The French colony of Algeria is of large extent and possesses a highly varied topography and great range in climate. With an all-land connection with the continent of Europe in earlier geologic times, the flora and fauna of this portion of northern Africa are closely allied to the fauna and flora of southern Spain, France, and Italy. Algeria lies to the south of the Mediterranean Sea, between Tunis to the east and Morocco to the west. The northern portion extends somewhat beyond latitude 37°, or that of southern Spain, southern Greece, and the southern part of Asia Minor. The limit of the colony on the south is indefinite, reaching to about latitude 21°. Thus east and west the extent is about 650 miles, and north and south 1,200 miles. The most important topographical features of the northern part of Algeria are the several mountain masses which together constitute the Atlas range. Lowest in Tunis, where the Atlas Mountains do not exceed 5,000 feet altitude, they attain their greatest height in Morocco, over 13,000 feet. In Algeria an altitude of about 7,500 feet is reached in the Aurés, Dj. Chelia, and in the Great Kabylies. In the eastern portion of Algeria the mountains extend to the coast, but farther west a narrow strip of lowland separates them from the sea. In the east (in the department of Constantine) they constitute a single general uplift, although made up of several groups, but as one proceeds westward the mountains separate into two ranges, which at the Morocco border are about 125 miles apart. The two ranges have been called by various names, among which are the Great Atlas for the southern range and the Little or Maritime Atlas for the northern one. But it seems best to use the names Atlas of the Sahara or Saharan Atlas and Atlas of the Tell or the Tellian Atlas, names which are self-explanatory. The Tellian Atlas and all territory between this range and the Mediterranean Sea is known as the Tell, or the land of hills. This is the most important part of Algeria from an agricultural standpoint, and furnishes grain and other products. Here also are the most important forests, oak, pine, and cedar. Between the two ranges of the Atlas lies the region of the steppes or plateaus, in this study referred to as the High Plateau, inasmuch as the average altitude is over 3,000 feet. The steppe region is highest in the west and is wedge-shaped, in conformity to the bounding mountains. In the eastern portion it breaks up into mountain valleys. The topography of the High Plateau is monotonous. The surface is gently rolling, and here and there are undrained depressions, or _chotts_, where salts accumulate. In rainy seasons the chotts contain water, but in the arid summers they are dry. The region of the steppes is of no agricultural value, although, as will appear below, the harvesting of the alfa grass, which occupies vast areas, is of considerable importance.