HARPER: BOTANICAL CROSS-SECTION OF Misstssippr 391 
the flood-plains of smaller rivers, but they are here exhibited on a 
far larger scale than anywhere farther east. On the Mississippi side 
the ‘‘delta’”’ extends from a few miles north of the northern 
boundary of the state down to Vicksburg, nearly three degrees of 
latitude, or 200 miles in a straight line, and has its maximum 
width of 60 miles about midway, or just in the latitude where I 
crossed it. Generally speaking, it is a vast plain, sloping gently 
southward, at a rate of about a foot to the mile, traversed by 
numerous crooked, sluggish, muddy rivers and bayous, whose 
banks are usually a little higher than the interstream areas. The 
larger rivers of the delta, such as the Yazoo and Sunflower, are 
thirty or forty feet deeper at high water than at low water, have 
a perceptible current, and are navigable for steamboats most of 
the year, while the smaller bayous are stagnant much of the time, 
and fluctuate comparatively little. At least 90% of the area is or 
has been subject to occasional inundation from the spring floods 
of the Mississippi River (‘‘Father of Waters”), but the building 
of levees along the banks of the great river, in the last half century 
or so, has considerably restricted the overflows. 
The soil is mainly a fine gray silt, coarsest on the banks of the 
larger streams, where the current in times of flood is swiftest. 
Analyses published by E. A. Smith and E. W. Hilgard show that 
it contains 0.26-1.35% of lime, 0.30-1.10% of potash, and 0.11— 
0.30% of phosphoric acid. This is one of the most fertile soils 
known, according to Dr. Hilgard (Soils, 116, 345), and very little 
commercial fertilizer has been used on it as yet. Most of the area 
seems to be under cultivation now (cotton being the principal 
crop), but there is still considerable primeval forest with splendid. 
hardwood timber.* wer 
There is much valuable information about this region in 
Humphreys and Abbot’s voluminous government report on the- 
physics and hydraulics of the Mississippi River, 1861 (reprinted 
with additions in 1876). Other references are: E. A. Smith,. 
Proc. A. A. A. S. 20: 251-262. 1872; C. G. Forshey, Proc. A. A. 
A. S. 21: 78-111. 1873; Hilgard, Tenth Census §: 85-88, 241-247, 
319-321. 1884; Campbell & Ruffner, op. cit. 93-96, 105-107; 
© OY ae te the middle of the delta, but from all accounts the northern half 
Seems to be most extensively cultivated, and forests consequently more prevalent. 
in the southern half. 
