Feb. 24, 1870] 
NATURE 
443 
Paleozoic to the Mesozoic formation, appears to me to be 
hardly more credible ; to say nothing of the indications of the 
existence of Dinosaurian forms in the Permian rocks, which 
have already been obtained. 
For my part I entertain no sort of doubt that the reptiles, birds, 
and mammals of the Trias are the direct descendants of reptiles, 
birds, and mammals which existed in the latter part of the 
Palzeozoic epoch, but not in any area of the present dry land 
which has yet been explored by the geologist. 
This may seem a bold assumption, but it will not appear un- 
warrantable to those who reflect upon the very small extent of 
the earth surface which has hitherto exhibited the remains of 
the great Mammalian Fauna of the Eocene times. In this respect 
the Permian land vertebrate Fauna appears to me to be related 
to the Triassic, much as the Eocene is to the Miocene. 
Terrestrial reptiles have been found in Permian rocks 
only in three localities ; in some spots of France and recently of 
England, and over a more extensive area in Germany. Who 
can suppose that the few fossils yet found in these regions give 
any sufficient representation of the Permian Fauna? 
It may be said that the Carboniferous formations demonstrate 
the existence of a vast extent of dry land in the present dry 
land area; and that the supposed terrestrial Palceozoic vertebrate 
Fauna ought to have left its remains in the coal measures, espe- 
cially as there is now reason to believe that much of the coal was 
formed ondry land. But if we consider the matter more closely, 
I think that this apparent objection loses its force. It is clear 
that during the Carboniferous epoch, the vast area of land which 
is now covered by coal measures must have been undergoing a 
gradual depression. The dry land thus depressed must, there- 
fore, have existed, as such, before the Carboniferous epoch—in 
other words, the Devonian times—and its terrestrial population 
may never have been other than such as existed during the 
Devonian, or some previous epoch, although much higher forms 
may have been developed elsewhere. 
Again, let me say that I am making no gratuitous assumption 
of inconceivable changes. It is clear that the enormous area of 
Polynesia is, on the whole, an area over which depression has 
taken place to an immense extent. Consequently a great con- 
tinent, or assemblage of sub-continental masses of land, must 
have existed at some former time, and that at a recent period, 
geologically speaking, in thearea of the Pacific. But if that 
continent had contained mammals, some of them must have 
remained to tell the tale; and as it is well known that these 
islands have no indigenous A/ammadia, it is safe to assume that 
none existed. Thus, midway between Australia and South 
America, each of which possesses an abundant and diversified 
Mammalian Fauna, a mass of land, which may have been as large 
as both put together, must have existed without a Mammalian 
inhabitant. Suppose that the shores of this great land were 
fringed, as those of tropical Australia are now, with belts of 
mangroves which would extend landwards on the one side, and be 
buried beneath littoral deposits on the other side, as depression 
went on; and great beds of mangrove lignite might accumulate 
over the sinking land. Let upheaval of the whole now take place, 
in such a manner as to bring the newly emerging land into con- 
tinuity with the South American, or Australian, continent ; and, 
in course of time, it would be peopled by an extension of the 
Fauna of one of these two regions—just as I imagine the Euro- 
pean Permian dry land to have been peopled. 
I see nothing whatever against the supposition that distribu- 
tional provinces of terrestrial life existed in the Devonian epoch, 
inasmuch as M. Barrande nas proved that they existed, much 
earlier. I am aware of no reason for doubting that, as regards 
the grades of terrestrial life contained in them, one of these may 
have been related to another as New Zealand is to Australia, or as 
Australia is to India, at present. Analogy seems to me to be 
rather in favour of, than against, the supposition that while only 
Ganoid fishes inhabited the fresh waters of our Devonian land, 
Amphibia and Reptilia, or even higher forms, may have existed, 
though we have not yet found them. The earliest Carboniferous 
Amphibia now known, such as Anthracosaurus, are so highly 
specialised, that I can by no means conceive that they have been 
developed out of piscine forms in the interval between the 
Devonian and the Carboniferous periods, considerable as that is. 
And I take refuge in one of two alternatives. Either they 
existed in our own area during the Devonian epoch and we have 
simply not yet found them ; or, they formed part of the popula- 
tion of some other distributional province of that day; and 
only entered our area by migration, at the end of the Devonian 
epoch. Whether Aeftilia and Mammalia existed along with 
them is to me, at present, a perfectly open question, which is 
just as likely to receive an affirmative, as a negative, answer from 
future inquirers. 
Let me now gather together the threads of my argumentation 
into the form of a connected hypothetical view of the manner in 
which the distribution of living and extinct animals has been 
brought about. 
I conceive that distinct provinces of the distribution of ter- 
restrial life have existed since the earliest period at which that 
life is recorded, and, possibly, much earlier :tand I suppose, with 
Mr. Darwin, that the progress of modification of terrestrial 
forms is more rapid in areas of elevation than in areas of 
depression. I take it to be certain that Labyrinthodont 4m- 
phibia existed in the distributional province which included 
the dry land depressed during the Carboniferous epoch: and 
I conceive that, in some other distributional provinces of that 
day, which remained in the condition of stationary, or of in- 
creasing dry land, the various types of the terrestrial Sawrop- 
sida and of the M/ammalia were gradually developing. 
The Permian epoch marks the commencement of a new 
movement of upheaval in our area, which attained its maxi- 
mum in the Triassic epoch when dry land existed in North 
America, Europe, Asia, and Africa as it does now. Into this 
great new continental area the mammals, birds, and reptiles, 
developed during the Paleozoic epoch, spread, and formed 
the great Triassic Arctogeal province. But, at the end of the 
Triassic period, the movement of depression recommenced in our 
area, though it was doubtless balanced by elevation elsewhere ; 
modification and development, checked in the one province, 
went on in that elsewhere ; and the chief forms of mammals, 
birds, and reptiles, as we now know them, were evolved, and 
peopled the Mesozoic continent, from which I conceive Austra- 
lia to have become separated as early as the end of the Triassic 
epoch, or not much later. This Mesozoic continent must, I con- 
ceive, have lain to the east, about the shores of the North 
Pacific and Indian Oceans ; and I am inclined to believe that it 
continued along the eastern side of the Pacific area to what is 
now the province of Austro-Columbia, the characteristic Fauna 
of which is probably a remnant of the population of the latter 
part of this period. 
Towards the latter part of the Mesozoic period, the movement 
of upheaval around the shores of the Atlantic once more re- 
commenced, and was very probably accompanied by a de- 
pression around those of the Pacific. The Vertebrate Fauna 
elaborated in the Mesozoic continent, moved westward and took 
possession of the new lands which gradually increased in extent 
up to, and in some directions after, the Miocene epoch. 
It is in favour of this hypothesis, I think, that it is 
consistent with the persistence of a general uniformity 
of the directions of the great masses of land and water. 
From the Devonian period, or earlier, to the present day, 
the four great oceans, Atlantic, Pacific, Arctic, and Antarctic, 
may have occupied their present positions, and only 
their coasts and channels of communication have under- 
gone an incessant alteration. And, finally, the hypothesis 
I have put before you requires no supposition that the rate of 
change in organic life has been either greater, or less, in ancient 
times than it is now; nor any assumption, either physical or 
biological, which has not its justification in analogous phe- 
nomena of existing nature. 
I have now only to discharge the last duty of my office, 
which is to thank you, not only for the patient attention 
with which you have listened to me so long to-day ; but also 
for the uniform kindness with which, for the past two years, 
you have rendered my endeavours to perform the important, 
and often laborious, functions of your President, a pleasure, 
instead of a burden. AS Isl Inbopor sy 
SOCIETIES AND ACADEMIES 
LONDON 
Royal Society, Feb. 17.—The following papers were read : 
“‘ Account of the Great Melbourne Telescope from A pril 18¢8, 
to its commencement of operations in Australia in 1869.” By 
Albert le Sueur. The author stated that the building in which 
the telescope is placed is rectangular, 80 feet long meridionally 
by 25 wide, with walls 11 feet high. Of the meridional length, 
the telescope-room occupies the north 40 feet ; the next 12 feet 
