I9I3-] STEVENSON— FORMATION OF COAL BEDS. 155 



rapid streams issuing from the Appalachians at the east and the 

 Canadian highlands at the north. The sluggish drainage was rend- 

 ered more uncertain by irregular subsidence, by formation of gentle 

 plications as well as by local elevation or subsidence in more or less 

 extensive areas. Almost the whole basin was land at the beginning 

 of the Pennsylvanian, as appears from the unconformity between 

 that and the underlying Mississippian, which is marked by an eroded 

 surface in all parts of the area, and by the absence of the Pocahontas 

 and New River beds from the northern portion, except in part of the 

 anthracite area. The gradual northward advance of the Beaver 

 deposits evidences the slow and frequently halted subsidence. The 

 conditions were wholly similar in Indiana and Illinois, west from 

 Cincinnatia, and they are equally distinct in Iowa and Missouri, west 

 from the JNIississippi river. In all this vast area of perhaps half a 

 million square miles, one finds the unconformity between Mississip- 

 pian and Pennsylvanian marked by extended erosion, and the first 

 beds of coal, in any district, are irregular, occupying more or less 

 isolated basins in the eroded surface. 



The relations of erect tree stems are important in this connection. 

 ]\Iuch energy has been expended in the effort to prove that trans- 

 ported trees can be deposited in vertical position ; but all that energy 

 has been wasted, for no one, familiar with the matter, ever had any 

 doubts respecting the matter. The possibility could not be dis- 

 puted; the doctrine of chances converted it into a probability and the 

 existence of snags in the Mississippi river made it a certainty. 



All such discussion is foreign to the subject and tends to divert 

 attention from the only point at issue, which is. Are these particular 

 stems in situ or not? Each occurrence stands alone and it must be 

 considered apart from all the rest. 



Erect stems have been observed in all coal fields and often in 

 such relations that not merely unscientific observers but also trained 

 geologists feel compelled to recognize that they are in loco nafali; 

 Jukes, when he saw the Parkfield stumps, admitted, though somewhat 

 grudgingly, that the trees certainly looked as though they had grown 

 there and that perhaps they had. The observations by Beckett, Ick, 

 Darwin, Goeppert, Sorby, Barrois and others, recorded in earher 



