[Footnote 20: There are seven cities of the Beni M’Zab, of which five lie in the M’Zab Valley, close to one another. These are El Ateuf, Ben Noura, Melika, Beni Isguen, and Ghardaia. In the pre-French times these cities were bound together in a confederacy with Ghardaia as the capital. The M’Zabites are at present, and probably always have been, a peaceful trading folk. They are heterodox Moslems. In an early time they aroused the antagonism of their more warlike as well as more orthodox Arab neighbors of the Tell, who drove them away from the coast region, and again from Ouargla and other places settled by them, until safety was at last secured in the eleventh century in the “inhospitable Chebka.” Palm gardens were established which for centuries have been irrigated laboriously by very primitive methods, and the inhabitants have accumulated wealth in flocks and by barter. The relatively large population (there were 92,761 inhabitants in 1908), the really great number of domestic animals, and the great length of time which the region has been occupied, are all factors of importance in bringing about a modification in whatever way of the primitive flora.] [Footnote 21: In 1908, according to the Statistique générale de l’Algérie, there were cultivated in the territory of Ghardaia 572,114 fruit trees, among which were: almond, 5,850; fig, 101,722; date palm, 209,898; other sorts of fruits, 211,761. There were also 17,268 hectares of grain under cultivation.] [Footnote 22: We were informed by our Arab attendant that the kabar, particularly the fruit, made such animals as ate it insane. The spicy flavor of the plant might otherwise be distasteful to animals.] [Footnote 23: Fitting (Die Wasserversorgung und die osmotischen Druckverhältnisse der Wüstenpflanzen, Zeitschr. f. Bot., 4, 209-275, 1911) states that water-storage tissue is wanting, that in addition to being large, the leaves are much divided, without trichomes, and provided with thin cuticle. The stomata are fairly large, rather numerous, and not sunk. The leaves transpire rapidly and wilt soon after being removed from the stem. The osmotic pressure of the cell-sap of the leaves was found to equal 35.3 to 64 atmospheres, from which it is assumed that this plant, like others growing under desertic conditions, has a root cell-sap of great osmotic pressure, which permits it to extract water from a fairly dry soil or at a rather rapid rate. But neither at Biskra nor elsewhere, so far as I know, does _Peganum_ grow where the conditions are extreme, as might be concluded from the habit of the plant as given above.]