334 PROCEEDINGS OF SECTION D. 
of continents has been most unstable, and can in no way be 
regarded as permanent during the course of geological his- 
tory.” He goes on to point out that “most probably the 
ocean basins in Paleozoic times were not so deep as they are 
now ; that numerous islands existed in them, and, possibly, » 
these former land-masses now form the bases of the groups 
of oceanic islands, wholly consisting, as far as we can see, of 
erupted rocks.” In the gradual evolution of the surface- 
features of the planet, he thinks that ‘“ Continental land 
appears, on the whole, to have become more compact, nore 
circumscribed, and higher, while the ocean hasins have be- 
come more shut off from each other, and deeper.” But, 
although the outlines and extent of the continental lands 
may not be permanent, yet there is reason to believe, he 
remarks, “That the areas within which the present conti- 
nents are situated are areas within which continents hava 
been torn down and built up again since the dawn of geo- 
logical history; while similar revolutions have not taken 
place in the abysmal or pelagic area of the ocean basins to 
anything like the same extent.’’ The faunal and floral re- 
semblances between the three southern lands has been noted, 
as you are aware, by all naturalists who have studied the 
subject ; and a large number of authors heve called to their 
aid, by way of explaining the facts, a greater extension of 
these lands in a southerly direction, accompanied by a more 
extensive land-surface across the Antarctic region, at a 
period probably as late as the Mesozoic, when the climate 
was considerably milder than at present. 
The flood of biological evidence in favour of an Antarctic 
continent has become extremely strong since it was first 
mooted by Hooker, to explain the present flora of Tasmania 
and its resemblance to these southern lands. It has been 
supported by Rutimeyer, and later by Captain Hutton, who 
was the first to attempt to correlate biological and geological 
evidence in its favour, although in recent years he has seen 
reason to considerably modify his views on the matter. The 
continent has received support from Blandford, on geo- 
graphical and distributional grounds; from Forbes, in order 
to explain the distribution of certain birds in the Chathams 
and Madagascar (he was the earliest to attempt to map 
the outlines of the continent); from Hedley. who, more- 
over, refuses to believe in so extensive a continent; from 
Spencer, as an outcome of the study of the Australian 
fauna; from Ameghino and Ortmann, as a result of their 
researches on the vertebrate and invertebrate fossils in Pata 
gonia; from Moreno, owing to the discovery of a fossil 
