The amount of river gravel left in the part of the Thames Valley on which West London is built is extraordinary. It is all round, and mostly red, and as there are no rocks like the stone which makes up most of this gravel anywhere in the modern valley, it is puzzling to know where it came from. I went to see the digging of the foundations of the new South Kensington Museum, and the great excavation, which was like the ditch of a fortress, and the stuff thrown out, which was like the rampart, was all dug in, or made of, river gravel. In this the men had found, lying higgledy-piggledy, with no two bones "belonging," quantities of bones of the beasts which used to graze on what I suppose was the Kensington "veldt," or perhaps flats by the riverside, during the time when the river's drift and brick earth was being deposited. The Clerk of the Works was much interested in these discoveries, and had caused them to be carefully collected. These were bones of the great stags then common, of the elephant, and of the primaeval horse, creatures which lived here before the Channel was cut between England and France, though not, perhaps, before man had appeared in what is now the Thames Valley, for flint implements are often found with the bones. Dr. Woodward, to whom some of the remains were taken, said that they reminded him of the great discovery of similar remains in the brick earth at Ilford, in Essex, thirty-seven years ago, when he personally saw, dug from the brickfields of that almost suburban parish, the head and tusks of one of the largest mammoth elephants in the world. These river-gravel and brick-earth buried bones are rather earlier than those found in the peat and marl. The latter belonged to creatures which, though they no longer exist in England, are still found in temperate Europe - beavers, bears, bison, and wolves. But the Thames gravel and the London clay are in places full of the bones of another, and earlier, though by no means primaeval, generation of mammals, some of which are extinct, while others are found at great distances from this country, in remote parts of the earth. Judging from the places where they are found and from the position of the bones, large animals must have swarmed all over what is now London, just as they do on the Athi plains and near the rivers and forests through which the Uganda Railway runs.

There was the same astonishing mixture of species, a mixture which puzzles inquirers rather more than it need. Hippopotamus bones are found in great numbers, and with the hippopotamus remains those of creatures like the reindeer and the musk ox, now found only on the Arctic fringe and frozen rim of the North, which lived on the same area and with them the Arctic fox. Judging from the great range of climate which most northern animals can endure, there is no reason to think this juxtaposition of a creature only found in warm rivers and of what are now Arctic animals is very strange. The London "hippo" was just the same, to judge from his bones, as that of the Nile or Congo. But the reindeer of North America, under the name of the woodland cariboo, comes down far south, and in the Arctic summer that of Europe endures a very high temperature. The Arctic fox does the same. If there were Arctic animals in Kensington and Westminster, that is no evidence that they lived in an Arctic climate. Looking over the list of bones, skulls, teeth, and tusks found, it is interesting to try to reconstruct mentally the fauna of greater London just previous to the coming of man. There were, to begin with, some African animals, either the same as are found on the Central African plains, and were found on the veldt of South Africa, or of the same families. The present condition of the country between Mount Kilimanjaro and the Victoria Nyanza shows quite as great a mixture of species. There, for instance, are all the big antelopes, rhinoceroses, zebras, lions, elephants, hyaenas, and wild dogs, and though there are glaciers on Kilimanjaro and the great mountains near the central valleys, the river running out of the Great Rift Valley is full of crocodiles and hippopotami. There is heather and, higher up, also ice and snow on the mountains, from whose tops the waters come that feed these crocodile-haunted streams. So on the London "veldt" there were lions, wild horses (perhaps striped like zebras), three kinds of rhinoceroses - two of which were just like the common black rhinoceros of Africa, though one had a woolly coat - elephants, hyaenas, hippopotami, and that most typical African animal the Cape wild dog! All these, except the elephants and hippos, can stand some degree of cold; and there is not the slightest reason why the two last may not have flourished in some deep river valley, very many degrees hotter than the hills above. To take an instance still remaining nearer to Europe than the Great Rift Valley. The Jordan Valley is very deep and very hot. Many species of birds are there found which are resident in India, and not anywhere nearer. It is a kind of hot slice of India embedded in the Palestine hills. The very large deer and immense bison and wild oxen probably fed on the same low veldt as the African animals. The bison were the same as those found in Lithuania, but far larger. Numbers of the skulls, of quite gigantic size, have been found in the brick earth. In the British Museum there is a tooth of the mammoth found in 1731, at a depth of 28 feet below the surface, in digging a sewer in Pall Mall. This Pall Mall mammoth might well figure in Mr. E. T. Reed's prehistoric series in Punch. Another tooth was found in Gray's Inn Lane. The mammoth was evidently not confined to the present region of clubland.

Besides these European and African groups of animals, a third class ranged the London plains, probably at a greater height and in a still colder temperature than the large grass-eating mammals mentioned. These creatures, whose bones are found plentifully in the drift, are now living in a country even more specialised than the African veldt. They are the creatures of the Tartar steppes and the cold plains of Central Asia. Their names are the suslik (a Central Asian prairie dog), the pika, a little steppe hare, and an extremely odd antelope, now found in Thibet. This is a singularly ugly beast with a high Roman nose, and wool almost as thick as that of a sheep when the winter coat is on. It must have been quite common in those parts, for I have had the cores of two of their horns brought to me during the last few years.

These dry bones are not made so astonishingly interesting by their setting in the gravel as are some far more ancient remains in England. The gravel is a mere rubbish-bed, like a sea-beach, in which all things have lost their connection. I was recently shown a set of fossils far more ancient, possibly not less than 2,000,000 years old, which were all found and may be seen exactly as they lay and lived when they were on the bottom of a prehistoric river which flowed through Hampshire, across what is now the Channel, over South France, and then fell into the Mediterranean. This river crosses the Channel at Hordwell cliffs on the Solent. There is the whole section, of a great stream two miles wide, with the gravel at its edges, the sediment and sand a little lower down the sides, and the mud at the bottom. On each lie its appropriate shells. Some are like those in the Thames to-day, but many more like those of a river in Borneo. They are so thick that out of a single ounce of the mud 150 little shells were obtained. In this, too, were found the tooth of a crocodile and the bones of a spiny pike, and in other masses of clay the very reeds and bits of the trees that grew there. These sedges of the primitive ages were quite charming. Even some of their colour was preserved, and all their delicate fluting and fibre, in the fine clay. One of the branches of a tree, now turned to lignite, had possessed a thick pith. This pith had decayed, and water had trickled down the hollow like a pipe. The water was full of iron pyrites, and had first lined the tube with iron crystals and then filled up the whole hollow with a frosted network of the same. There is a striking contrast between the presence and realism of these once living things still preserving the outer forms of life and the vast and inconceivable distances of "geological time."