The region of the table-lands, or Saharan Steppes, the valleys of Erosion, and certain parts of the Gobi--Persia, Syria, and Arabia--which are not absolutely deprived of rain, or which are refreshed by mountain-streams, nourish several species of mammifers: gazelles, hedgehogs, porcupines, hares, offering both to man and the carnivora an abundant variety of game. Of all these animals, the most interesting are the gazelles, several species of which inhabit the desert region. I shall refer in the first place to the gazelle properly so called, or _Antilope dorcas_, so remarkable for the grace of his movements, his slender limbs, and the expressive gentleness of his eyes. This beautiful species is common in Central Sahara, Nubia, and Asia. He lives in numerous troops, is of small stature, with a yellowish or yellow-brown skin on the back, and a white belly, a brown or blackish belt marking the sides. The horns, larger and stronger in the male than in the female, have a double curve, are lyrated, and without projections. The Ariel Gazelle is about twenty inches high at the shoulder. The _Gazella Soemmeringii_ belongs to Abyssinia and Sennaar. The gazelle _nanguer_ is found as far as Morocco, Nubia, and in the Cordofou; some varieties occur at the Senegal. Finally, the oryx-leucoryx inhabits Tropical Africa, and rarely makes his appearance in the Deserts; he differs from the gazelle in his arched horns, but his skin is nearly the same. Although the gazelles are generally considered extremely timid animals, which, moreover, their weakness would fully justify, they display on emergency a surprising courage. When they cannot escape from danger through agility, they bravely confront the enemy which attacks them. Menaced by a panther or a leopard, they form themselves into a circle, which, bristling everywhere with keen-pointed horns, compels the antagonist to retreat. [Illustration: 1. Gazelle. 2. Antelope (_Oryx-leucoryx_). 3. Gazelle (_of Soemmering_). 4. Nanguer.] In the deserts of Africa and Arabia the traveller frequently meets with small rodents, which excavate their burrows in the sandy soil, and only issue from them at night in quest of food. These are the jerboas and jerbilles. The jerboas are easily recognized by the length of their hind-legs and the disposition of their toes--three to each hind-foot, the middle larger than the rest; five to each fore-foot; and all furnished with sharp, strong, crooked claws; their structure resembling that of the _raptores_ among birds. These animals leap with great celerity, and to an extraordinary distance. The tail, which is a fifth longer than the body, and terminated by a tuft of black hair, forms at one and the same time a sort of balance, a rudder, and a lever. It enables the jerboa to preserve his equilibrium, and to direct himself when he has taken his spring; or, in a state of repose, furnishes him with a substantial support. [Illustration: GAZELLES OF ARABIA OPPOSING A PANTHER.]