1SG4.] DRUMMOND ON CANADIAN BOTANY. 417 



to localities previously far inland, and towards tlie lakes. The 

 lakes were then, doubtless, much larger than at present, and it 

 may be that at that time they were united into one vast inland 

 fresh-water sea, extending from near the then ocean-coast west- 

 ward. Means of diffusion was thus afforded, to these sea-shore 

 plants. The presence of extensive bodies of fresh-water would 

 have a moderating effect upon the atmosphere, which would, 

 with the exception of the absence of the saline element, be 

 much the same as that of the sea-coast. That the vicinity of 

 these lakes would form a not altogether unfavonible habitat 

 for a maritime vegetation is shown by the fact, that, as a general 

 rule, the maritime species scattered through Canada at the present 

 time, are only found in such localities. We may then readily 

 imagine that having become settled there, when, after the gradual 

 lapse ot" time, the waters of the lake retreated to their present 

 limits, these plants would follow, still continuing to retain their 

 positions near the shores, which would thus account for their wide 

 diffusion throughout the country at the present time. We may 

 then regard these peculiarly distributed plants as the relics of 

 a more extended maritime vegetation of the post-tertiary period. 



This theory of the causes of the distribution of sea-shore 

 plants over Canada, which I have briefly endeavored to explain, 

 resting as it does almost entirely upon a consideration of the past 

 geological conditions of the country, and upon some assumptions 

 not yet fully sustained by facts, may be open to objections. It 

 may be a question whether the facilities for migration to the ancient 

 lakes and for distribution along their shores, were, at that time, 

 so ample as I have supposed. Still it is conceived that the 

 peculiar diffusion of these species must have originated in some 

 such way as that conjectured. I cannot think that it is due to 

 mere accident. 



V. Alpine Type. 



The species enumerated in the list given below to illustrate our 

 alpine and sub-alpine floras have been chiefly obtained from the 

 Mingan Islands, Anticosti, and Gaspd. The Mingan Islands and 

 Auticosti have recently afforded to collectors many very interesting 

 alpine forms, — some hitherto unknown south of Labrador, unless 

 found upon the high alpine tops of the White Mountains. Draha 

 incaria,Cochlearia tridacti/Utes, Dry as integrifolia^RabusarcticuSy 

 and some other boreal forms detected there, form valuable additions 



