CHAPTEE VII 



THE CONTINENTAL BASIN 



Bounded in the east by what might collectively be termed 

 the Atlantic Mountains and in the west by the Pacific Moun- 

 tain system lies the immense continental basin. It is open 

 to the sea both in the north and south, extending in one 

 continuous series of plains and plateaux from the Gulf of 

 Mexico to the Arctic Ocean. The northern portion of this 

 great interior basin has already been briefly described in the 

 second and third chapters. The rivers of this part of the 

 continent drain eastward to the Atlantic Ocean and northward 

 to Hudson Bay and the Arctic Ocean. The drainage of the 

 southern portion is supplied almost entirely by the Missis- 

 sippi, and is thus discharged into the Gulf of Mexico. It is 

 this southern section of North America and its fauna with 

 which I propose to deal very briefly in this chapter. 



The low-lying and gently seaward -sloping belt of land 

 bordering the Gulf of Mexico is known as the " gulf plains." 

 It is here in this rich soil that sugar-cane, cotton and rice are 

 cultivated. The west- central part of the continental basin 

 is occupied by the " prairie plains." By the term " prairie " 

 we recognise a level region, either a plain or a plateau, with- 

 out forests, but clothed in a carpet of luxuriant grasses and 

 flowering annuals. On their eastern and northern border 

 these prairie plains merge into the adjacent forested plains, 

 while in the west they gradually pass into the more elevated 

 and drier high plains, where bunch grass, with bare intervals 

 between the scattered tufts, takes the place of the continuous 

 sod of the true prairies. 



There is a widespread popular belief in Europe that the 

 whole of the vast American continental basin is one extensive 

 prairie or pasture land. This is quite a mistake. As we 

 approach the Mississippi River from the west we gradually 



