32 TRANSACTIONS ‘OF THE CANADIAN INSTITUTE. [ VoL. VIII. 
and smaller sheets of water to the east and south of it—all of which were 
close to or formed part of the Pleistocene seas—is confirmatory than 
otherwise of the origin of the remarkable range of these plants. If this 
hypothesis be correct, these inland sea shore plants can be regarded as 
one of our older floras, dating back to the times of the Leda clays. 
The most remarkable feature in the eastern coast distribution is 
the absence of such a large number of the familiar trees, shrubs and 
herbaceous plants of the Upper St. Lawrence valley. The Appalachian 
chain of mountains has no doubt acted as a barrier to the western pro- 
gress of many plants, as it has to the eastern extension of many others. 
The lower temperature, the moister atmosphere-and the prevailing fogs, 
so pronounced on the immediate coast, especially of Nova Scotia, New 
Brunswick, Newfoundland and the St. Lawrence estuary, must exercise 
considerable influence inland as well, though this influence necessarily 
diminishes as the distance from the coast increases. Again, the cold 
Labrador current, by a branch through the Straits of Belle Isle, extends 
its influence up the St. Lawrence on both sides towards Quebec, whilst 
its main stream, after washing the eastern coasts of Newfoundland, 
spreads along the Nova Scotia and New Brunswick coasts in its course 
south-westward. Of the effect of this broad cold current on plant life 
on the immediate coast, there is no question. The insular character of 
Nova Scotia and its elongated shape would rather intensify than other- 
wise these effects on plant life within it. We miss in this province the 
basswood, the ironwood and all of the hickories and have only one species 
of elm, one of ash and one of oak, whilst the white cedar is unknown 
through most of the province. 
We can readily account for the large and important representation 
of plants found immediately north of Lake Erie. This section of On- 
tario is not only farther south than any other part of Canada, but practi- 
cally forms a peninsula with all the advantages of a peninsular climate. 
It is in the latitude of Western New York, and, in part, of Northern 
Pennsylvania and Northern Indiana and has within it most of the plants 
of these states. Lake Erie would form in one respect a natural barrier 
to continuous northward range of southern plants but on the other hand 
the.currents and the winds of Lake Erie facilitate this range to a con- 
siderable extent. On the Pelee Islands, and on Point Pelee and other 
jutting headlands on the north shore, there are met representatives of 
the more southern flora of Ohio and Indiana. Another interesting fea- 
ture is that in the counties bordering Lake Erie the trees are very well 
distributed. It is possible to find on a single farm of 200 acres, more 
than half of the species of trees which occur in Ontario. 
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