609 
off. The generic and specific distinctions between the marsupials and the wingless birds of 
the Old and New Worlds and of Australia and New Zealand may have arisen during 
the progress of migration, and may have been further developed by the insulation which 
Australia and New Zealand subsequently attained. 
The extinction of the same fauna, which had a, geologically speaking, brief 
existence in Australia, has been accounted for by Professor Owen and Professor Tate 
by the intervention of Man; and by the late Mr. C. S. Wilkinson by the supervention of 
the present arid climate on a period of heavy rainfall, which there is evidence to show 
occurred, after Pliocene times.* Mr. Wilkinson argued that heavy rainfall and con- 
sequent luxuriance of vegetation were necessary for the support of the numerous and 
in some cases gigantic animals of which we have now only the fossil bones. Darwin 
has, however, shown f in the most striking manner that the regions which in the present 
day support the largest and most numerous quadrupeds are by no means those which 
are most remarkable for luxuriance of vegetation ; nor, conversely, are the regions now 
most characterised by luxuriance of vegetation the favourite haunts of large animals. 
As for the intervention of Man, it will be seen in a succeeding page that the evidence 
in favour of his existence in Australia coeval with the extinct Post-Tertiary Fauna is at 
least doubtful. 
I do not mean to advance a thesis which I am prepared to defend against 
all comers, when I suggest that the extinction of the Post-Tertiary Mammalia, &e., may 
have had something to do with the subsidence afterwards referred to,J but simply draw 
attention to a factor which appears to have been overlooked. It is not unreasonable 
to suppose that changes of climate followed, on the subsidence of the land, sufiiciently 
great to have a disastrous effect on the now extinct fauna. It is also possible that 
when the shores of the G-reat Australian Bight were ground down by ice, the climate 
may have been too rigorous for their existence even on the Darling Downs and the 
tropical portions of Queensland. 
CAVES. 
None of the Caves which penetrate the limestones of Queensland have yet been 
systematically explored. They may yet prove as interesting for their imbedded organic 
remains as the W ellington Cave itself. Some of these caves may be here described : — 
The limestones of the Chillagoe District (Gympie Beds ?) are remarkable for the 
number and size of the caverns which have been excavated. I was informed by Mr. 
H. G. Livesey, of Irvinebank, who has made numerous admirable photographs of the 
scenery of this remarkable region, that at least thirty caves are already known. I 
visited, under the guidance of Mr. W. Atherton, of Chillagoe Station, the cave known 
as “ The Temple,” which occurs in one of the limestone ranges on the left bank of 
Chillagoe Creek, about two miles from the Station. Entering by a lofty opening on the 
western side of the range, we walked erect for perhaps sixty yards, and then found 
ourselves in a magnificent theatre, about one hundred feet in diameter and some eighty 
feet high. The cupola-like interior was lighted from the top by a hole which had an 
area of perhaps two hundred square feet. Tim roof was festooned with stalactites, while 
the floor was covered in places with stalagmite. Occasionally these met, forming 
long and graceful columns. But the stalactites and stalagmites were rarer than is 
2 P 
* Anniversary Address to the Royal Society of New South Wales, 2ad May, 1888. 
t Journal, Voyage of H.M.S. “Beagle” Round the World ; Chap. v. 
f See remarks on the depths of the drifts in the neighbourhood of Townsville. 
