THE GEOGRAPHY OF PLANTS. 7 



appearance of the vegetable world is the eame 

 as in winter with us. With us the cause is 

 want of heat in these regions the causa is 

 from want of moisture. Some of the American 

 plains, during the dry seasons, are as desert 

 as the Lybian wastes, but during the wet 

 season they are covered with luxuriant grasses 

 and the smaller acacias. 



