266 SKETCHES OF CREATION. 



diminish materially the amount of soil upon an acre; and, 

 with the benefits which they confer, it is doubtful whether 

 they are not actually to be desired, especially in regions 

 subject to drought. A field will produce no more grain 

 with the stones picked out than with the stones left in. 



From our earliest knowledge of the prairies, speculation, 

 has been rife as to their origin. The old and popular be- 

 lief was that which attributed their treelessness to the an- 

 nual burning of the grass by the Indians. But the prairies 

 present other phenomena which the annual burning fails to 

 explain. Besides, the treelessness remains in regions where 

 the burnings have ceased. And, lastly, the treeless prairies 

 were not the only regions burned by the Indians. And if 

 they were, it seems more likely that the Indian burned the 

 rank grasses because the region was treeless, than that the 

 region became treeless from the burning of such vegetation 

 as flourishes in the shade of a forest. 



It has sometimes been suggested that the region was 

 originally forest-covered, and that the southern cane flour- 

 ished in such luxuriance amongst the trees as to rob them 

 of their moisture and nourishment, and thus cause their ex- 

 tinction. The cane, having deprived itself of the protecting 

 shade of the forest, was in turn scorched out by the rays 

 of the summer sun. This theory is every way unsatisfac- 

 tory. 



With others, the absence of trees is to be attributed to 

 the dryness of the atmosphere — and consequently of the 

 soil — at certain seasons of the year. It can not be doubted 

 that the treeless plains of the far West, and also other re- 

 gions, have failed to produce arboreal growths through an 

 insufficient supply of moisture. Still other treeless regions 

 are such from an excess of saline constituents in the soil. 

 But all such regions have nothing in common with the 

 prairies of Illinois except their treelessness. The topog- 



