128 MOSTLY MAMMALS 



with which is the great desert tract extending through 

 Arabia, Syria, Mesopotamia, and Persia. By means of 

 the more or less desert tracts of Baluchistan, Sind, and 

 Kuch, this area leads on to the great Rajputana Desert 

 of India. More important is the vast Gobi Desert of 

 Mongolia, and other parts of Central Asia. In Southern 

 Africa there is the great Kalahari Desert, of which more 

 anon. In North America there is a large desert tract 

 lying east of the Rocky Mountains, and including a great 

 part of Sonora ; while in the southern half of the New 

 World there is the desert of Atacama, on the borders of 

 Peru and Chili. Lastly, the whole of the interior of 

 Australia is desert of the most arid and typical description. 

 But among these there are deserts and deserts. Tracts 

 of the typical barren, sandy type are, as already said, 

 extensively developed in the Sahara, as they are in the 

 Gobi and the Australian deserts. Between such and the 

 plains of the African veldt there is an almost complete 

 transition, so that it is sometimes hard to say whether 

 a given tract rightly comes under the designation of a 

 desert at all. A case in point is afforded by the South 

 African Kalahari. Although there are endless rolling dunes 

 of trackless sand, and rivers are unknown, yet in many 

 places there is extensive forest, and after a rain large 

 tracts could scarcely be called a desert at all. Mr. H. A. 

 Bryden, for instance, when describing the Kalahari, writes 

 as follows : " And yet, during the brief weeks of rainfall, 

 no land can assume a fairer or more tempting aspect. 

 The long grasses shoot up green, succulent, and elbow- 

 deep ; flowers spangle the veldt in every direction ; the 

 giraffe-acacia forests, robed in a fresh dark green, remind 

 one of nothing so much as an English deer-park ; the 

 bushes blossom and flourish ; the air is full of fragrance ; 



