78 VEGETITION OF THE DRIFT. 



hope to do this — but, at present, would only call the atten- 

 tion of collectors to the interest which attaches itself to 

 these specimens, specimens which, if carefully preserved 

 and properly studied, will probably greatly aid us in giving 

 a satisfactory solution of the troublesome problem of the 

 deposition of the Drift ; for, although the mineral materials 

 of the Drift may, in many instances, indicate the character 

 of the rochy hasis of the country swept by the Drift cur- 

 rent, of its x)lants and animals, and hence of its topography 

 and climate, we have, uj) to the present time, but the most 

 limited knowledge. 



My observations have led me to regard the accumulations 

 of Drift materials, in circumstances similar to that described 

 by Mr. Miller, to a Neptunian rather than to a Plutonic 

 agency. 



I have regarded them as collections of transported mate- 

 rial — often transported from immense distances — which, 

 swept along the ocean bottom, found appropriate resting 

 places in the ravines and excavations made, either by the 

 Drift current itself, or by ancient water courses, as I have 

 failed to find satisfactory evidence of Plutonic disturbances 

 of the coal strata of Ohio, in any of the localities which I 

 have examined, except in a few rare instances, where the 

 disturbances are very slight. Our vallies are almost univer- 

 sally vallies of denudation, and our ravines and gorges, 

 perhaps without exception, due to the action of water. 

 These erosions of the rocky strata are not unfrequently met 

 with in the exi)loitation of coal mines, probably for the 

 double reason that the coal, at its outcrop, would, from its 

 softness, be so readily excavated by running water, and we 

 penetrate and explore the sub-stratum of this region almost 

 for nothing else than coal. 



EXTRACT FROM MR. MILLER'S LETTER. 



" A circumstance occurred in our neighborhood, about a 

 month since, that called my attention particularly, and I 

 have presumed to trouble thee with it. 



