IOO THE AMERICAN NATURALIST. [Vor. XXXV. 
says: ‘Breeders of animals and those acquainted with zoó- 
logical gardens know perfectly well that it is much easier to 
keep a northern species in a southern climate than a southern 
species in a northern one." Similarly he returns time and 
again to the curious delicacy of Arctic plants in botanical 
gardens as a proof that their presence in central Europe dur- 
ing glacial times is no evidence of an Arctic climate. He even 
adduces the fact that Dryas octopetala, one of the most typi- 
cally Arctic plants, grows wild in profusion on the coast of 
Galway, in Ireland, at sea level, as strengthening “the view, 
not only that the Alpine flora is of preglacial origin, but that 
the climate of Europe during the glacial period was mild." 
That the Arctic and Alpine floras survived the glacial 
period there is but little reason now to doubt, but that con- 
clusion is not inconsistent with an Arctic climate in which all 
these plants even now flourish. But from this admission to 
the assumption that the climate was mild is a long cry and the 
two conclusions are not logically connected. Much less is the 
inference justified, which Dr. Scharff evidently draws, that 
the animals and plants which we now find characteristic of the 
Arctic regions originated during the glacial period during the 
mild climatic conditions and afterwards were driven off into 
the Arctic or the Alps by more vigorous invaders from Siberia 
accommodating themselves to the much severer climate. With 
regard to the plants, here are Dr. Scharff's own words (p. 239) : 
“This fact [7.¢., the difficulty of wintering these plants in the 
Botanical Gardens] suggests that the Alpine and Arctic plants 
really did not originate in countries with cold temperatures. 
They probably made their first appearance long before the 
glacial period — perhaps in early Tertiary times — chiefly in 
the Arctic regions, which at that time had a mild climate. 
They have since become adapted to live in cold countries 
where they flourish, provided they receive sufficient moisture 
in the summer, and are protected from severe frost in the 
winter by a covering of snow." Apart from the fact that this 
theory is diametrically opposed to his own idea of the difficulty 
of southern species to accommodate themselves to a northern 
climate, as expressed above, both views, and in fact the whole 
