Origin, Extension and Continuance of Prairies. 41 



out almost any family of trees. When the cane has driven out every 

 tree and has acquired exclusive possession, it then begins to experi- 

 ence the consequences of exposure, without the shelter from the 

 sun's rays which is afforded by the trees. The influence of the sun 

 upon a cane-brake, unprotected by the trees, will in time produce 

 the destruction of both stalk and root, by which means the land will 

 fail to be occupied again by cane, until it has been covered anew 

 with trees. Under favorable circumstances, the seeds of grass are 

 always at hand, as well as those of trees ; but the grass is quickest 

 to shoot and grow, and will soon afford a dry carpet, which, if set on 

 fire at the proper time, will readily burn and destroy any young trees 

 that had sprung up; the grass will now continue to increase in quan- 

 tity and to improve in quality as the cane-roots are decomposed and 

 the annual fire is continued. But, on the other hand, if the firing is 

 not carried on, the. trees will, in a very few years, by their shade, 

 exclude the grass ; and should the land be adapted to the kind of 

 trees that spontaneously appear, they may become so thickly set, as 

 to form such a complete barrier to the sun and light, that even the 

 cane will be kept from returning, and can regain its former residence 

 only by taking hold at the time the trees are exchanging places ; as, 

 for instance, when one family, composed of such trees as usually 

 accompany each other, are becoming thinned by death, and thereby 

 making room for another to occupy the land. 



There is no fact that can be better established than that prairies 

 are formed, and are' now forming, by the operation of wind and fire. 

 Very abundant proof was exhibited to the writer, more than twenty 

 eight years ago, when making a pedestrian journey through the dis- 

 tant and extensive regions of the west. He has seen the prairie in 

 all its stages ; he has seen the hurricane at work upon the forest. 

 He has seen places where the inroad had been made only the' year 

 before ; where the grass stood but thinly on the ground, and where 

 it had become sufficiently luxuriant to burn. When the first burn- 

 ing took place, the timber was, in some places, partly consumed, and 

 in other places altogether burnt off, leaving holes in the ground, made 

 by the action of the fire upon the trees, which were burnt when stand- 

 ing, and thus the stump part was consumed beneath the surface of the 

 earth. 



When a hvirricane makes an inroad upon a forest, the rays of the 

 sun are then admitted to the earth, and this at once affords an oppor- 

 tunity for the grass to spring up ; and if the land is rich and the sun 



Vol. XXIII.— No. 1. 6 



