PRESIDENTS ADDRESS. 
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superfluous for the explanation of tlie phenomena on which 
it is based, and, moreover, to be inconsistent with the evidence 
which they give. That Australia was once united AN-ith Asia, and 
that in Mesozoic time, is certain ; and that New Zealand was 
joined about the same time by way of N. E. A.ustralia, or New 
Caledonia, is very probable. But that Africa and Australia were 
ever united, except as outliers of an Antarctic continent, is quite 
contrary to the conclusions fairly drawn from the facts of the 
case, that is to say, the resemblances and dissimilarities of the 
fauna and flora. 
I am not sure that T understand what is meant by the “ falling 
in” (§4-5-6) of vast regions of the earth’s surface; but I am sure 
that the arguments for the general permanence of continental and 
oceanic areas as such are too strong to be quietly disregarded. 
One must also demur to the supposed Glaciation of the supposed 
Continent (§ 8). In order to theformation of permanent ice, whether 
in the form of isolated glaciers or of ice sheets (which are phe- 
nomena differing only in degree) these three combined conditions 
are requisite: (1) Dry land (or at best exceedingly shallow water). 
(2) High latitude, or high land. (3) An abundant .snowfall. 
Now it is assumed that there was here in the Mesozoic period 
such a dry land uniting 8. Africa, India and Au.stralia. But of 
this there is no sort of proof. High latitude is certainly wanting, 
and even the horizontal formations which are in evidence show 
that at least where they were in making there was no general 
glaciation. Moreover, the veiy extent of the hypothetical conti- 
nent is fatal to the hypothesis of an extended ice sheet, since, 
excej)t where very high mountains occui-, the interior portions 
of all continents receive a veiy restricted rainfall in comparison 
with the coasts. 
I cannot bring myself to entertain this tln^ory of a vast glaciated 
continent, at any rate in latitudes so low and on botli siiles of the 
Kquator. And yet such a tlieory almost necessarily follows from 
the h}'pothetical synchronism of theTalchirs, the Ke<'a conglomer 
ates and lyjwer Marine (Jhicial l>cdH. But when any hypothesis 
