RELICS OF THE PERMO-CARBONIFEROUS ICE AGE. 29 
geological climates becomes more thoroughly investigated 
such may be found to result from a combination of several 
different factors, both general and local. 
It has already been pointed out that the Western 
Australian Permo-Carboniferous beds were deposited in 
the same great marine area as that containing the corres- 
ponding strata of India, and that from the similarity of the 
organic remains there must have been more or less free 
communication between the two localities during this geo- 
logical epoch. This fact has some bearing upon the question 
of the permanency of ocean basins. 
There seems to have been during the period immediately 
following the ice age, which has just been described, a land 
connection between India and South Africa, although it 
would not seem necessary for an explanation of the distri- 
bution of the Glossopteris flora that the whole of the Indian 
Ocean formed part of one uninterrupted continent at one 
time. 
In Cretaceous times there was a land connection be- 
tween South Africa and India across the Indian Ocean by 
way of the Maidive and the Mascerene Islands. Even 
at the present time traces of this barrier can be detected, for 
the north-west portion of the Indian Ocean appears to be 
cut off from the main ocean basin by a shallow belt, ex- 
tending from the Seychelles to the Maldives, which latter 
are connected by comparatively shallow straits with Mada- 
gascar and South Africa, and the Maldives with India, 
the Seychelles and the Comoro Islands being as it were 
stepping-stones yet unsubmerged. 
So far, therefore, as different lines of enquiry carry us, 
it is quite clear that the northern portion of the Indian 
Ocean was bridged by land which connected South Africa 
and India up to Cretaceous times, and this connection seems 
to have broken up into islands during the Tertiary period. 
In other words, what is now a broad and deep ocean was for 
a long geographical period occupied by land ; and the 
ocean bottom between India and South Africa has sunk 
to its present depth since the Cretaceous Period. 
Conclusion. 
In bringing to a close what has, I feai, been a moie oi 
less dreary recapitulation of ascertained facts, I would just 
like to recall to your recollection the memorable words of 
the Astronomer La Place, which in my opinion form a fitting 
termination to the contribution to the glacial geolog} of 
Western Australia, which it has been my privilege to lay 
before vou : — 
“ What we know is but little ; what we do not know is 
immense.” 
