CHAP. XXXIV.] DELTA OF MISSISSIPPI. 243 



habit this region, although the land quadrupeds were 

 almost entirely different. 



The delta of the Mississippi may be defined as that 

 part of the great alluvial slope, which lies below, or 

 to the south of the branching off of the highest arm, 

 or that called the Atchafalaya. Above this point, 

 which is the head of the delta, the Mississippi re 

 ceives water from its various tributaries ; below, it 

 gives out again, through numerous arms or chan 

 nels, the waters which it conveys to the sea. The 

 delta, so defined, is about 14,000 square miles in 

 area, and elevated from a few inches to ten feet 

 above the level of the sea. The greater part of it 

 protrudes into the Gulf of Mexico, beyond the 

 general coast line. The level plain to the north, 

 as far as Cape Girardeau, in Missouri, above the 

 junction of the Ohio, is of the same character, in 

 cluding, according to Mr. Forshey, an area of about 

 16,000 square miles, and is, therefore, larger than 

 the delta. It is very variable in width from east 

 to west, being near its northern extremity, or at the 

 mouth of the Ohio, 50 miles wide, at Memphis 30, 

 at the mouth of the White River 80, and contracting 

 again further south, as at Grand Gulf, to 33 miles. 

 The delta and alluvial plain rise by so gradual a 

 slope from the sea as to attain at the junction of the 

 Ohio (a distance of 800 miles by the river) an eleva 

 tion of only 200 feet above the Gulf of Mexico. 



First, in regard to the whole alluvial slope, whether 

 above or below the present head of the delta, it will 

 appear, from what has been already said, that sand 

 is thrown down near the borders of the main river 



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