BANKS OF THE MISSISSIPPI. 361 



to return to the chanuel which they have abandoned. 

 They travel gradually towards tlie sea in innu- 

 merable tortuous canals, named hayous, which occa- 

 sionally swell out to form ponds or small lakes. 

 Like the principal stream, the bayous also undergo a 

 process of gradual elevation of their beds. A second 

 series of hayous branch out from the first, and a 

 third from these ; the elevation of these hayous 

 above the plain becomes less as the distance from 

 the main stream increases. The entire region pre- 

 sents an appearance opposite to that ordinarily met 

 with. The watercourses occupy the crests of low 

 hills, and their importance is the greater as the 

 height of these hills increases. Irrigation becomes 

 a very simple matter in such a country. 



The Mississippi extends very far into the sea. It 

 runs out between two banks of slight elevation, which 

 it continually lengthens. First, it converts he more 

 or less deep sea into shallows, which soon become 

 covered with a forest of aquatic plants and reeds. 

 A thick layer of mud is deposited at every flood, 

 whi(;h buries the stalks of the plants, and elevates 

 the bottom of the sea in such a manner as to form a 

 species of submarine delta. This deposit is increased 

 from year to year. 



Immense rafts of forest timber, carried to the sea 

 and again driven back by the waves, become covered 



