THE TRIBES OF THE SAHARA 71 



prudent economy the villages are built on the borders of the 

 oases on the unfruitful soil, so that not a foot of ground sus- 

 ceptible of culture may be lost. 



Sedentary Berber tribes inhabit the oases, and chiefly live 

 upon the fruits of their date-trees ; while the nomadic Tuaryks 

 and Tibbos wander, with thei^ camels and sheep, over the desert 

 in quest of scanty forage and thorny shrubbery. In spite of 

 their mutual hatred, the bonds of a common interest connect 

 the vagrant and the agricultural tribes. Condemned to per- 

 petual migrations, the nomade is forced to confide all the 

 property which he is unable to carry about with him to the 

 inhabitant of the oasis ; he may even possess a small piece of 

 land, the cultivation or care of which he intrusts to the latter, 

 who, on his part, as soon as he has saved something, buys a 

 sheep or a goat, which he gives in charge to the nomade. 



An unmitigated hatred, on the contrary, exists between the 

 various erratic tribes, as here no mediating self-interest softens 

 the antipathies which are almost universally found to exist 

 between neighbouring barbarians ; and their robber-expeditions 

 not merely attack the richly laden caravan, but also the oasis 

 which may be connected by the bonds of intercourse with their 

 hereditary enemies. 



The vast tracts of sterile sand, where not even the smallest 

 plant takes root, and which might be called the " desert of the 

 desert," present the greatest conceivable contrast to its green 

 oases. With the vegetable world the animal kingdom likewise 

 disappears, and for days the traveller pursues his journey with- 

 out meeting with a single quadruped, bird, or insect. Nowhere 

 are the transitions of light and shade more abrupt than in the 

 desert, for nowhere is the atmosphere more thoroughly free of 

 all vapours. The sun pours a dazzling light on the ground, so 

 that every object stands forth with wonderful clearness, while 

 all that remains in the shade is sharply defined, and appears 

 like a dark spot in the surrounding glare. 



These harsh contrasts between light and shade deprive the 

 landscape of all grace and harmony ; but this want is amply 

 compensated by its singular grandeur. The boundless horizon 

 and the silence which reigns over the whole scene, have a 

 powerful effect upon every one who for the first time enters 



F 4 



