12 PROCEEDINGS OF THE ACADEMY OP [1881. 



from the foct that it required but the same conditions for the 

 seeds of trees as for those of lierbaceous plants, the number of 

 species of which on the prairies was well known to be very large. 

 Another great gain to our present knowledge, was that since the 

 annual firing of the grass}^ prairies had been discontinued by the 

 advance of civilization, the timber was everywhere encroaching 

 on them. Among the facts which he otfered in proof of this, was 

 a reference to p. 505 of the Yth Report of the Geological Survey of 

 Indiana, where Dr. Schneck shows how land which was once grassy 

 prairie, is now covered with a luxuriant growth of forest trees ; to 

 the evidence of Major Hotchkiss, Geologist of Staunton, Vir- 

 ginia, that the Shenandoah Vallej', now heavily timbered, was 

 clear of trees in the early history of Virginia ; to the discovery 

 of buffalo bones, in caves near Stroudsburg, Pa., by Dr. Joseph 

 Leidy, — now a timbered region, the buffalo only existing in open, 

 grassy countries ; ^ and to various traditions of settlers in some 

 valleys now timbered, that the land was originally clear of trees. 

 He pointed out that in all known parts of the United States at 

 the present time, except the arid regions, where only drought- 

 loving plants could exist, the natural result of freedom was the 

 succession of forest growth. Seeds were scattered by winds or 

 animals over acres of cleared land ; if such land became neglected, 

 these, again seeding in time, extended the forest area continu- 

 ally'. The tallest growing vegetation, lilic trees, crowded out the 

 weaker, and the forest naturally crowded out the lower growing 

 and weaker herbaceous plants. He illustrated this by reference 

 to the neglected cotton-fields of the Southern States. 



From all this, the speaker said that it was evident that there 

 was nothing in Nature either now or in the past, to prevent the 

 gradual encroachment of the forest over the grassy plains, till long 

 before the white man came here, the whole would have been com- 

 pletely covered by arborescent growth. Were there any artificial 

 causes equal to the exclusion of trees, and j^et permitting an her- 

 baceous growth ? If we were to sow a piece of land in the 

 autumn with some tree seed and some seeds of annuals, the latter 

 would be up, flower, mature and scatter their seed to the ground 

 before the next autumn, and many of these seeds would be washed 

 into the earth, or drawn into the eai'th by insects or small animals. 

 But tree seed would make young trees, which would not again 

 produce seed for ten or more years. If now, at the end of this 

 first season, a fire swept over the tract, the seeds of the annuals 

 which had found a slight earthy protection, would come up 

 again the next summer, again seeding and extending the area. 

 The trees would be burned down, and though perhaps many would 

 sprout, successive bui-nings would keep them confined to one 

 place. In short, under annual burnings, herbaceous plants could 



> Since the reading of the paper, it has been brought to the attention of 

 the author, that the bones may have belonged to the Wood Buffalo. 



