above. As investigations have been extended to distant regions of the earth, more especially to South America, South Africa, Australia, New Zealand, and India, other combinations of beds have been brought to light, showing the total absence of almost two-thirds of the grand series represented on the ordinary geological sections of Europe. Again, instead of finding beds indicating distinct creations, as assumed at one time, the formations present the appearance of a gradual transition of one variety of fossiliferous beds into another as the rule, and those indicating apparent distinctions as the exception. Daily researches show that no real breaks exist between the remains of one formation and another, as was once supposed. We now learn that those forms of animal life which roamed over parts of the earth before man came to encroach and exercise dominion over them, were not destroyed before his arrival, but continued to co-exist with him, though in other localities, until the time came when they were to make way for man and domestic animals more suited to new conditions of life and to man's requirements.

The

Let us commence in the South, and reflect on the general character of the sedimentary deposits of Chili, Australia, New Zealand, and Tasmania in the south temperate zone. Chili is covered with a great thickness of gravel and sand-beds, in which are found marine remains of existing species. plains of Patagonia present the same appearance: nothing but thick beds of gravel deposited on the edges of the primary crystalline rocks, as is seen by a transverse section from Rio Santa Cruz to the base of the Cordillera, and in another on the Rio Negro. Beds of recent shells are found as high as 1,300 feet from the level of the Pacific along this coast; and the apparent freshness of the shells indicates that all these deposits are comparatively of very recent date.

In the south of Australia, Tasmania, and New Zealand, are found some carboniferous strata of inferior kind and very limited area. These are deposited on the broken edges of the primary slate. The general superficial deposits are composed of loose gravel and sand, partially cemented here and there by ferruginous matter. These beds contain the same kind of shells as those now seen on the coast, and the bituminous beds inclose fern-trees with leaves of the same character as those now growing on the banks of the Yarra Yarra river and in Tasmania. In Equatorial America the sedimentary beds are better developed, and more numerous than in the south, and they can be examined on their escarpment from the plains of Mariquita to the plains of Bogota; that is, from about 800 feet to 9,000 feet above the level of the sea,

The plains of Mariquita are more or less covered with thick beds of gravel, in which are found fossil trunks of coniferæ, fern-trees, corals, and the remains of crocodiles, similar to those now flourishing in that zone. The old sedimentary beds resting on the primary base contain deep-sea shells and corals, similar to those seen along the beach on the Chilian coast. As we ascend the series, we find there seams of coal, containing in the inter-stratified black shale impressions of fern-leaves, but not very abundant. Above these are argillaceous beds inclosing a variety of shells and the remains of fishes. On these, again, are deposited several calcareous beds containing fossils in abundance, such as ammonites, hamites, &c., some of which were described and figured in the Journal of the Geological Society by the late Professor Forbes in 1844. These fossils were collected in situ, and presented to the Geological Society by me in 1843. Amongst them were eight new species. Finally, the upper part of this great sedimentary formation forms the plains of Bogota, where we find again deposits of sand and gravel containing the relics of gigantic ammonites and oyster-shells. I examined the eastern flank of this branch of the Andes to the sources of the rivers Orinoco and the Amazon, and found very extensive beds of similar character to those seen on the other side; but all their organic contents, with the exception of the ammonites and hamites, were of the same description as those now existing on the coast of South America. I have obtained from white clay seams, impressions of leaves with their green and yellow colours partially preserved, which indicates that the formation could not have been of great antiquity. As we proceed northward, we find the sedimentary beds much more developed than they are in the south, and containing tropical remains, even in high latitudes. If we take Nova Scotia, for example, we find the lower beds enclose only a few deep-sea shells, somewhat similar to those still living in the south. These are covered by the carboniferous beds, in which are entombed tropical vegetation, such as fern-trees, calamites, &c., with reptiles of the existing tropical character; and on these coal-seams, again, are various beds of sandstone-clay and gravels.

I need not dwell further on this subject, as I trust I have sufficiently shown that, although the order of the sedimentary beds is never found inverted, their development in different countries is not the same; and the periods of their deposition have been very variable, and that, therefore, they cannot be correlated as to their ages.

THE FORMATION OF THE PRIMARY ROCKS.

The preceding observations refer exclusively to the formation of the sedimentary beds, in which organic remains are enclosed. I shall now proceed to describe the fundamental crystalline rocks, on which the sedimentary rocks have been deposited, and in which there are no organic remains.

On reference to the ordinary geological sections, it will be observed that the primary crystalline rocks, which have a more or less laminated structure, such as the gneiss and argillaceous schists, are represented as sedimentary beds, like the superincumbent mechanical deposits; and their general vertical position has been attributed to a tilting action produced by upheavals, &c. During my residence and travels near equatorial America from 1834 to 1842, and again from 1844 to 1848, I had an opportunity of inspecting, surveying, and carefully studying the true character of this vertical structure of the fundamental crystalline rocks, in ravines, and in natural sections, from the surface to 3,000 feet deep. I then discovered that this structure did not arise from the subdivision of sedimentary beds, but had originated from a semi-crystalline action of the primary base upwards, in the direction of the grain; and that vertical cleavage planes gradually and imperceptibly became developed in the subterranean base during the changes and the transitions of the granites into the schistose rocks. I further found, by very extensive surveys across the three branches of the Andes, and for some hundreds of miles from south to north, that this structure was not only more or less vertical, but that it had also a meridional bearing. Having fully satisfied myself of this great fact, which, as far as I was then aware, had not been noticed before, I referred to the observations of others, thinking that such a striking phenomenon could not have escaped attention.

I naturally concluded that if such great facts as this vertical and meridional order in the structure of the primary rocks had been observed, the subject would have been pursued, and some hypothesis founded thereon. On referring to geological works, I found the following observations:

Von Buch remarks that "the structure and cleavage-planes of the laminated granite, gneiss, and schist run in a south and north direction, in a position deflecting little from the perpendicular, in Norway, Sweden, and Finland. The same

order of structure was observed by M. Boué in Auvergne, and in many parts of Spain, Portugal, and Africa."-"When I arrived on the coast of Venezuela," says Humboldt, "and

passed over the lofty littoral chain and the mountains of granite gneiss that stretch from the Lower Orinoco to the basin of the Rio Negro, and the Amazon, I recognized again the most surprising parallelism in the direction of the beds. (crystalline bands); that direction was from S.S.W. to N.N.E."

During my survey of the Isthmus of Panama and Veraguas, where the same vertical structure is observed, the Californian gold discoveries were made. American geologists surveyed that gold region, and in their official reports I find the following observations:

"The auriferous gravel and clay are deposited on the edges of the primary slate rocks. The fundamental rocks are composed of bands of granite, chloritic and micaceous slate, and have been traced running on their edges in a north and south direction for hundreds, of miles."

On my arrival in Australia in 1852 I surveyed a very large area of the gold districts, and found the same order of structure in the primary rocks as I had observed in South America and other places. I then published a pamphlet, with illustrated sections of the vertical and meridional structure of the Australian rocks, which was much appreciated by the golddiggers. But I shall quote from others who have travelled in Australia, though not geologists, this further account of the general appearance of the exposed crystalline rocks of that country :

all perpendicular.

"A great portion of the Australian quartz ridges," says Mr. W. Howitt "runs from north to south over the hills of the gold regions. The clay slates and other rocks are Some action has taken place which has left them standing edgeways. They are always true to the north and south direction, and are nearly as good as a compass where they prevail; and you may trace them for twenty or thirty miles at a stretch, and, no doubt, they extend across the colony."

The official reports of the Gold Commissioners of New South Wales furnish similar descriptions. They all agree in representing the structure of the primary rocks as more or less vertical, and with a uniform bearing north and south. I therefore venture to maintain that the crystalline rocks have not been formed in beds, like the superincumbent sedimentary deposits, but that they have been produced by a semi-crystalline action under the influence of some universal power, which has given them the order of structure which they now present; and which is plainly exhibited in all deep natural sections of all the crystalline rocks in all parts of the world.

I communicated these results of my geological researches in

South America to the Fellows of the Geological Society in 1843, accompanied with large sections of the Andes. I then showed, by means of real geological sections, that the primary slates were not sedimentary beds, but the result of a semicrystalline action, and that the structure presented a most beautiful geometrical order; that the crystalline rocks were ever active, and that the whole series crystallized from water, and did not present any indication of igneous action or dry heat. These views appeared so novel at the time that but few considered them worthy of attention. I then published the results of my investigations under the title of "Geology and Magnetism," so as to place them on record.

In 1850 I again, on my return from South America and the Isthmus of Panama (which I had been surveying), read a paper at the Geological Society, reiterating my former opinions, on the structure of the primary rocks and their aqueous character. An abstract of the paper was published in the Journal of that Society. My views were again strongly opposed, but more especially as regards the aqueous nature of the granite. I then saw it was useless to bring forward such geological facts in opposition to the prevailing igneous theory. Nevertheless, I again brought the subject forward in a long paper, with abundance of illustrations, before the geological section at the Meeting of the British Association at Glasgow in 1855; also in the Institution of Civil Engineers, where it gave rise to a discussion, which was prolonged for three evenings. This paper and my general views were much appreciated by mining engineers, who were acquainted with the true character of the rocks below. About that time, or soon after, Messrs. Daubrée and Bischoff made known their observations on hydrothermal action, or the influence of water in the formation of rocks. The result of their investigations was that the minerals which enter into the composition of granite were admitted not to have been formed by crystallizing from a state of fusion, but that they have been derived from liquid solutions, or formed in the wet way.

Professor Ramsay was one of the most determined opponents of my views regarding the aqueous nature of the granite. It is but justice to that gentleman to state that, in complimenting Messrs. Daubrée and Bischoff on the result of their investigations, when President of the Geological Society in 1862, he remarked that "he could not pass over the papers and observations of one of their own members (Mr. Hopkins) on

* Geology and Terrestrial Magnetism. By Evan Hopkins, C.E., F.G.S., (Lond.: Taylor & Francis, Red Lion Court, Fleet Street.)