FLORAS OF EASTERN AND WESTERN NEWFOUNDLAND 247 
alpine flora in the acid, bleak, subalpine central and southern regions 
of Newfoundland, it is noteworthy that the North Pensinula, which 
separates the vast acid area of Newfoundland by scores of miles from 
eastern Labrador, is itself essentially a limestone region. It thus 
would seem that, although these oxylophytes abound on adjacent 
Labrador, their first landing, when they are blown as seeds or frag- 
ments across the Straits of Belle Isle to the Newfoundland coast, would 
be upon a forbidding limestone soil. Consequently the majority of 
these species have not yet achieved a successful start, although they 
are doubtless blown to the Newfoundland coast many times during 
every winter. In a few cases seeds have succeeded in passing the 
limestone barrier and colonies are now starting as new occupants of 
the acid region. 
From this brief analysis of the components of the Newfoundland 
flora it should be apparent, I think, that, if we are to get at the funda- 
mental ecological laws, we must take more thoroughly into account 
than is generally done the elementary principle that many, if not 
most, plants are highly selective in their soil requirements. Explain 
away this point as we may, it constantly obtrudes itself, and it is 
certainly the part of wisdom to recognize facts as they are and to take 
as a working principle the general formula, that the presence or absence 
of varying degrees of available lime or of other bases in the soil is more 
fundamental in determining plant distribution than are even considerable 
differences of temperature and humidity. 
Gray Herbarium, 
Harvard University 
EXPLANATION OF PLATES XV-XVII 
Plate XV 
1. American range of Saxifraga oppositifolia. 
2. Range of Salix vestita (including varieties). 
Plate XVI 
3. Range of Dry as integrifolia. 
4. Range of Lesguerella arctica (including var. Purshii). 
Plate XVII 
5. Range of Hudsonia ericoides. 
6. Range of Juncus militaris. 
7. Range of Arenaria groenlandica. 
8. American range of Salix herbacea. 
