392 proceedings of the academy of [1887. 



December 6. 



Mr. Thomas Meehan, Vice-President, in the chair. 

 Twenty-six persons present. 

 The death of Evan Randolph, a member, was announced. 



The origin of the Grassy Prairies. Mr. Meehan said that in 1871 

 he had offered to the Academy some facts to show that the views of 

 the origin of the prairies, at that time generally accepted, could not 

 be sound, and he then suggested some points that must have had 

 considerable influence in bringing about this tree-less condition. 

 Among these points, he had named the annual prairie fires of the 

 Indians. Given a sheet of grass to be annually burned over, and 

 forests flanking it, trees, obviously, could not extend far. Young 

 sprouts from a tree stump would not flower. It took a seedling tree 

 or sprouts from a stump to persist in growth for a number of years 

 before its flowering stage is reached. Hence, though trees should 

 spring up on a gi-assy prairie, the annual burning to the ground pre- 

 venting the sprouts from reaching maturity, -would be an insujoer- 

 able bar to the surrounding forests encroaching far on the area of 

 the prairie. 



A further consideration, since that time, made it evident, that 

 tree seeds could scarcely get a chance to grow at all in these grassy 

 places. He had studied the so-called "balds" or open grassy places 

 on mountain tops and sides, surrounded on all sides by forests, where 

 there had been no annual fires, and yet no trees. He referred par- 

 ticularly to such spots on Roan Mountain, North Carolina. There 

 would be open spaces covered by a thick matted sod, the chief grass 

 composing it being Danthonia compressa. Sjsruce, Fir, Oak, and 

 representatives of other genera surrounded them on all sides. 

 Though the trees may have been fifty or even a hundred years old, the 

 grassy outline had evidently been definitely fixed years back, and 

 had not since been encroached upon until these later times. Since 

 cattle had been permitted to browse, young trees could be seen here 

 and there springing up. If the browsing continued, trees would 

 eventually cover the balds. In the past, seeds falling on the thick 

 matted grass, could not grow. There would be too much light and 

 too little moisture, so far from the ground. Should a seed sprout 

 under such circumstances, the radicle would dry up before it pushed 

 through the thick mass of grass to the necessary earth. Browsing 

 cattle kept down the grass, and gave the seeds a clmnce to reach 

 the ground, and their hoofs would often make the ground bare, and 

 even tread the seeds beneath the surface. Though eaten to the 

 ground, the trees would sprout again, some get stronger and larger, 

 and some eventually get to be trees, finally shading and killing out 

 the light-loving grass. While annual fires certainly prevented trees 

 spreading over grassy areas, we could now account for their non-ex- 

 istence, even as young seedling plants. 



