The Advance of the Desert 



of Afforestation. For by trees we shall be able 

 to fling back the desert zone till the gushing 

 waters of the Eye of Kuruman will once more 

 seek the dark canons of the " Great River " * 

 and sweep outwards to the delta at the sea. 



The Kalahari offers an admirable field for 

 agricultural exploration. Take for example 

 the vegetation of the desert. Here you find 

 plants which have been growing for ages upon 

 a limited rainfall. Think of the excellent 

 drought-resistant qualities which they must 

 have developed. Such plants are of special 

 value to the dry farmer. In this connection 

 we may single out the bushman grass. During 

 some years this hardy plant does not receive 

 four inches of rain. Yet it grows and seeds, 

 and cattle get fat upon it. Then take the 

 wonderful tsamma melon, well called the life- 

 blood of the desert, which thrives merrily on 

 a scorching sand-dune. Can any dry land be 

 too dry for it ? And then the dainty desert 

 flowers : crimson and purple, and purest snow, 

 fit to adorn an English queen. Pass from the 

 subject of economic plants to the question of 

 pure science. What a rich field of discovery 

 awaits the patient investigator ! We crossed 



1 See Chapters XII. and XIII. 



7 



