148 POPULAR GEOGRAPHY OF PLANTS. 



whose measurement is given above, is probably three hun- 

 dred. They are usually seen on the hills, in a light, dry, 

 sandy soil, where nothing else will grow. The Argan 

 (which is said to be a low-spreading tree or shrub, varying 

 in size according to locality) belongs to the Natural Order 

 Sapotacea : its chief value arises from the oil which is ex- 

 pressed from its kernels. 



But the most important feature of vegetation in North 

 Sub-tropical Africa is doubtless the Date Palm (Phoenix 

 dactytifera) (Plate XX.), constituting, as it does, the sole 

 means of support to nineteen-twentieths of the population 

 of Fezzan during nine months of the year; forming the 

 food of beasts as well as of human beings, "the oases 

 being bare of herbage." Though it is cultivated as far to 

 the north as 41 in Spain, as well as in the south of Prance 

 and in Italy, at Athens and at Smyrna, the fruit does not 

 ripen there. Its true native home is the North of Africa, 

 Egypt, Nubia, Syria, Arabia Pelix, and Persia. The range 

 of the Date Palm is limited towards the south by the re- 

 gion of equinoctial rains. A sandy and well-watered soil 

 is that which best suits this tree, for which reason it is 

 always found in the great African deserts in the neighbour- 

 hood of springs. 



