732 



THE WONDERS OF GEOLOGY. Lect. VII. 



in the Bay of Fundy, where the roots of the erect trees 

 are in contact with a thin bed of pure coal. It seems pro- 

 bable that in these, and many other instances of a like 

 nature, the verticality of the trunks may have originated 

 simply from the trees having floated with their stems upper- 

 most, in consequence of their roots being loaded with soil. 

 This is a constant occurrence in the great floods of the 

 American rivers; the snags, as they are termed, which 

 often render the navigation difficult and perilous, being 

 formed by drifted trees forced into an oblique direction by 

 the current. Trees in an upright position are often carried 

 out to sea, and have been seen far from land, floating with 

 their topmost branches above the water. 



But if more extended observations should establish the 

 fact, which the late discoveries have rendered highly pro- 

 bable, namely, that the roots {Stigmarice) of the forest- 

 trees {Sigillarice) of the carboniferous system, are inva- 

 riably present, and for the most part in their natural 

 position, in the under-clay, and beneath each bed of pure 

 coal {ante, p. 667), we then cannot refuse our assent to the 

 conclusion that those trees grew on the areas now occupied 

 by their carbonized remains. Yet may we not inquire, 

 whether these facts will not admit of some other interpre- 

 tation than that which attributes the phenomena to the 

 effect of alternate subsidence and elevation of the land? 

 May there not have been extensive inland areas, de- 

 pressed, like the basin of the Caspian, many hundred feet 

 below the level of the sea, and affording the shelter, warmth, 

 and moisture, required by an intertropical flora ; and sub- 

 jected to periodical inundations from mountain torrents, 

 poured down from alpine regions on which the pines and 

 other coniferae associated with the arborescent ferns of the 

 coal, may have flourished ? Would not such physical con- 

 ditions, modified by occasional changes in the relative level 

 of the land and water by subterranean movements, meet the 



