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supplied by the shells of the period. Some of the largest of these may be seen in our national museums in London. Among the most remarkable is the beautiful nautilus, a genus of shells none of which now live in the British seas. There are now only two living species of nautilus known, and they inhabit the seas of China, India, and the Persian Gulf.* Yet, at the period of the London Clay, and in the waters which then occupied the site of the great City, there existed vast numbers of the nautili, belonging to no less than seven species. Let this serve to remind us again that,

Where the long street roars, hath been

The stillness of the central sea !

Some specimens of these beautiful shells, figured in treatises as Nautilus imperialis, are seven or eight inches in diameter. All the nautili of the London clay are now extinct species.

Not only do the reptiles, mammals, and shell-fish found in the clay of our London environs prove to us the former existence of a climate in these latitudes which we have now to seek much nearer to the tropics. The land was clothed with a varied, tropical-like vegetation. This we learn from the abundance of fossil fruits and seeds which have been discovered, especially in the Sheppey cliffs. More than one hundred species of tħese have been determined. What are the affinities to the flora of the present day?

Forty-five species out of a hundred and fourteen are those of the leguminous or pod-bearing order of plants, an order which includes not only our common beans, clover, &c., but also the liquorice and indigo plants, the tamarind, gum arabic, and many of the large and valuable timber trees of India.”

The most abundant of the fossil fruits of the London Clay are certain fig-shaped remains. “ These fossils bear a dull resemblance to the fruit of the nipat a tree allied to the palms, and now found

* Prestwich, op. cit.

+ Nipa fruticans. — Every now and then the paddles of the steamer (at the mouth of the Ganges) tossed up the large fruits of Nipa fruticans, a low stemless palm that grows in the tidal waters of the Indian Ocean,

and bears a large head of nuts.
is a plant of no interest to the com-
mon observer, but of much to the
geologist, from the nuts of a similar
plant abounding in the tertiary for-
mations of the mouth of the Thames,
and having floated about there in as

fringing in great luxurian ce the flat shores of many of the large rivers of India and of the Asiatic Archipelago."*

These, then, are some of the facts concerning the fauna and flora and climate of the London Clay period which we discuss among ourselves as we walk in our Saturday afternoon ramble at the top of this Hornsey Hill. We now pursue the subject of climate a little further.

How long is it since this tropical temperature prevailed in the latitude of London? At what period of time did these creatures, whose habitat we have been exploring, roam over the site of our metropolis, and perhaps over the very spot in the Regent's Park to which their descendants are now brought from vast distances, and at great pains and expense, as if to an ancient, ancestral home ?

No less an authority than Sir Charles Lyell himself will here speak for us. Sir Charles calls attention in one of his works to the comparatively modern date to which some of the greatest revolutions in the physical geography of Europe, Asia, and North Africa are to be referred.

Speaking of the fossil creatures which are found to-day in the London Clay, he says they existed

“Before the Alps, Pyrenees, and other mountain-chains now forming the back-bones of great continents were raised from the deep; nay, even before a part of the constituent rocky masses now existing in the central ridges of these chains had been deposited in the sea.”+

The London Clay was therefore deposited from the waters of its superincumbent sea before the Alps, the Pyrenees, and the other great mountain-chains of the present surface of the globe had any existence.

Such is the information we obtain from each other as we survey the tumbled grass-grown sea-bed before us, from our

coign of vantage" on Mount Pleasant, Hornsey, discussing the climate of the London Clay period, and the distance of time at which it pre'vailed. As we conclude our converse we take another look at the


great profusion as here till buried deep in the silt and sand that now form the Island of Shenpey.-DR. HOOKER, Himalayan Journal. See PROFESSOR OLIVER's Guide to Kew Gardens. -Nipa fruticans is to be seen

in No. VI. House at Kew (central area).

* Prestwich, op. cit.

+ Elements of Geology (1865), chap. xvi.

landscape. It lies beneath the same sun which has witnessed these wonderful vicissitudes in its history. What romance, or fable, or dream could invest the hills and plains before us with so vivid an interest as that which their actual history gives to them !

The advancing evening and the rising mists tell us that it is early autumn.

The slope sun his upward beam

Shoots against the dusky pole. We agree to reserve Highgate and Hampstead for another excursion. We leave the sight of

Hamlets brown and dim-discovered spires,
And hear their simple bell, and mark o'er all

Thy dewy fingers draw
The gradual dusky veil.

No. VII.



HE Autumnal time for sea-side visits and foreign tours has

again been with us, and has broken the long year's spell

of City life. Away from the smoky town and from homely suburban landscapes, our Saturday afternoon naturalists have been ranging on the mountain side and the sea-shore. Some of them have been fossil-seeking in the Isle of Wight, and some collecting in Alpine regions. In these their long holiday rambles the more geologically inclined have pursued for themselves those physical and zoological inquiries which our London strata have suggested to them. At the Isle of Wight and at the adjacent mainland they found the clay of our environs emerging from its inland surroundings, and abutting with other formations on to the sea-shore. The London Clay there liberates from their ancient prison-house the petrified creatures of an earlier and buried world to the light of modern day-the chambered shell of the beautiful nautilus, the teeth of the dreadful shark, and the other vestiges of a pre-Adamite earth which there abound. And even in Switzerland the companions of our Saturday afternoon rambles are tracing in the rocks around them the relative age and history of our London fossil zoology, and turning their Middlesex rambles to account. On the flanks and summits of the Alps they are verifying for themselves the statement we lately so intrepidly put forward. “This London Clay," we said, in our last reported ramble, “this common-place and dull-looking soil, which we make so subservient to our uses, belongs to an older surface of this our world than the Himalayas, the Carpathians, the Pyrenees, and the Alps. It was deposited where we now find it, and where its parent sea has left it, before these lofty mountain chains of Asia and Europe appeared on the face of the earth. Those Alpine ranges, with all the picturesqueness and glamour which invest them, and which fascinate so many of our holiday tourists, are younger monuments of Time than that old and familiar sea-bed on which our metropolis is built, which we daily see dug up in our environs." Thus we spoke on our Hornsey ramble, and thus we moralised. And now what is the evidence to be adduced for a statement and calculation so bold ? What is the nature of the testimony which our fellow-naturalists are now obtaining for us, and which is required by the practical mind ? In brief it is this : Our companions who are climbing the Alps are already aware that the mountains and erupted hills of our own land contain in their mineral composition and structure the fossil remains of that older soil which they bore up with them as they emerged from subterranean depths, broke through the surface of the earth, and in a course of successive elevations attained to their present stature on the Alps. They will look into the sides or summits of the mountains for traces of the older marine strata through which they also, in a similar way, have been erupted. And they may find such traces in abundance. Should they mount the Diablerets, one of the loftiest of the Swiss Alps, our companions may find, at a height of 10,000 feet above the sea, those coin-like shells which geologists call nummulites—the petrified creatures of a time just subsequent to that of the London Clay. Even at this great height these shells from a sea-bed below-nearly coeval with the sea of the London Clay—enter bodily into the structure and constitution of the mountains. And these are the evidences our fellow-ramblers require. They show that the Alps, like other mountain

have borne


with them into the clouds memorial masses of the sea-bed strata through which they were upheaved. They tell the wondrous tale of the sequences and revolution in the earth's physical geography ere any human hydrographer was living to record them. And thus we discover the link which binds the

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