ACACIA V. CAMEL 



These acacias are quite well fitted to live in this dry and 

 arid region. Their roots go down to twenty feet or more, 

 so as to reach the deep-seated water supplies. 



Their leaves are generally adapted to resist any injury 

 from the strong glare of the sunshine. The gums, already 

 alluded to, are also very important, for any crack or break 

 in the tree is promptly gummed up, and there is no loss of 

 precious water thereby. This gum will also prevent or dis- 

 courage burrowing and boring insects from getting in ; they 

 would, if they tried to do so, become " flies in amber,"" like 

 those found in fossil resin. The trees are generally pro- 

 vided with strong spines, which guard them from the many 

 grazing animals which try to devour the succulent leaflets. 



The fight between the grazing animal and the plant is, in 

 these scrubs and half-deserts, very severe. In Egypt it is 

 said that the whole flora has been entirely altered by the 

 camel and the donkey.^ 



But in this case the battle is unfair. Man keeps those 

 camels, donkeys, and goats. He provides them with water 

 and protects them from lions, leopards, and snakes. In East 

 Africa man has not yet interfered, and the plants probably 

 get the better of the animals. In such places lions, leopards, 

 and hyenas are common. It will be remembered that a lion 

 not very long ago stormed and took charge of a railway 

 station on the line to Uganda, and was only routed with 

 very heavy loss. 



There is also some reason to suppose that the antelopes 

 and other creatures do help the plants in their efforts to 

 colonize the Sahara. Their droppings will very greatly im- 

 prove the soil, and more vigorous thickets and undergrowth 

 will spring up when the soil is improved in this way. Such 



> Floyer. 

 Ill 



