springs, through the agency of an expansile furry membrane, reaching, as I have stated, from the fore-feet to the hind. He builds his nest of the finest mosses in the hollows of the old forest trees; is a solitary animal emerging from his retreat only at the approach of the gloaming; feeds on young buds and catkins; and springs from one tree to another with astonishing velocity. The _Pteromys splendens_ belongs to Java and Borneo: his body is clothed in fur of a warm red hue. The _Sciuroptera Polatouche_, which inhabits the north of Europe and Asia, is of an ashen gray on the upper, and of a snowy white on the inferior parts. Some species of _Sciuridæ_ seldom ascend trees, but burrow on the ground, and are further distinguished by their possession of cheek-pouches. They form the genus _Tamias_. The best known is the Chipping Squirrel, Hacker, or Chipmuck (_Tamias Lysteri_), which abounds in the United States as far north as the fiftieth parallel, and derives his name from his peculiar _chipping_ or _cheeping_ cry, like that of a young chicken. He burrows near the roots of trees, and several squirrels frequently tenant one burrow, where they lay up stores of nuts and grain for winter supply. His length is fully ten inches; the general colour gray, longitudinally striped with yellowish-white and black. CHAPTER IX. MAN IN THE SAVANNAHS AND THE FORESTS.--ANTHROPOPHAGY.