126 THE ROYAL SOCIETY OF CANADA 
iferous Time; but this postulated cause seems to have no weight when 
we know that evidences of glacial conditions in Cambrian Time have 
been shown to have existed in Norway and China, millions of years 
before the Carboniferous Age. The presence of Warm-Temperate 
floras in Arctic regions in Carboniferous and early Tertiary times seems 
rather to have been due to warm marine currents which in those periods 
obtained free access to the Arctic ocean. 
Of the upper Carboniferous vegetation M. Naumayr says* “In 
so far as regards the character of the flora we really know nothing of 
the temperature required for Calamites, Lepidodendra, Sigillaria and 
other extinct types,” and Professor Judd has said,f “Just as little 
reason is there for inferring that Sigillarids, Lepidodendrids and Cala- 
mites could only have lived in tropical jungles as there is for the once 
popular notion that they flourished in an atmosphere supplied with 
a very exceptional proportion of carbonic acid!” Conifers grow now 
in very severe climates and only the Tree ferns really indicate warm 
climatic conditions. At present their chief development is in the 
tropics . . . but we do not know that this was equally the case in 
former ages; in the Carboniferous the highest division of the Vegetable 
Kingdom, now so dominant, the Flowering plants, were either non- 
existant, or was only sparsely represented by a few early forms, and 
it is by no means improbable that its types in their gradual extension, 
have exterminated the Tree ferns in the colder regions to which they 
formerly extended.” The argument for a warm climate drawn from 
the great thickness and extent of coal seams is assailed, and it is shown 
that luxuriant vegetation is by no means a proof of tropical conditions. 
Naumayr further says:—“From the facts bearing on the climate of 
the Coal-measure period it is abundantly manifest that everything runs 
counter to the assumption of a uniform and warm terrestrial climate 
from the equator to the poles”. A. C. Seward has remarked that “a 
more careful comparison of Carboniferous plants from different countries 
and latitudes shows that the uniformity of vegetation of that period 
does not appear to have been quite so striking as has frequently been 
asserted.” 
In an address of Mr. T. V. Holmes before the Geologist’s Associa- 
tion (London)f in speaking of the similarity of widely separated coal 
plants, suggests “the significance of this does not appear to be great 
if we remember that these are the representatives of floras that grew 
under this head, the writer is indebted to professor A. C. Seward’s essay on “Fossil 
plants as tests of Climate’? London, 1892). 
tJ. W. Judd, Presidential Address before Geol. Soc. 1888 p. 72. 
{Presidential Address before Geologist Ass’n. 1891. 
