
66 Rhodora [Mane 
plains south of them, under any imaginable conditions of climate, is 
quite as far beyond the range of possibility as to extend across the 
wide ocean.” a, 
The fact that many plants are calcicolous, many calcifuge, is clearly = 
recognized by the European ecologists, Tansley in his won lly 9 
lucid little book, Types of British Vegetation, saying with perfect posi- — 
tiveness: “Soils containing a comparatively large proportion of lime — : 
are always marked by the presence and usually by the abundance of — . 
certain species of plants — the so-called ‘calcicole’ species....Con- 
trasting with the ‘calcicole’ species there are others, called ‘calcifuge” . 
which appear to be really intolerant of much lime in the soil.”? — 
Again, Praeger in his monumental Irish Topographical Botany says 
without quibble: “The presence or absence of lime is the most import-— 
ant particular in which petrology affects the distribution of plants; Be 
and in Ireland the bold grouping of the calcareous and non-calcareous ee 
rocks helps to emphasize this feature of phytogeology. . . . A kn - 
of Old Red Sandstone . . . breaking through the limestone ome of the 
Central Plain, steticlindcle produces Galium saxatile, Vaccinium . 
_ Myrtillus, Rumex Acetosella, Deschampsia flexuosa, and other _ = 3 





acteristic caleifuge species. . . . The converse case — the absence © 
calcicole species in counties poor in or devoid of limestone — is se ig 
strongly marked....A... conspicuous line of demarkation — ind , 
one of the most sitanidtiohe phytogeological boundaries in Ireland — | he 
is seen where the Central Plain limestones lie up against the ancient = 
metamorphic highlands of Connaught....Here, as we pass off the 
limestone, Habenaria intacta, Gentiana verna, Sesleria, and oe oo 
interesting plants which have wanes our companions over many 
give way abruptly : 
Why is this hae axiomatic law blindly ignored or only ee a : 
admitted by so many American physiographic ecologists and phyto- te ee 
geographers? That it is fundamental is beyond dispute, and by the ee 
English, Irish, and many other European investigators is clea y a 
as an essential factor in phytogeography; an and as someone 

recogniz » Tine 
has said, “If the English and Irish agree on it, it must be so. a io 
American physiographic ecologists and phytogeographers ee ae 
use this law as a constant guide their labors, as Dawson prop 
said, “will be to a great extent fruitless.” 

J. W. Dawson, Can, Nat. and Geol. vii, 342 (1862). na 
? Tansley, Types of Brit. Vee 144 (1911). ee 
Praeger, Irish Topogr. Bot.: Proc. Royal Irish Acad. vii. p. xxvii (1902)- - 

