Professor GREYWACKE, the eminent Geologist, delivered an address on Natural Petrifactions, indicating the various specimens of Ancient Fossils by which he was surrounded, and describing their formation.

The first person who threw any light upon the problem, as far as I have been able to discover, was the well-known geologist, Professor Morris.

And so definitely and precisely marked is the structure of each animal, that, in the present state of our knowledge, there is not the least evidence to prove that a form, in the slightest degree transitional between any of the two groups Vertebrata, Annulosa, Mollusca, and Coelenterata, either exists, or has existed, during that period of the earth's history which is recorded by the geologist.

Indeed, the mass of biological facts has been so greatly increased, and the range of biological speculation has been so vastly widened, by the researches of the geologist and palaeontologist, that it is to be feared there are naturalists in existence who look upon geology as Brindley regarded rivers.

The Lias of England and the Lias of Germany, the Cretaceous rocks of Britain and the Cretaceous rocks of Southern India, are termed by geologists "contemporaneous" formations; but whenever any thoughtful geologist is asked whether he means to say that they were deposited synchronously, he says, "No,only within the same great epoch."

Now suppose that, a million or two of years hence, when Britain has made another dip beneath the sea and has come up again, some geologist applies this doctrine, in comparing the strata laid bare by the upheaval of the bottom, say, of St. George's Channel with what may then remain of the Suffolk Crag.

But the moment the geologist has to deal with large areas, or with completely separated deposits, the mischief of confounding that "homotaxis" or "similarity of arrangement," which can be demonstrated, with "synchrony" or "identity of date," for which there is not a shadow of proof, under the one common term of "contemporaneity" becomes incalculable, and proves the constant source of gratuitous speculations.

In commencing these remarks, mention was made of the great obligations under which the naturalist lies to the geologist and palaeontologist.

Assuredly the time will come when these obligations will be repaid tenfold, and when the maze of the world's past history, through which the pure geologist and the pure palaeontologist find no guidance, will be securely threaded by the clue furnished by the naturalist.

I do not suppose that, at the present day, any geologist would be found to maintain absolute Uniformitarianism, to deny that the rapidity of the rotation of the earth may be diminishing, that the sun may be waxing dim, or that the earth itself may be cooling.

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 Palaeozoic epoch, but not in any area of the present dry land which has yet been explored by the geologist.

They say all this coast has strong attractions for the geologist; but what of the poet and painter?

The most important facts of geology do not require, to discover them, any knowledge of mathematics or of chemical analysis; they may be studied in every bank, every grot, every quarry, every railway-cutting, by anyone who has eyes and common sense, and who chooses to copy the late illustrious Hugh Miller, who made himself a great geologist out of a poor stonemason.

But I have only time to point out to you a few curious facts with regard to reptiles, which should be specially interesting to a Hampshire bio-geologist.

Thusto give a single instanceno man can now be a first-rate botanist unless he be also no mean meteorologist, no mean geologist, andas Mr. Darwin has shown in his extraordinary discoveries about the fertilisation of plants by insectsno mean entomologist likewise.

A manI do not say a geologist, but simply a man, squire or ploughmansees a small valley, say one of the side-glens which open into the larger valleys in the Windsor forest district.

Meantime Mr. Calhoun, who was struck by the earnestness of his views and scientific enterprise, offered him the situation of geologist and mineralogist to an exploring expedition, which the war department was about dispatching from Detroit to the sources of the Mississippi under the orders of Gen. Cass.

The cave itself is a striking object for its large and yawning mouth, but, to the geologist, presents nothing novel.

To the casual observer the rocks have the appearance of being lifted up, shattered, and overturned; but it is only the geologist who knows the vast extent of this disturbance.

* * Bishop Watson compares a geologist to a gnat mounted on an elephant, and laying down theories as to the whole internal structure of the vast animal, from the phenomena of the hide.

Professor T. Edgeworth David, C.M.G., F.R.S., of Sydney University, who was the geologist to Shackleton's party.

Prof. T. Edgeworth David, of Sydney University, who accompanied Shackleton's expedition as geologist.

He is also an eminent man of science, who has done admirable work as a geologist and a geographer.

Among Colonel Rondon's companions were Captain Amilcar de Magalhaes, Lieutenant Joao Lyra, Lieutenant Joaquin de Mello Filho, and Doctor Euzebio de Oliveira, a geologist.

MATHER, KIRTLEY F. Sons of the earth; the geologist's view of history.