AUSTRALIAN HALF-DESERTS 



a vigorous growth of plants will be better able to resist the 

 long eight or nine months'' drought, and so help the wood to 

 develop, until perhaps it is too thick, and the trees are too 

 high, for the antelopes to graze upon them. In this manner 

 the Acacia scrub is slowly and painfully colonizing the 

 desert. 



It is not only in Africa that one finds these half-deserts or 

 scrub. There is the Brigalow Scrub in Australia, which has 

 a curious silver-grey shimmering appearance on account of 

 the blue-grey sickle-like leaves of the Brigalow Acacia. 

 The foliage casts no shade, for the leaves are flat and thin, 

 and place themselves edgewise to the light, so that there is 

 no danger of the strong light injuring them. Also in 

 Australia is the Mallee Scrub, covering thousands of square 

 miles between the Murray River and the coast. It con- 

 sists of bushy Eucalyptus, six to twelve feet high. Its 

 monotonous appearance when seen from a small hill is very 

 striking.^ " Below lies an endless sea of yellow-brown bushes : 

 perhaps far away one may observe the blue outline of some 

 solitary hill or granite peak, but otherwise nothing breaks 

 the monotonous dark-brown horizon. Everything is silent 

 and motionless save perhaps where the scrub-hen utters its 

 complaining cry, or when the wind rustles the stiff eucalyp- 

 tus twigs."" 2 



There is a melancholy interest attaching to both the 

 Mallee and Brigalow, for in them lie the bones of many 

 gallant and persevering explorers. Nor is the East African 

 thorn-tree desert without its victims. The missionary. Dr. 

 Chalmers, was lost near Kibwezi in the Taru Desert. 



There are a certain number of valuable plants found in 

 these half-deserts or scrubs. Perhaps the earliest geo- 

 * Drude, Vegetation der Erde. ^ Drude, I. c. 



112 



