1900] Fernald, — Some Jesuit influences upon our flora 139 
formerly adapted themselves to live near it found the proper con- 
ditions for their growth moving northward. Accordingly, as the ice 
receded further and further, these plants reproduced themselves and 
attained their greatest development more to the north than before. 
They were closely followed in their migration by others which required 
somewhat less arctic conditions, until a very general northward move- 
ment was made by all the plants crowded during the glacial period 
into the southern half of our hemisphere. The time has long since 
passed when the arctic species in their poleward march covered New 
England, the region of the Great Lakes and of the Rocky Mountains. 
But on the higher mountain-summits, on sheltered rocky shores, and 
on fog-enshrouded coasts these plants seem to have found congenial 
conditions; at least, on the upper Rockies and the White Mountains, 
on the northern shore of Lake Superior, on the eastern coast of New 
England, and in cool, sheltered spots in the interior, they have per- 
sisted as isolated remnants of a flora which once covered all the country 
about us, but which is now of general occurrence only in the far north. 
Through continental Europe and parts of Asia, the campion, mug- 
wort, field sow-thistle, and hawkweed are very common, and they even 
extend north to the Arctic Ocean. It would seem natural, then, that, 
if they were to be grouped with the other European plants, the yellow- 
rattle, etc., which have a similar range south of the St. Lawrence, we 
should find them throughout Arctic America, on the Great Lakes and 
in the Rocky Mountains. But this is not the case: the most northern 
recorded station seems to be that of the mugwort on Hudson Bay ; 
and there are no records, as far as we know, for any of the four plants 
on our Arctic coast or in the Rocky Mountains. Considering, then, 
their very restricted range in America, it is probable that these plants 
were at some time introduced ; but there are no available historic 
records by which this can be proved. There are surely no large towns 
in the forests of Maine, New Brunswick and Quebec, and it does not 
really seem probable that plants have been brought to the shores of 
our northern rivers through the means by which they ordinarily reach 
our city streets and waste places —the importation of foreign goods 
and the constant shipping from one place to another of packing in 
which the seed may have lodged. 
The early history of the country through which these plants are 
found suggests, however, a possible explanation. In 1:534, Jacques 
Cartier entered the Strait of Belle Isle and found French fishermen 
