173 
This flora was modified by the effect of the last great glacia- 
tion which drove many northern species southward into this 
Beacon Hill or pine-barren area, in which some still persist, no- 
tably the Bearberry and Broom Crowberry. 
Another interesting explanation of the character of the pine- 
barren flora is suggested by Professor M. L. Fernald of Harvard, 
in an article in Rhodora, the journal of the New England Botan- 
ical Club, for February, 1931, entitled “Specific Segregations 
and Identities in Some Floras of Eastern North America and 
the Old World.” By means of paleogeographic maps, after 
Schuchert, Professor Fernald shows land connections between 
North America and northern Europe and Asia, which may ac- 
count for the likenesses in many plants common to these con- 
tinents. He points out the occurrence in the high mountains of 
eastern Tennessee of a number of species also found in the New 
Jersey pine-barrens. He supposes that these species were once 
numerous in east Tennessee when the region was a low, nearly 
base-levelled peneplane, in the Cretaceous Period. When it was 
later uplifted, species from the north, deriving from northern 
Europe and northern Asia, moved south, into the new high- 
lands and the members of the groups of tropical and sub-tropi- 
cal forms, once contented in the peneplaned lowland, were 
forced out into conditions more to their liking in the emerging 
coastal plain where acid savannahs, bogs, shallow pools and dry 
sands supplied the conditions which permitted them to survive. 
The occurrences of what we regard as typically pine-barren spe- 
cies in the Great Smokies are therefore probably dying remnants 
of a much larger distribution, migrants from which spread east- 
ward and downward to conditions like those which existed in 
East Tennessee before the post-Cretaceous uplift. 
These interesting attempts to interpret our pine-barren 
flora probably all have some measure of truth, but their authors 
would doubtless admit that they may have to be changed by 
later discoveries. That botanists of note may differ is indicated 
in Dr. Stone’s footnote on Corema, Professor Fernald regarding 
it as a Coastal Plain plant pushing north to Newfoundland, 
while Dr. Stone had always looked upon itasa northern species 
ranging south to New Jersey. 
Hollis, N. Y. 
