32 



So your zones of differing timber, as you ascend from 

 the alluvial swamps of the shores in your Southern states, 

 across the eocene and cretaceous beds to the mica slate, 

 gneiss and granite of the Appalachian chain, are the 

 consequences and indications of diversities in geological 

 structure. The swamp willow, the cypresses, {thyoides 

 and disticha) the swamp hickory, the green palmetto, the 

 tall magnolia, the red maple, and the cotton wood of the 

 lowest swampy spot — the hickory, oak, magnolia, beech, 

 walnut, tulip tiee, and holly, of the dry alluvial bluffs — 

 the perpetual pines of the tertiary (eocene) sands — the 

 naked prairie of the cretaceous marls — and the mixed 

 oaks, hickory and pines which appear on the pirmary 

 rocks — all these zones of different timber indicate the 

 natural connection of the vegetation of a district with the 

 nature of the rocks on which it rests. 



Nor are these geological relations of vegetable life with- 

 out their influence on the daily movements of your shifting 

 population. I have elsewhere shown how directly the 

 movements, the natural expansion I may call it, of our 

 first class farmers in Scotland, is not only influenced but 

 actually, as it were, prescribed, by the geological character 

 of the district in which they have been brought up and to 

 which they intend to move.* So it is among you. " Those 

 who go southwards from Virginia to North and South 

 Carolina, and thence to Georgia and Alabama, follow, as 

 by instinct, the corresponding zones of country. The in- 

 habitants of the red soil of the granitic region keep to their 

 oak and hickory; the 'crackers' of the tertiary pine barrens, 

 to their light wood ; and those who inhabit the newest 

 geological formations in the sea islands, to their fish and 

 oysters."t 



• See an article in the Edinburgh Review for March, 1849. 

 tLyell'a Second Visit to the United States, p. 110. 



