Chapter XIII: The Guadaloupe Human Fossil 159 (2)

Ice, which is only solid water, has also been a powerful tool in shaping the surface of the Earth, but it has not been _always_ at work as water has. Ice now covers only a comparatively small part of the globe near the north and south poles, and mountains like those in Switzerland; but by watching what ice is doing now in these places we are able to be certain that there has been a time when it covered Scotland, Cumberland, Wales, Sweden and Norway, and nearly all North America. In watching the great “rivers of ice,” called glaciers, in the Alps, for instance, we see that they slip down from the mountains slowly, creeping on year by year, and bringing with them pieces of rock and stones. We see also where they have melted that they have been grinding the rocks beneath them with their great weight, and have cut grooves into, and scraped and polished the hardest granite. The stones underneath the glaciers have been pressed so heavily upon the rocks that they have left deep marks, and we find the same kinds of marks and heaps of stones in many mountains where there are no glaciers now. There are other things too which convince us that a great ice sheet spread over almost the whole of Great Britain. When the huge icebergs break away from the frozen shores of Greenland and North America, they often have frozen into their ice large blocks of rock, sand, gravel, &c., and when they drift into the warmer seas of the south they melt, and of course these blocks or “boulders,” as they are called, sink to the bottom. Just the same kind of boulders are found in many parts of the world, where icebergs never come now, and as they are of a different rock from that on which they lie, they must have been brought there somehow. We naturally suppose then that they were brought by icebergs. Sometimes boulders of granite have been found thus among clay, many miles from where there are any granite rocks on the surface, and there can be no doubt that they were originally frozen into an iceberg, which floated away with them and when it melted left them so far from their native place. In many of the midland and eastern counties once floated these icebergs, dropping the stones and boulders which they brought away from the Welsh, Cumberland, and Scottish mountains.

The climate of the earth must have been fearfully cold when our country was covered with ice, just as Greenland is now. Geologists suppose that there must have been more than one age of ice, and that between these ages the climate of the world was pretty much the same as at present, although it is certain that there were periods when England was much warmer, because many of the fossil plants could not have grown in a cold climate.

You will want to know whether there were any land animals living during the ice periods. It is impossible to be quite certain, but it is most likely that the mammoth was living both before and during the _last_ ice age, because its bones have been found among the earths brought down by the glaciers.

I have said all you will be likely to remember at present about the nature of the different rocks, but it will help you to understand better how they have been laid one upon the other, and how they have been moved and broken by upheaval and subsidence, if you look at the drawings on page 51.

DENUDATION.

It has often happened that some of the harder and older rocks, like granite and slate, have pushed themselves through those earths lying above them, and then the sea or a great river has washed away all the earths from one side of the rock. The rain, too, falling for thousands of years, has swept them down into the valleys and mixed them together. This is called denudation, or “laying bare” the harder rocks by washing the softer ones away from them. Those beds of pebbles on the sea shore also have been battering against the rocks for ages and very gradually wearing them away, as you can see if you watch the stones being driven into and sucked out of holes and cracks by every wave. Thus, both the loose stones and the solid rocks get polished and ground away, and Nature is always destroying and making again by turns. If this destruction went on continually without any raising of the land to make up for it, the surface of the whole Earth would in time become level; but old sea beds are always being slowly raised above the water and prepared for the growth of plants and the habitation of animals.

If you watch the little rills of water on any rainy day, trickling down a hill, or the springs which bubble up at the foot of cliffs on the sea shore, you will see an example of denudation in a small way. The earth is washed off the surface here and there, and carried down and laid up in banks in some places, and the harder ground underneath is laid bare. Little beds of stones are collected in one place, and sticks and straws and such light things in another, and this is just what has been done on a large scale in mountain regions, all over the world for many centuries.

In the uppermost sketch on page 51 you will see how the granite has been lifted up with the layers of other earth along its sides, and afterwards even layers have been deposited above; in the second there has been a great crack in the land, and a great mass of rock has subsided, and the hollow has become filled up in time with clay, and mould, and rich soil, so that some one has built a house and made a garden on it; in the third the river has cut a gorge in rocks which were once continuous from cliff to cliff, wearing away the softer earths more easily than the harder. If the Earth was cut into in different places we should find the rocks arranged in a very similar way to that in the three sketches.

BOILING SPRINGS, ETC.

In several different countries there are very strange sights, but scarcely anything is more astonishing than the fountains of boiling water which shoot up out of the ground. There are a good many of them not far from us, in Iceland, and many hundreds in Wyoming in America, and they are called “geysers.” Steam and boiling water, and sometimes mud, are thrown up by these natural fountains to a height of 200 feet—as high as the top of the spire of a church. The water must come from a great depth in the ground—perhaps many thousand feet down—where the heat is intense. This water springing up with clouds of snow-white steam, and falling all round in showers, has a most beautiful appearance. These geysers now and then throw out very little water, just bubbling up above the ground, and then travellers boil eggs and chickens and such things in them, and have a pic-nic near them. It is impossible to say how long they have lasted, but we know from history that some have been spouting out water for at least 2,000 years, and how much longer no one can tell. They may have something to do with volcanoes, because water may have found its way to the heated interior of the earth, and being converted into steam, expands and causes an eruption.

Now that we have some idea of the construction of the Earth, we must go on to the _life_ of the wonderful plants and creatures which have peopled it.

_THE VEGETABLE PART._

THE DAWN OF LIFE.

The first beams of the rising sun, and the first grey light of the morning, tell us of the coming day; but we cannot even think of the dawn of that far-off day in the Earth’s history, when no voice of man or beast was heard, and no trees or grass covered it, without solemn wonder at the immense distance that day is from us. A thousand ages are in the sight of the Creator but as yesterday, and the period of man’s existence is only a moment compared to that of the lowly creatures which built up this World for him. In the first seas and on the land nothing was heard but the rushing of waters and the roaring of the fires of volcanoes.

It is impossible to be quite certain whether the first living things were animals or plants; but I think it most likely that very simple plants grew first, and that very simple animals came after or with them. Among the first of these, or perhaps the very first, were some small animals called _Eozöon_, which means the “life-dawn animal,” and with them grew some simple plants. On the banks of the St. Lawrence river in Canada there is a great bed of rock called the Laurentian rocks, made almost entirely of the tiny remains of the “life-dawn animal,” which, when we look at them through a microscope, are found to possess nearly the same structure as some lowly organized shells living in the seas now. These rocks are found in many parts of the world besides—in Eastern America, Bavaria, Scotland, and Norway; and in some places their thickness has been estimated at thirty thousand feet, or nearly six miles, or one hundred times as thick as St. Paul’s Cathedral is high! These little creatures you see were at work over a great part of the Earth’s surface, and you may fancy how many thousands of thousands of years it took them to build up these rocks. The “life-dawn animal” is far older than the chalk-building foraminifera, and so far as we know it lived alone in its seas. There were none of the beautiful twisted _ammonite_ shell-fish, nor the shark-like fishes of the chalk seas. The eozöon was the only kind of living creature, the “lord of creation” for the time; and though storms raged in the seas it inhabited, the water was so deep that it lived on undisturbed. When you are able to use a microscope you will be able to see the traces left by these tiny animals in what is now hard stone.[1]

Life began in a very small way: there were none of the great land animals we have now; but these seemingly insignificant builders were at work so long that they made the immense rocks I have told you of. But this is not all. About this time some very simple plants grew on the land, and were carried down by the rivers and formed deep beds. After a long time these became covered up with different earths and were turned into the substance called “black-lead,” which you use in drawing pencils. But this is not really lead; it is almost pure carbon—in fact, the oldest kind of coal—so old that it will not now burn like coal, and is entirely made up of fossil plants crushed out of shape, so that we cannot now trace their forms, as we can the plants of the coal. When then you next take up a drawing pencil it will be easy to remember that the black substance which marks the paper was once a living plant, now changed by heat and pressure into almost pure carbon. As the name eozöon has been given to the “life-dawn animal,” I will give this black-lead the name of _Eodendron_, or the “dawn-plant.”[2]

Two very simple forms of life then occupied the earth and sea at the earliest time when anything at all was living, and strangely enough we use the dead bodies of both of them. We build houses of the rocks the eozöon laid down at the bottom of the sea, and the beautiful art of drawing is carried on with the carbon from the first plant life of the world—the eodendron.

I must take you away presently to the coal, and sandstone, and chalk, and show you how plants and animals gradually increased in number and size, and fishes began to inhabit the seas, and all living things were slowly going on to greater perfection; for as time went on there was a steady progress from creatures like the eozöon, which had scarcely any power of moving about, to the active, quarrelsome and greedy things like crabs and lobsters which came after them, and the gigantic ferns of the coal beds. The peaceful “life-dawn animals” drew their food from the vegetable substances dissolved in the waters, though they perhaps also lived on animals still smaller than themselves; but, by-and-by, creatures, which must have been monsters to them, swarmed in the seas and devoured their smaller companions wholesale; and in time the Earth became very much the same as it is now, a place where the struggle for life is always going on. It is certain that animals have fed upon one another from the very beginning; but this is no doubt a wise law of the Creator to prevent them from increasing too fast, as they would do if all that were born lived, and none were destroyed.

We know much less about the vegetation—the plants and grasses—of the early ages of the world than of the animals; because plants rot away faster than bones and shells, and, besides, are less likely to be found in places where they would be preserved. A dead tree might be eaten up entirely by insects, as the white ants eat up fallen trees in a short time in tropical countries, and what is left of them crumbles away to fine powder and mixes with the soil. Immense trees are thus devoured now by millions of tiny insects no longer than your thumb nail, in India and Australia. No such thing as a whole and perfect fossil tree with every twig and leaf has been found; but then the coal beds are really great forests which have been buried for so long a time that they have quite altered in appearance. Still, among these coal beds we often find the bark, fruit, stems, and branches of trees very much like firs, and ferns, and huge club-mosses, which have the same shape they had when living, though they are quite black, and burn exactly like coal.

But there were plants long before the coal forests lived, and many fossil sea weeds are found in the old sandstones and limestones in Wales and other places.[3] The Old Red Sandstone, whose position you can see below the coal in the table of succession of formations, page 42, does not give us many fossil plants, though fishes and shells are common. This rock is found in Scotland, Herefordshire, Devonshire, and Ireland, as well as other places, and is often more than 2,000 feet thick. It was not all formed in salt water we know, because many of the fossil fishes and shells it contains are fresh water kinds. It must all have been made of the pieces of still older rocks worn away by rivers and settled like a sediment in immense lakes, some of which were fresh water. Then, after the Old Red Sandstone, came a time when the limestones below the coal were laid down at the bottom of a vast sea, and here the remains of land plants are of course few. Then it seems there must have been a very long time when there were large continents all over the world raised above the seas, but not very much, and on these the forests grew which afterwards became coal fields. Until this time the plants had been mostly water weeds, reeds, rushes, and sea weeds, and it was not until England and Ireland became one continent, as they were once and covered with woods, that the great period of vegetation began.

The growth of plants was then most wonderful; but although coal is found in many different parts of the world, it was not all formed at one time, and though it is plentiful in England and Wales, Scotland, Ireland, France, Belgium, Russia, Hungary, Australia, New Zealand, China, and Borneo, it is older in some countries than in others. It is fortunate, however, that this useful material was made in Nature’s workshop in so many different countries, or it would have to be carried from one to another. The coal forests were not the same trees as we have now—oaks, elms, ashes, limes, and so on. Most of them had rather hollow trunks and splendid waving tops like ferns and reeds, though there were some like our fir-trees.

If you lie down in the long grass before it is mown, and look through the stalks and fancy yourself an inch high only, you will have some idea how the coal forest would have looked if you had lived then. But there were no human beings on the Earth then, and I do not think there were any large animals, at least none have been found in the coal itself, except in Switzerland, where a few bones of the mammoth (an ancient elephant) and of the rhinoceros have been discovered in the much newer beds of coal, and also those of a large reptile like a crocodile in the coal beds of Ohio in America.

_Fossil Tree Fern._

_Calamites._

_Lepidodendron._

_Different Kinds of Plants of the Coal Forests._]

In such immense forests insects must certainly have been plentiful, and some of the fossil bodies of beetles, dragon-flies, and spiders, have been preserved, and a few tree lizards.[4] Of course the edges of the coal forests were washed here and there by the salt sea, and there must have been some fresh water rivers and ponds, for we find both fresh and salt water shells in these beds. It was almost dark in these forests, so thickly did the plants grow together. There were enormous club-mosses close together and as high as most houses, with their leaves interlaced making a complete network to shut out the sun. But the sun which shone on the forests was warm, and the air which went through them was soft, or they would not have grown so wonderfully. Indeed, there can be no doubt that the climate of northern regions was once much warmer than it is now. A thick bed of coal was discovered by the Arctic Expedition in 1875-6 actually within five hundred miles of the North Pole, where the ice on the sea is now thirty or forty feet thick![5] The forest which formed this coal could only have grown in a temperate climate, and there are no forests there now; it is so intensely cold they could not live. There must then have been a great change in the climate of the Arctic regions since that coal was living vegetation. The few plants and mosses which can live there now are of a very different and more hardy kind than those of the coal forests.

If you look at the engraving facing page 64, you will see a drawing of one of the tree ferns with its delicate fronds which grew so abundantly in the coal forests, and there are many other plants, some like the common “mare’s tails,” or _calamites_, growing in shallow ponds and ditches now—only the “mare’s tails” or calamites of the coal forests were as high as poplars.[6] You can imagine what a splendid sight these forests of ferns, club-mosses, and “mare’s tails,” must have been, and what a multitude of beautiful insects and butterflies must have flitted about in them; but their frail bodies have almost all perished, so that we know very little of the animated creatures of the time.

Besides several sorts of coal both soft and hard there is a substance called “lignite,” which is scarcely wood and scarcely coal, of a brown colour. In fact, lignite is wood almost turned to coal, and it has helped us to learn that coal was once living wood; but it is not nearly so old as the coal. Then again there is the beautiful substance called “jet” used for making bracelets. This is a kind of fossil gum or pitch dropped from the trees while they were growing, and, though different in colour, it is much the same in kind as amber. Amber is often found with flies, spiders, and small leaves imbedded in it. When this fossil resin or gum was flowing out of the ancient pine-trees, and was quite sticky, flies settled upon it and became entangled in it, and as more of the gum flowed out they became quite covered. Then the gum dropped from the tree and hardened, and it is now found in lumps on the shores of the Baltic Sea, and in beds of sand and clay with fossil wood. It is of a beautiful bright yellow colour, and beads for necklaces and other ornaments are made out of it.

If we arrange the things we have been talking about in order, the oldest first, they would come thus: plumbago or black-lead—or, as I have called it, eodendron, “the life-dawn plant”—first, then hard coal, then soft coal, then lignite and jet, then bog oak and peat. But I must tell you something about bog oak and peat. In many of the swamps and bogs of the World the trunks of dead trees are found, which have become quite black and almost like lignite, because they have been buried so long. Thus, in the bogs of Ireland oak trees are often found, and they were most likely living when the reindeer inhabited Ireland. This old bogwood is made into beads for necklaces and other ornaments. Peat is a partly decayed vegetable substance, with beautiful little plants growing on its surface, and is really coal in its infancy. It is found all over the world more or less in wet places, and consists of the roots and stems of mosses and reeds, some of which are like the gigantic plants of the coal period, but very small in comparison. I have no doubt that in time some of these peat bogs may be turned into coal if they sink down and become covered with other earths, but at present they are all on the surface and so soft that they are dangerous to walk upon because one may sink in and be smothered.

This, as far as we can trace it, is a sketch of the history of vegetable life on our Earth. We will go back to the coal for a moment and see what the animal life of that time was. The seas of the time of the coal forests were sometimes shallow, sometimes deep, and in the limestone rocks of the oceans which separated the great continents of that time there is a record of the inhabitants of the seas. The land plants were of more than 1,000 different kinds, and there were more than 200 kinds of fishes in the waters, and corals, shells, and small crab-like animals innumerable. The fishes were fellows with terrible teeth, and their bodies were covered with strong hard scales. One of these fish was thirty feet long, and there were others of considerable size. It is curious that the fishes of this time remind one of reptiles (lizards and crocodiles), just as the birds of a future time seem to have something of the reptile about them, as you will see by-and-by.

I dare say you have remarked while reading that all the plants and animals of the early ages of the world seem to be made on a simple plan, and as the Earth grows older they become more perfect, and this is just what I want you to take notice of all through. The plants of the coal period, you have seen, were nothing like so perfect in construction, beautiful as they were, as the forest trees of the present time, neither were the animals so perfect as those living now. There has been _progress_, step by step, throughout the vegetable and animal creation; and, though many of the lower forms of the early ages exist now, there are others far superior to them which did not exist then: but all this will come in “The Animal Part.”

About the middle of the Earth’s age came the wonderful period of vegetation which gave us our coal, and after that there was a great and busy time, when huge reptiles and reptile-like birds, and then true birds, made their appearance. But that belongs to the next part of the “puzzle of life.”

If we look with astonishment at the coal forests, we may also well think of them with thankfulness. Here is the sunshine of past ages stored up for our use, and we bring it out again to warm ourselves, cook our food, make all our iron things, and drive our steam-engines! Can any romance be finer than this, that we are carried across to America and India and Australia in steam-boats driven by the “fossil sunlight” of ages and ages past, and whirled along at sixty miles an hour over iron rails by the same stored-up strength?

If you doubt this, think of living trees. Do they not live by the air and sunlight? Will they grow without these? They spread their branches and leaves to gather the warmth and light from the air, and when they are cut down and dried, and you put a match to the wood, all the old warmth and light come out again; and we know that the coal is only fossil wood. Our Creator wastes nothing. Even when there were no people living to rejoice in the sun, He thought of those people who _should_ come in time, and not one of the fiery rays of the fierce sun was lost. These mighty forests were sent to gather it, and when they had died down they sank below the surface and were covered from the air, that none of their light or heat should escape.

In such forests it is strange that there were no birds, especially as there were swarms of insects, and no doubt abundance of worms. But no bone of bird or any trace of feathered songster of these lovely groves has yet been found. Little lizards chased flies and beetles up and down the stems of the club-mosses and ferns, and larger reptiles lurked in the long damp grass under the shade. The pools and ponds were filled with curious fishes, and reefs of beautiful white coral fringed all the shores of the seas.

But the Earth was not fit for the habitation of man. The fruits of the trees were not such as he could have eaten, and their wood was not hard enough to build houses of. Still it was being got ready for him, and not a leaf waved uselessly in the bright, warm air, and not a tree fell to the ground, but it was to be turned into coal, and to come forth again one day a hard black lump, without any of its former beauty, but to give back the light and heat it had gathered from the sun ages and ages ago.

Many periods in the Earth’s history have passed since the coal period, and in every one of these the trees have been increasing in perfection, though there have never since been such great numbers of a few kinds growing. When we come to the more lately formed beds of earth we begin to find the cypress, willow, ash, oak, elm, and other forest trees which are living now. The trunks of these trees, blackened by age, lie buried in peat bogs and swamps all over Europe. The mighty Mississippi river brings down immense quantities of dead trees, and as these sink to the bottom near its mouth they are forming future coal beds. Along the coast of Norfolk and Suffolk, too, and stretching far away under the German Ocean, is an old English forest. In some places the trunks of the buried trees may be seen standing upright just where they grew. The nets of the fishermen are continually bringing up pieces of wood, roots, and seeds; and when the sea washes away the soft cliffs here the bones, teeth, and tusks of the elephant, rhinoceros, hippopotamus, and other large animals which inhabited this forest, may be seen in great numbers.

Down below the waves of ocean have these woods sunk with all their once living creatures, and though you may suppose that it must have been very long ago that they grew, they are of the same kind as those which now make the hills and valleys of England beautiful.

Sometimes a forest must sink very fast, for travellers have told us how they have sailed on rivers and lakes over the tops of sunken trees, and, looking down into the clear water, have seen the branches waving below—tall trees standing upright at the bottom, and the boats sailing over their tops!

We must now pass on to the living creatures which peopled the Earth, and their story can be told with more certainty than that of the perishable plants which clothed the surface of the ground, and, while they rendered it beautiful, also served as food and shelter for innumerable animals, and have become so useful to us as coal, lignite, black-lead, and other productions of ancient forests.

FOOTNOTES:

[1] Specimen in Table-case 15, Room V., North Gallery British Museum.

[2] The name _Eophyton_ has also been suggested for the earliest vegetable forms.

[3] Divisions A and B of Case 1, Room I., North Gallery, contain some of the oldest known fossil plants.

[4] Fossil insects in Table-case No. 14, Room V.

[5] In 81° 44′ N. latitude.

[6] Specimens of plants from the coal in Cases No. 2, 3, 4, in Room I.

_THE ANIMAL PART._

We must now go back and collect the smaller pieces of “the puzzle” which make up the animal part. The great periods of vegetation ended in our country with the coal forests, and there has been no such wonderful growth of plants since the time when the New Red Sandstone, lying above the coal, was formed; though no doubt trees and plants have since flourished, as they do now on the Earth, but not in such quantities as during the coal period.

We remember that the eozöon, “the life-dawn animal,” is the oldest animal we know of, and that it lived so long ago as when the Laurentian rocks were laid down at the bottom of the seas of that time; then in later rocks we find the burrows of sea worms in the stone, and later still simple shells with two valves like the common mussel, and other animals of a simple kind, like the corals, sponges, and star-fishes which exist now. There must have been millions of these creatures in the older limestone seas, for the rocks are almost entirely composed of their fossil shells and bodies. By-and-by a rather superior animal inhabited the seas of Wales, called a trilobite, of which you will see a picture on the opposite page. This curious animal was of the same family as the shrimps and prawns, but much larger, and he must have been a giant among the others. None of these animals had any bones, you must understand; but they had a hard shelly covering to support their soft bodies inside, and no doubt the trilobites were able to swim about very fast.[7]

_Trilobite._]

What I want you to take notice of now is the _progress_ that has been going on from the almost motionless eozöon to the shell-fish and star-fish, which could crawl along the bottom of the sea and over the rocks, to this active, quick-moving trilobite, with his great paddles. Then the next step is a very great one, when we come to animals with bones. The first of these are fishes. All the other bones are joined to the backbone, therefore all animals with bones are called _vertebrata_, which is a Latin word meaning having a backbone with joints. Now animals with bones are plainly superior to those with only shells, and when we find fishes among the rocks of Wales and Devonshire we know that we are beginning to pick up some important pieces of the “puzzle of life.” These fishes were most of them related to the sturgeon, and their bones and teeth are found in great quantities in the Old Red Sandstone rocks, just below the coal.[8]

It is not until we get above the coal into the oolite or egg-stone rocks that still larger and altogether superior animals, both of sea and land, began to increase, and this is called

THE AGE OF REPTILES.

This has been called the reptile age because there were such numbers of animals like crocodiles, lizards, and tortoises (which are all reptiles), and some of them were of immense size. For instance, there was a huge creature something like a frog, but as large as a Shetland pony, called the _Labyrinthodon_, with a great many curious teeth, and this animal has left footprints in the New Red Sandstone which have been dried and buried, we can’t tell how long, and there are the cracks made by the sun drying the place he walked over when that was soft earth. There is a drawing of some of these footsteps in the picture on the next page, and there are also the footprints of a large bird, and you can see where he walked over the soft earth and made a long line of footmarks; and if you look at the footprints of birds on the snow or mud now you will notice marks just like these. Then there is another picture of a single footprint of a large bird, and all those round dots are where rain-drops fell and left their marks in the soft earth.

(1) _Footprints of Labyrinthodon._

(3) _Footprints of Birds_, (2) _with marks of Rain-drops_.]

I dare say you will wonder how it is that these footprints have not disappeared. Well, when the animals and birds that made them had gone the marks became filled with dry sand, no doubt blown in by the wind, and then the mud dried hard, and at last it became covered with other earths and sank slowly down, just as the coal forests had done before, and remained there until we dug it up with these tracks of the birds and animals that lived then. Some of these birds must have been larger than any living now, because their footmarks are so long. None of their bones have been found yet, I believe, but plenty of the teeth and some bones of the labyrinthodon have. The real footmarks, of course, are very large, though they are small in the picture.[9]

In the great beds of Lias there are many other strange animals, and among them are two great fish-lizards called the _Ichthyosaurus_ and _Plesiosaurus_. Both of these lived in the water and perhaps came on land sometimes, and it is certain that they must have been very ferocious creatures, from their great size and sharp teeth. The plesiosaurus would be able to raise his long neck above the water and snap at some of those curious birds rather like bats which lived at the time, and of which I shall have something to say presently. Some of these fish-lizards were as large as whales, and their bodies have been so beautifully preserved in the limestone rocks that we can actually sometimes find in their stomachs the food they lived on.

_Ichthyosaurus._

_Plesiosaurus._

FISH-REPTILES.]

Now we have got to a higher order of creation still, these fish-lizards, and they remind one of the next step in progress—birds. You know that all birds lay eggs, so do almost all reptiles, such as crocodiles, lizards, and most snakes, so that they are alike in this. Then the plesiosaurus with his long neck reminds us of such birds as the heron and the swan, but he is altogether more like a reptile than either a fish or a bird. There were also huge land reptiles, which lived in the forests of the time, and must have been a terror to the smaller animals. From the bones of one of these which have been found in the oolite clays near Weymouth in Dorsetshire (the _Cetiosaurus_), we see that it must have been nearly as large as an elephant, and there are others called the _Megalosaurus_, _Dinosaurus_, &c. All these names end with _saurus_, a name taken from the Greek word meaning lizard; and you will see now why the oolite, or “Jurassic”[10] age, as it is sometimes called, is well named the “reptile age,” for these creatures swarmed on the land and in the sea. Specimens of these you can see for yourselves in the cases on the walls of the third room in the North Gallery of the British Museum, where all the fossils are collected.

But still more extraordinary animals than any of these lived at the time, and we can scarcely tell whether they were birds or reptiles, as they were something like both, but I suppose we must call them flying reptiles, and they are the nearest approach to birds that had yet existed. These creatures are called _Pterodactyles_, from two Greek words which mean “wing-fingered.” Suppose the little fingers of both your hands were a yard longer than the others, and suppose a thick leathery skin was stretched from the tips of your long little fingers to each of your feet, you would have wings something like a pterodactyl and also something like the wings of a bat. But the pterodactyl had a long neck and a long beak-like mouth, full of long sharp pointed teeth. It could not walk much I think, but it could hang itself up by its hind limbs to a tree or rock, head downwards like a bat, and must have been able to fly very strongly, with its huge leathery wings, but it had no feathers. There were swarms of these curious half lizard half bird-like animals on the land, and they were of all sizes, some no bigger than a crow, and some as large as the albatross, measuring twelve feet across their outstretched wings. Their skeletons are some of the commonest fossils in the oolite rocks, all through the great reptile age.[11]

Now you see we have come to a reptile that can fly, but, excepting for its wings and some of its bones, more like a crocodile than a bird. A little further on we find another curious animal in the oolite rocks, which is much more like a true bird than the pterodactyl, because it had feathered wings. It is called the _Archæopteryx_, which means “ancient wing,” and I have given a picture of it on the same page as the pterodactyl, so that you may compare them together. The blade-bone and “merry-thought” of this creature were exactly like those of a bird, and so were the feet and legs, which would enable it to walk easily, or perch on the branch of a tree, but the tail was long and many-jointed like that of a lizard, with a fan of feathers growing on each side of it, and short feathered wings. Then it most likely had teeth like a lizard, and there were short claws at the bend of the wings. This bird-reptile was about the size of a crow, and was the first we know of with feathers, and the limestone rock has preserved it most beautifully through all the long ages which have passed since it flitted over the land of the oolite period.[12] Later still than these, there lived in America, about the time the chalk was formed in England, two strange birds called _Hesperornis_ and _Ichthyornis_, both of which had teeth in the jaws. The former was an immense fellow like the penguin, with short wings, and the latter was about the size of a pigeon with large feathered wings.

They are finding more of these curious creatures every now and then in America. Some are without teeth, and have a horny bill like that of a real bird, and in other ways more nearly resemble living birds; still they have not lost the appearance of reptiles in their principal bones.

_Pterodactyl_ (_Wing-finger_).

_Archæopteryx_ (_Ancient-wing_).]

I have been particular in describing some of these fish-lizards and bird-reptiles; because they, or their near relations, were the principal inhabitants of land and sea from the end of the coal period to the end of the chalk, though there were of course swarms of fishes and shell-fish; but I ought to tell you that even so early as this there was at least one animal known which suckled its young ones, and this was a small insect-eating creature not larger than a rat, of the same family (called _Marsupial_) as the kangaroo of Australia, which carries its young ones in a pocket or pouch in its skin.

All this time we have been hunting for parts of “the puzzle” in those ancient oolite rocks between the coal and the chalk, and those we have found are very important. We have seen the slow progress from simple sea shells to simple fishes, and then onwards to fish-lizards and bird-reptiles with one little marsupial animal, of a far higher kind, in between, as if to tell us beforehand what more complete and perfect animals we might expect by-and-by. After the fishes we have found fish-lizards, then bird-reptiles with wings, but no feathers, and later still a bird-reptile with wing and tail feathers. How different the life of the Earth was at the end of the “reptile age” of the oolite rocks, to the far back Laurentian time when one little creature, our old friend eozöon, alone held possession of the seas!

THE CRETACEOUS PERIOD.

Now let us look into the rocks next above, and see what is to be found there. We have arrived in the Cretaceous period, or time when the chalk was formed.[13] You remember I told you you might call this “foraminifera earth” because so much of it was made up of the shells of these tiny animals, thousands of which could be put into a thimble. Whenever you make a mark with a piece of drawing chalk you rub off a number of them, and you will see what pretty little creatures they were if you look at the drawings of some of them on the next page as they are seen under the microscope, magnified thousands of times their natural size; but there are others of different shapes. On the same page too there is a handsome shell, called an ammonite, and of its real size, common in chalk rocks. The seas of the time must have been very deep as I have explained before, and the chalk contains numbers of bones of fishes everywhere, and many of the remains of the reptile-like creatures of the time before. Corals, sea-urchins, crabs, &c., abounded, and as you can scarcely ever see chalk without immense flint stones in it, you may suppose what millions of sponges lived on the rocks, for these flints are partly made up of their fossil bodies.[14] Another Cretaceous period is beginning now at the bottom of the Atlantic and Pacific Oceans, where it is deep enough to cover the Alps, for these little foraminifera are living on the surface in countless millions, and day by day their fossil shells are settling down to the bottom and forming a soft grey mud, full of the carbonate of lime like chalk. The climate of the Cretaceous age was mild and pleasant, as we know from the kind of animals in the seas. Slowly the water began to get shallower and shallower by the upheaval of the bed, and at last the bottom of this mighty chalk ocean came up to the light and sun, to be covered in some places with the drift and worn particles of older rocks swept over it by rivers, and to receive new plants and new animals, and in some places to remain almost bare, as it is on the downs of Brighton.

FOSSILS OF THE CHALK.

1 _Ammonite._
2 3 4 _Foraminifera_ (_Chalk-builders_).]

Now we take one more step upwards into almost a new world—the world on which mighty animals lived, and which man came to share with them.

THE TERTIARY PERIOD.

The reign of the reptiles is now passed. The ichthyosaurus and pterodactyl no longer inhabited the seas and continents. Great changes had taken place in the shape of the land. A river larger than the Rhine swept majestically through England from the borders of Wales right out into the German Ocean, and its banks were covered with forests and marshes, where the new animals which had come to take possession of the earth lived and moved and had their being. The mountains of the Pyrenees were raised above the sea, and parts of Surrey and Sussex appeared too. It was most likely in the early part of the Tertiary period that the stone was formed of which almost all Paris is built. Fancy a great city built of the shells of dead animals! One can scarcely believe it: but the microscope lets us into this secret of Nature. If we take a piece of this stone and examine it in a powerful microscope we see that it is made almost entirely of tiny shells, so small that myriads of them could be packed in a nut-shell. How long must they have been working to make all the stone beds of which Paris is built? We cannot measure the time, we can only know it must have been enormous!

All kinds of animals both of sea and land increased in numbers and perfection. The ammonites were dead, but their even more beautiful relation, the nautilus, was living as it is now. The trilobite was gone, but his next relation, the lobster and crab, appeared. Fishes abounded. Whales which suckle their young ones appeared, and the numbers of vertebrata, or animals with backbones, were more numerous than they had ever been before. Just as animals with bones are more perfect than those with only skins or shells, so animals which suckle their young ones are more perfect than those which only lay eggs. Thus the whale is a more perfect animal than the shark, though both inhabit the water; and elephants and even rats and mice more perfect still; and because there were so many of these “sucklers,” or mammalia as they are called, in the Tertiary period, we know that all living creatures were becoming more perfect. It will interest you too to learn that monkeys began to appear now, and that they were common in France, while at the present time the only part of Europe where they are to be found is on the rock of Gibraltar.

But I want particularly to tell you of the giant animals—the Mammoth, Mastodon, Megatherium, Dinotherium, and others, and first let us see what the mammoth was like.

In former times, when people accidentally found the bones of these animals, they actually thought they had belonged to giant _men_, and we can scarcely wonder at that: but we know better. If only one small bone is shown to Professor Owen or Professor Huxley, he can tell at once whether it belonged to a man or an animal, a fish or a bird, and very often the particular animal too. Well, the bones of the mammoth were found in the north of Russia on the banks of the river Lena in 1800: but the Russians knew of them before that, and the name they gave the animal means “earth,” because they supposed it burrowed in the earth like a mole. This one is now in the Museum at St. Petersburg, and its brownish coat and long black hairs, and even the hoofs and some of the flesh, can be distinctly seen. The drawing in the frontispiece is taken from it. It was strange that any people could have supposed that this huge creature, larger than an elephant and with great curved tusks ten feet long and weighing 160 lbs., could have got underground of its own accord: but that was the only way in which they could account for finding it buried in the earth on the banks of the rivers. Look at the picture in the frontispiece; what a splendid animal he was, this old elephant; larger and stronger than any living elephants! Immense quantities of their bones are found in Siberia, and the tusks and teeth are brought in ship-loads to England, where they are sold for their ivory. Their skeletons have been found in most countries of Europe, in many parts of Asia, and in North America, and these animals must have been common at one time near London, for their bones have been dug up in the brick earth at Ilford in Essex and other places near the Thames. There is a skull with tusks set up with iron supports in the British Museum.[15]

There was besides another animal very much like this called the Mastodon; but it had tusks in the lower jaws as well as the upper, four in all, and the lower tusks dropped out when the animal grew old. The whole skeleton of one of these is also put up in the Museum, which you ought to go and see.[16] Mastodons’ bones have been discovered in England and other parts of Europe, and in North and South America and India, so that they were spread pretty well all over the world. They had very curious pointed teeth rather like a lot of fir cones piled together, not flat grinders like those of the mammoth and all living elephants, and perhaps they fed upon fruits and nuts, and boughs, as I do not think they could have managed well to chew grass and leaves with such pointed teeth. The teeth in their old dead jaws are still beautifully white and look like china. Both the mammoth and the mastodon had long trunks of course, and they must have been grand looking creatures marching about in the English forests. We should be very much startled if we were to meet one of them now in an English wood: but there is no chance of that, they have all passed away, and the only relations they have living are the elephants of Africa and Asia.

During this Tertiary period, or at least the early part of it, besides the mammoth and mastodon, the hippopotamus and rhinoceros were plentiful about the Thames. Those same Ilford marshes in Essex have been a complete storehouse of the remains of these animals. The bones of a hundred different mammoths and eighty rhinoceroses have been dug up lately from the damp, black soil, as well as many belonging to the hippopotamus, and we can have no doubt that all the swamps along the north side of the river were inhabited by large herds of these huge beasts, or so many of their skeletons could not have been collected in one place. It is very likely they were overtaken in a flood of the river and drowned, and their bodies sank down in the mud of the river bank: but anyhow, there they are to tell us that they lived and died almost within sight of the Tower of London, if it had been built then, as of course it was not.

_Gigantic Irish Stag_ (_Cervus Megaceros_).]