44 Rhodora [MARCH 
although the same perfectly elementary law of phytogeography could 
as well be brought out by contrasting the detailed ranges of many 
other species, such as Picea mariana and P. canadensis, Casianea den- 
tata and Juglans cinerea, Quercus Prinus and Q. Muhlenbergii, we may 
appropriately take for this examination the “ anomalous” and “irregu- 
lar” or “inconsistent” ranges emphasized by Hutchinson. 
Briefly, the “anomalies” or “irregularities” consist in the facts 
that, although the White Cedar, Thuja occidentalis, is “unusually 
large and fine in New Brunswick and the Gaspé peninsula,” it is 
unknown in Newfoundland, Cape Breton, and Nova Scotia where, 
we are told, “the climate, soil, etc., are the same”; and that, al- 
though Banksian Pine “extends northward to 56° N. lat. on the 
dry uplands east of Hudson Bay,” it is “practically eliminated from 
the low lying lands to the south and west of Hudson Bay and James 
Bay, water [so Hutchinson says] being the limiting factor." It is 
further stated that the “anomalous” distribution of Thuja occiden- 
talis “defies explanation by regarding temperature, water, or soil 
as the limiting factors” and, furthermore, that “CowLrs has shown 
that the composition of the rock from which any soil may be derived 
seldom acts in a limiting capacity with respect to the species which 
that soil may support. It is only in exceptional cases that a soil 
newly weathered, is deficient in the mineral constituents necessary 
for plant growth. This generalization is particularly applicable in 
Ontario, where the soil, whether it be glacial drift toward the south 
or the weathered deposits and exposed rocks farther north, is derived 
from the dominantly granitic rock of the Laurentian Plateau. The 
original composition of the soil is seldom a limiting factor, at least 
in so far as the forests of Ontario are concerned.” 
When we carefully study, however, the detailed ranges of these 
two species and take pains to discover the lithological character of 
each region where the species truly prospers and of all their outlying 
or extra-limital stations we shall find that, far from “defying explana- 
tion," the broad ranges and especially the outlying stations are 
readily explained by the chemical character of the soil, whether acid 
or basic. Pinus BanksIANa is confined to acid soils; 'THvJA occi- 
DENTALIS chiefly to basic soils and it reaches its maximum development 
and all its outlying stations only in positively calcareous areas. The 
evidence upon which these generalizations are made is stated below. 
