RECOGNITION OF THE CHARACTER OF SOILS. 513 



sion in the corresponding portion of Texas. On these prairies 

 we again find the calciphile vegetation, including the honey 

 locust, clumps of crab apple and red haw, etc., but not usually 

 any oak growth, except (near the seacoast) the live oak. In 

 the hilly country of northern Louisiana there is reproduced 

 substantially the vegetative character of the " short-leaf pine 

 and oak " uplands of Mississippi (see map on p. 490, chapter 

 24), save in that, owing to the occasional outcropping of the 

 calcareous materials of the Tertiary, small prairies with black 

 soil are spotted about here and there. Bordering the Missis- 

 sippi Bottom there are a series of oak-upland ridges with a 

 brown loam soil corresponding to the fertile area in north- 

 western Mississippi, with small patches of the " Cane hills " 

 loess soils, bearing a corresponding tree growth. 1 



In Western Tennessee the vegetative zones so distinctly 

 shown in the adjacent portion of Mississippi are not so strik- 

 ingly outlined, but so far as they do exist, the phenomena ob- 

 served accord exactly with those heretofore described. The 

 same holds true of Western Kentucky, as is well set forth and 

 graphically described in the reports of the geological surveys 

 of that state by Dr. David Dale Owen, and later by Dr. R. H. 

 Loughridge. 



North Central States. North of the Ohio River the mater- 

 ials of the geological formations are not nearly as much varied 

 as they are south of the same ; consequently the vegetative 

 features are also much more uniform. It must be remembered 

 that from the Alleghenies nearly to the Mississippi, the states 

 of Ohio, Southern Michigan, Indiana and Illinois are largely 

 covered by drift deposits overlying the older formations, except 

 that along the Ohio and Mississippi rivers lies the calcareous 

 loam of the Loess or Bluff formation. 



Within the states mentioned, however, not only are the older 

 underlying formations very generally calcareous, but calcar- 

 eous sand and gravel form a large proportion of the drift de- 

 posits, which in most cases overlie the rocks. Hence we find 

 from the Alleghenies to the Mississippi a predominance of the 

 oak forests which characterizes calcareous soils, as in the bet- 

 ter class of uplands in Mississippi and Tennessee; interrupted 



1 See " Final Report of a Geological Reconnoisssance of Louisiana," published 

 by the New Orleans Academy of Science in 1871. 



33 



