BIRD-LIFE IN NORTHERN AFRICA. 101 



indiscriminately with African resident species. In the 

 Great Desert, which stretches far away to the southern 

 horizon, we may be sure of meeting with various forms 

 of bird-life. What erroneous ideas prevail respecting 

 the physical aspect of the Desert ! Imagination pictures 

 a vast level tract of sand, stretching away to the distant 

 horizon in an unrelieved expanse, glowing in blazing 

 sunlight, the air stifling and hot. Reality shows a vast 

 area of uneven country, like many a rocky district in the 

 North of England, full of hills and dales, and dried up 

 water-courses, the only difference being the presence of 

 sand, and the entire absence, or nearly so, of vegetable 

 life. Low ridges, high plateaux, desolate valleys, big 

 boulders of rock, and stretches of shifting sand, in which 

 the traveller sinks up to his knees, are characteristics of 

 the awful scene of waste. Dark specks on the horizon 

 denote the oases and wells, the footsteps of camels and 

 horses here and there mark the tracks which are 

 followed by the fierce and warlike people of the wilder- 

 ness, and the bones of sheep tell the camping places of 

 travellers. The rarefied air seems to dance and sparkle 

 above the rocks and sand dunes ; the sky for months 

 never shows a cloud, and the fierce rays of the sun beat 

 down with overpowering force. Every description of 

 physical scene prevails in the Desert, which even the 

 absence of vegetation cannot make monotonous. Near 

 the oases the pretty little Desert Lark lives among the 



