28 Proceedings of the Royal Physical Society. 
passage above referred to, it is enough to point out that the 
occurrence of a “general deposit of oceanic ooze at some 
definite horizon” in our existing dry lands is a thing which, 
from the nature of the case, can never be looked for, and that 
the absence of such a deposit therefore proves nothing. I 
have endeavoured to show that we have oceanic deposits in 
the dry lands, and that, if admitted, is all that is necessary. 
CONCLUSION. 
I feel that I owe you an apology for having taken you 
over ground so well-worn and so familiar. Upon the whole, 
Iam convinced that the geological evidence at present in 
our hands is sufficient to negative the doctrine of “the per- 
manence of the ocean-basins ” as a general theory, and I am 
confident that in the progress of time this evidence will be 
largely augmented. As it is, I think we are fully warranted 
in believing that portions of what are now masses of dry 
land have at one time constituted parts of the floor of a deep 
ocean, and have been covered by water of from 1000 to 3000 
fathoms in depth. We have also much evidence to show 
that areas now occupied by broad and deep expanses of 
ocean have been once in the condition of dry land. The 
evidence in favour of this latter proposition is largely based 
upon considerations drawn from the geographical distribution 
of animals and plants, and I have purposely refrained from 
entering into this branch of the subject. Not only would it 
have greatly lengthened this address—already unduly pro- 
longed—but the bearings of the distribution of living beings 
upon the doctrine here in question have been very fully, and 
most ably, discussed by Dr W. T. Blanford in the Anniversary 
Address to the Geological Society of London for the year 
1890. 
There is, however, one broad consideration based on the 
ascertained facts of Paleontology, to which I must allude for 
a moment. One of the great stumbling-blocks to evolutionists 
has always been the presence of great gaps in the palzeonto- 
logical record, and the sudden appearance of large groups of 
animals or plants without any traces, or but slight traces, of 
