OF NATURAL HISTORY. 63 



they can perform a journey of fifty leagues into the defert, which 

 cuts off every approach from their enemies. All the armies in the 

 world would perifli in purfuit of a troop of Arabs. An Arab, by the 

 alliftance of his camel, furmounts all the difficulties of a country 

 which is neither covered with verdure, nor fupplied with water. 

 Notwithftanding the vigilance of his neighbours, and the fuperiori- 

 ty of their ftrength, he eludes their purfuit, and carries off, with 

 impunity, all that he ravages from them. When about to undertake 

 a depredatory expedition, an Arab makes his camels carry both his 

 and their own provifions. When he reaches the confines of the 

 defert, he robs the firft paffengers who come in his way, pillages the 

 folitary houfes, loads his camels with the booty, and, if purfued, he 

 accelerates his retreat. On thefe occafions he difplays his own talents 

 as well as thofe of the camels. He mounts one of the fleeteft, con- 

 ducts the troop, and obliges them to travel day and night, without 

 almoft either flopping, eating, or drinking; and, in this manner, he 

 often performs a journey of 300 leagues in eight days. 



Another order of quadrupeds deferves our notice. Thofe which 

 ha\e been diftinguifhed by the appellation of amphibious, are ca- 

 pable of remaining a long time under water. They live chiefly up- 

 on fillies, and, without this faculty of continuing a confiderable time 

 under water, they would be unable to procure their food. To this 

 tribe belong the feal, the walrus, the manati, the fea-lion, &c. The 

 fcal and walrus are more nearly allied to land-quadrupeds than to 

 the cetaceous animals ; becaufe they have four diltindl legs, though 

 nothing but the feet project beyond the Ikin. The toes of the feet 

 are all conneded by membranes, which enable thefe animals to fwim 

 in queft of their prey. They differ from terreftrial quadrupeds by 

 the fingular faculty of living with equal eafe either in air or in wa- 

 ter. This peculiarity of oeconomy and manners prefuppofes the 

 necefiity of feme deviation from the general ftrufture of quadru- 

 t I peds J 



