154 THE OASES OF THE SAHARA. 



in the wilderness bewailed "the cucumbers and the- melons, the leeks, 

 the onions, and the garlics " of Egypt. 



M. Charles Martins classes the Oases of the Sahara under three 

 heads, corresponding to his three sub-regions.* 



The oasis of the Table Lands is watered by a stream or a copious 

 spring. That of the valleys of Erosion, by natural or artificial 

 Artesian wells. That of the Sandy Desert wants water. In the 

 latter the palm-trees are planted in conical cavities hollowed by the 

 hand of man, that their roots may strike down to the subterranean 

 reservoir which is to nourish them. 



Every oasis is composed, in the main, of date-palms, which seem 

 to form a continuous forest ; but in reality they are planted in rows, 

 and in gardens separated from one another by walls of earth, which 

 are pierced with an aperture to admit of the entrance of the irrigating 

 rill into the enclosed square. The soil employed in the construction 

 of the walls is removed from the paths, which are consequently below 

 the surface, and can be employed for a double purpose ; they facili- 

 tate circulation in the oases, and the waters, after having refreshed 

 the gardens and revived the soil, discharge themselves into these 

 hollow ways, whence they flow towards the chotts, or stagnate in 

 swamps, which the lethargic Moslem never thinks of draining. From 

 such hotbeds of infection issues the monster Fever every year, and 

 slays its hundreds. 



In case of need, every oasis becomes a fortress. Each " square of 

 flowery ground " is a redoubt ; the assailant's bullet lodges in the earth 

 wall, or if it pierces through, forms a new loophole in which the 

 Arab plants his gun to aim at his enemy. The villages themselves 

 are encircled with walls, flanked by towers, which remind the spec- 

 tator of the picturesque fortifications of mediaeval times. 



The Date-Palm (Phoenix dactyUfera) is the tree of the Desert ; 

 there only will its fruits ripen ; without it, the Desert would be 



* Martins, " Du Spitzberg au Sahara," pp. 565, et seq. 



