President's Address. 29 
pre-existent forms of a similar type. The one rational 
explanation of this difficulty is to be found in the supposi- 
tion that the dry lands and ocean-basins have been capable 
of changing places at different periods of geological history. 
What, for example, are the two greatest biological pheno- 
mena which characterise the close of the Mesozoic and 
the commencement of the Kainozoic period? One of 
these is the apparently sudden appearance of an extensive 
Dicotyledonous flora in the Upper Cretaceous, and the 
other is the equally unheralded apparition of the numerous, 
large, and highly differentiated Eocene mammals in succes- 
sion to the small and generalised quadrupeds of the Mesozoic 
epoch. These enormous biological changes did not take 
place simultaneously, or exactly at the same point of 
geological time; and we are still without any reasonable 
explanation of them, other than that proposed nearly a 
quarter of a century ago by Professor Huxley (Anniv. Add. 
Geol. Soc. Lond., 1870), namely, that in such cases the early 
developmental stages of these apparently suddenly appearing 
eroups had been passed in some lost continent now buried 
beneath the ocean. In the case of the Eocene mammals, 
Professor Huxley suggested the North Pacific as a probable 
region for such a lost continent. In the case of the Cretaceous 
Dicotyledons, it seems not improbable that a great antarctic 
continent may, as suggested by Blanford, have served as an 
ancestral home. As supporting this view, we not only have 
the strong evidence which has been brought forward by Dr 
H. O. Forbes as to the former existence of a great antarctic 
continent (vol. iii. of Supplementary Papers of the Royal 
Geographical Society, 1893), but we also have the combined 
opinion of Professors Haddon, Sollas, and Cole, that “as our 
knowledge grows, we the more distinctly see in Australia 
and its islands the ruins of a great southern continent, 
fractured and submerged, possibly during the great Alpine- 
Himalayan revolutions, and now in process of resurgence, as 
the vast folds of the earth’s crust roll slowly inward upon 
the central continental mass” (7rans. Roy. Irish Acad., vol. 
XXX., part xi.). 
In conclusion, I have only to thank you once more, 
