252 SKETCHES OF CUE AT ION, 



cases it would seem highly improbable that the seeds of 

 such plants had recently been transported to such situa 

 tions at the moment when the disappearing forest admits 

 the introduction of the conditions essential to their growth. 

 It can hardly be doubted that the seeds existed in the soil, 

 ready to germinate whenever free sunlight, warmth, and 

 atmospheric air should be permitted to rouse their latent 

 vital energy. Of the same nature is the recurrence of par 

 ticular forest growths upon the same soil. Not unfre- 

 quently the second growth is of a very different nature 

 from the first. In the &quot; old fields&quot; of Virginia and other 

 Southern States, the soil, cleared originally of the decidu 

 ous forest, and then abandoned after years of continuous 

 cropping, sends up a growth of pines instead of deciduous 

 trees. In some parts of Southern Ohio, as I have been in 

 formed, a forest of unmixed locust-trees follows the destruc 

 tion of the ordinary mixed forest. 



Mr. Marsh, in his learned work entitled &quot;Man and Na 

 ture,&quot; has quoted from Dwight s &quot; Travels&quot; his account of 

 the appearance of a fine growth of hickory on lands in 

 Vermont which had been permitted to lie waste, when no 

 such trees were known in the primitive forest within a dis 

 tance of fifty miles. He quotes also Dr. Dwight s account 

 of the appearance of a field of white pines, on suspension 

 of cultivation, in the midst of a region where the native 

 growth was exclusively of angiospermous trees. &quot;The fact 

 *that these white pines covered the field exactly, so as to 

 preserve both its extent and figure,&quot; says Dr. Dwight, 

 &quot; and that there were none in the neighborhood, are de 

 cisive proofs that cultivation brought up the seeds of a 

 former forest within the limits of vegetation, and gave 

 them an opportunity to germinate.&quot; 



In this connection may be quoted a statement of Darwin, 

 in &quot;The Origin of Species,&quot; to the effect that in the midst 



