Having now taken leave of the curious pouch-bearers and the strange primitive sloths and armadilloes, we find ourselves left to deal with an immense multitude of modern mammalia, which have spread in endless variety over the earth, and which may be divided into five great groups—the Insectivora or insect-eaters; the Rodents or gnawers; the climbing and fruit-eating Lemurs and Monkeys; the Herbivora or large vegetable-feeding animals; and the Carnivora or flesh-eaters.

All these groups are very distinct now, and we naturally turn back to ancient times to ask how they first started each upon their own road. But when we do this, we meet with a history so strange that it makes us long to open the great book of Nature still further, and by ransacking the crust of the earth in all countries to try and find the explanation, which will no doubt come some day to patient explorers. The history is this. We saw in the last chapter that in those far distant ages, when even reptiles were only beginning to spread and multiply by land and sea, and when, although birds probably existed, still they did not as yet leave any traces behind, small milk-giving and insect-eating animals, the Microlestes and Dromatherium (see p. 183), were already living upon the earth, and left their teeth and jaws in the ground.

Now, as ages passed on and the reptiles increased in strength, these little milk-giving animals evidently flourished, for though we have not yet discovered any of their bones in the rocks of the Chalk Period, yet as we find them both before and after that time, they must have lived on in some part of the world, the rich vegetation and abundant insect life affording them plenty of food. Meanwhile the huge reptiles, of kinds now long extinct, reigned over land and sea and air, and were in the height of their glory,—when suddenly there comes a blank and their history ends. When we look again, “a change has come o’er the spirit of the dream,” and in the next period we find their bones no more. From that time we meet only with the four groups of lizards, snakes, tortoises, and crocodiles, which still survive; and the place of the swimming, flying, and walking reptiles is taken by four-footed and milk-giving animals.

Some of these were still marsupials like those that had gone before; others were of strange forms, distantly related to them; others were curious ancestral forms of our hyænas and bears, dogs and civets, horses and tapirs,129 in which the characters which distinguish these groups were not so distinct as they are now, while others again were old forms of moles, hedgehogs, squirrels, bats, and lemurs. In what part of the world, then, had all these been growing up, that we come upon them so suddenly? Before the seas of the chalk only the small marsupials; after them, when the areas of land began to increase in extent, a whole army of milk-givers, so different from each other and so well adapted for their lives, that we even find among them such peculiar forms as whales, with their arms converted into paddles, and bats with their arms acting as wings.

What an idea this gives us of the immense period of time that must have elapsed while the chalk was forming, the reptiles becoming extinct, and the mammalia taking their place!

We have had a hint of this before, when we learned in Life and her Children how infinitely minute the shells are of which chalk is made, and what enormous thicknesses remain of the chalk-beds. And now we find these facts strengthened by the great changes which then took place in the animal world, for even if (as is likely) older forms of these large milk-givers existed in earlier times, and we have not yet found them, yet there are such great differences between whales, bats, dogs, and lemurs, that our imagination stands appalled at the time required to account for them.

Again, where are the traces of all the forms which must have existed between the little marsupials and this great army of four-footed beasts? At present no one can answer. Forty years ago we knew nothing even of those early marsupials, and people said there were no milk-giving animals until after the time when the chalk was formed. Now a few jaws have told us that milk-givers had been already in the world for ages; and it may be that before forty years more have passed, some child now reading these lines, and following in the footsteps of such patient explorers as Beckles and Gaudry, or the American naturalists Leidy, Cope, Marsh and others, who have such a grand field before them, may discover bones which will unravel the history of that crowd of mammalia which now seems to start up like Cadmus’ army from the ground.

But for the present we can only begin with them as we find them immediately after the Chalk Period, and a strange motley group they appear. There, roaming among the palms, evergreens, screw-pines and tree-ferns, which flourished in Europe and North America in those warmer times, were beasts larger than oxen, with teeth partly like the tapir, partly like the bear, and feet like the elephant,130 which may have been both animal and vegetable feeders. With them were true vegetarians, which could be called neither rhinoceroses, horses, nor tapirs, but had some likeness to each.131 Others, half-pigs half-antelopes, were thick-skinned, but graceful and two-toed,132 while a little fellow no bigger than a fox,133 with five toes on his front feet and three behind, the ancestor of our horses, grazed in the open plains. There too, moles, hedgehogs, and dormice had already begun to make their underground homes, and squirrels and lemurs sprang about the trees of the forest, where bats roamed at night in search of insects. Nor was this life without its dangers, for beasts of prey, half-bears half-hyænas,134 were there to feed upon their neighbours, and with them a creature half-dog half-civet,135 with several other carnivorous animals with feeble brains and partly marsupial characters,136 and lastly a large flat-footed dog-bear,137 something between a dog, a cat, and a bear, with a very small brain but plenty of teeth, represented the most primitive flesh-eating animal known to us.

None of these forms were of the same species as those now living, and many of them, as we see, had characters which we now find in two or three different animals; showing that they had not yet specialised the various weapons of attack and defence, and the difference of limbs and teeth which now distinguish their descendants. So that, for example, though there were fierce animals of prey, none had yet the formidable teeth of the tiger nor the muscular strength of the lion, neither had the vegetarians the fleetness of the horse, the horns of the deer, nor the large brain of the elephant.

This had all to come with time, and from that day to this their descendants have been spreading over the earth. Some, large and powerful, have conquered by strength; some, by superior intelligence, have learned to herd together and protect each other in the battle of life; some have gone back to the water and imitated the fish in their ocean home; and others, smaller and feebler, have lived on by means of their insignificance, their rapid multiplication, and their power of hiding, and feeding on prey too minute to attract their more powerful neighbours.

Among all these there are hundreds of different forms, branching out here and there, crossing each other’s path and often jostling on the way; while during the long period between our first knowledge of them and now, they have been driven or have travelled from one country to another, from the northern to the southern hemisphere, or from the Old to the New World, till in many cases it is impossible to say what routes they have taken.

How, then, shall we get a glimpse of the nature of these large groups? Shall we take the moles and hedgehogs as the lowest, and the monkeys as the highest, and then travel in a straight line through the forms between? Scarcely, I think, for it is very doubtful whether the lemur and the dormouse may not be able to boast of ancestors as ancient as the moles, while the elephant and the dog are surely as intelligent and far nobler animals than the monkey. No! we must make up our minds at once that the different branches have grown side by side to much the same height, so that our genealogical tree, if it were possible to make one, would, like a real tree, be a mass of entangled twigs, some of which would, indeed, be less aspiring than others, yet on the whole we could scarcely say that one reached nearer to the sky than another. What perfection they have each obtained in their own line is quite another question, and one which we are able to trace out.

Thus, for example, the gnawing animals or Rodents, and the insect-eaters or Insectivores, are undoubtedly the lowest types next to the sloths and armadilloes, the insect-eaters especially having very primitive skeletons and small brains. Yet we shall find that we pass very naturally from them to the intelligent monkeys, while, on the other hand, the vegetable-feeders and flesh-eaters go off upon quite a different line of their own.

Let us, then, begin with these two lowly groups, the Rodents and Insectivores, and see how they have conquered their humble place in the world. One thing is clear, that they do not hold it by strength or audacity, for taken as a whole they are small and weak animals; the giants among rodents, the Capybaras of South America, where all lower kinds of animals thrive, are only as large as good-sized pigs, and the smallest, the “Pocket-mice” of North America, are not bigger than large locusts; while the insect-eaters have nothing larger than the “Tenrecs” or soft-bristled hedgehogs of Madagascar, about the size of a tailless cat; and the rest of the group vary from two to eight inches all over the world. Moreover, they are as a rule timid, and though some of them fight fiercely among themselves, yet they scamper away and hide at the least alarm, and generally choose the twilight or the dark night for their feeding time.

Stroll out some fine summer’s evening, when the sun has set and the moon has not yet risen, and as you wander in the fields and woods with eye and ear open, you will scarcely have gone far before you will be aware that there is plenty of stir going on. Some active little field-mouse will cross your path in her eager search for grain and seeds to lay up for her winter store, or you may startle a hare in the long grass and watch her run across the field, or see her sit upright on her haunches surveying the quiet night-world. Or, if you pass over a common, the number of little white tips glancing in the twilight from under the furze bushes will tell you that the rabbits have not yet disappeared into their burrows; while as you enter the wood the sharp little eyes of the squirrel will peep down upon you from the beech trees, as she watches over her little ones in their comfortable nest in the branches.

All these are Rodents, and you may know them by their four long chisel-like front teeth (see B, Fig. 55), which have a large gap on each side, between them and the grinding teeth behind. These chisel teeth have not bony roots like the teeth of most animals, but rest in a deep socket, and continue growing during the whole of the animal’s life; and they have a hard coat of enamel in front, so that as the tooth wears away behind, this enamel stands out and forms a sharp cutting edge, and there is perhaps no tool more efficient for gnawing a root, a nutshell, or the solid wood of a tree, than the tooth of a beaver or rat.

But these animals have another and quite a different set of companions, as you will learn if you are lucky enough, by looking carefully along the hedge, to startle a little shrew in its quest for worms, or to catch a hedgehog shuffling along at a sharp trot after his nightly meal of beetles, slugs, and snails; nay, you may even, if it be early summer, come across a mole, or find two fighting fiercely together for possession of the only thing they come to the upper world to fetch—a wife.

These creatures have not the long front chisels of the hare or the shrew; on the contrary, their mouth is small, and crowded with a number of fine pointed teeth (see A, Fig. 55), of which even the back ones have sharp cusps or points, well fitted for crushing insects. For these are Insectivora or insect-eaters; and while the rodents are gnawing at roots and leaves and nuts, these devourers of small fry mingle with them very amicably; while both groups only ask that the night-owl may not see them in their evening wanderings, nor the weasel and his bloodthirsty tribe attack them in their homes.

For, ever since they began the race of life, long long ago, these two very different orders of animals have been trying to feed without risk, and to keep out of the way of flesh-eating birds and larger creatures. And so it has come to pass that, though the rodents are mostly plant-eaters, while their associates are insect-eaters, yet, as both are trying to conceal themselves, and get their food by stealth, they have acquired curiously similar external forms, weapons, and habits of life, with the one exception of their teeth and the manner of eating their food.

Even in our English meadows a casual observer might easily mistake the little insect-eating shrew, with its soft velvety coat and bare paws (Fig. 56), for a near relation of the gnawing Harvest-mouse nibbling the grass tips just above its head (Fig. 57); though a nearer inspection of the shrew’s long snout, small ears, and sharp teeth, would show the difference. And as to their way of life, the Field-shrew and the larger Field-mouse live like two brothers of the same race. They both make burrows in the banks, though the field-mouse digs the deeper hole, and they both line their home with dry grass to bring up their little ones. And when the winter comes they both retreat into their homes; the shrew to sleep away the dark days, and the mouse to wake from time to time to feed upon his store. Only their food is quite different, and when they come out in the twilight of the summer’s evening, the mouse is on the look out for acorns, nuts, grains, and roots, which it gnaws off with its sharp chisels, while the shrew is chasing worms and insects, or cracking tiny snails with its pointed teeth.

Then if you lie and watch quietly by the bank of a river, there you may see the Water-rat or Vole (not the land-rat which sometimes hunts for prey in the water) diving under with a splash to gnaw the roots of the duckweed or the stems of the green flags, and coming up to sit on the bank, and hold them in his paws as he eats them; while not far off a pretty little Water-shrew, this time too small and different to be mistaken for his companion, is swimming along with his hind feet, the air bubbles covering his velvety back with silvery lustre as he chases water-shrimps, or feeds on fish-spawn or young frogs. Both these animals live in streams and rivers, and bring up their young in holes in the bank, where they can jump into the water if the weasel attacks them, or the common snake pokes his head too near their home.

These are perhaps the chief examples we shall find in England of insect-eaters and gnawers living near together and following the same kind of life; but if we look over the world it is most curious how many parallels we can draw between them, showing how the same dangers have led to the same defences.

Look among the insect-eaters at our Hedgehog (Fig. 56), so weak and shuffling in his movements that he would have been cleared out of the world long ago but for the sharp elastic spines which grow upon his back in the place of hair. There he goes trotting along under the hedges in the twilight, cracking the horny skins of beetles, or sucking eggs, or devouring worms, slugs and mice when he can get them, without a thought of fear. For he can roll himself up in an instant if danger be near, and his sharp spines will keep off even dogs and foxes, unless they can catch him unawares, and bite him underneath in his soft throat. Nay, he can actually master a poisonous snake, and use it for food, not suffering even from the adder’s fangs when they pierce his tender nose.

It is curious to see how quickly he can roll himself up by drawing together the strong band of muscle which passes along the sides of his body from head to tail, sending out bands of muscle to feet, head, and legs. When he contracts this band his limbs are all drawn in, and the spiny back forms a kind of prickly bag all round them, even his tender snout being safely hidden. Nor are his spines merely sharp—they are as elastic as the hair of which they are modifications; and the hedgehog can drop safely from a height when he is in his ball-shape, falling on the spines, which bend and straighten again as though made of whalebone. So he lives under hedges and in ditches till the winter comes, when he settles down in a nest of moss and leaves in a hedgebank or a hollow tree, and sleeps the cold weather away. And when the spring comes he takes a wife, who brings up her little ones in the nest of moss and leaves under the hedgerow, watching over them as long as their spines are soft.

And now where shall we look among the rodents for a creature to match the hedgehog among insect-eaters? Surely to the “fretful Porcupines,” which feed on all kinds of vegetable food in Southern Europe, Africa, Asia, and America, protecting themselves by the formidable array of spines which they can raise at will. Even the European porcupine, which is about two feet long and the weakest of his tribe, is better protected than is generally believed. It is true that his long black and white ringed spines only cover the hinder part of his body, but the hair of his head and neck hides a number of short spines which can give very sharp pricks; and though he is a timid night-loving animal, hiding by day in burrows and holes of the rocks, yet when attacked he jerks himself up against his enemy, so that the long spines wound very severely. And when we come to the Tree-porcupines, which hang by their tails from the palm trees in Mexico and Brazil, we find that their short stout spines are a very efficient defence both against birds of prey and the deadly coils of the boa constrictor and other large snakes; while the Western porcupine and the almost tailless Canada porcupine, which climb trees and strip off their bark and buds, have a clothing of such dangerous weapons that pumas and wolves have been known to die of inflammation from the wounds.

The porcupine among the rodents, then, like the hedgehog among insect-eaters, has adopted prickles as a defence. But there are many soft-haired creatures living upon the ground in both families which have no protection but concealment, and we find them both gaining it by burrowing into the ground. Among the insect-eaters the Mole is the most successful digger, and as he works his tortuous way through the ground in search of worms and grubs, it is scarcely possible to imagine a miner more usefully equipped for his work. His skeleton, it is true, is, on the whole, more primitive and roughly finished than that of higher animals, his ear is almost closed, and his eye though bright is deeply hidden; but the parts specially necessary to him are most wonderfully fitted for the work they have to do.

His broad shovel-like front paws (see Fig. 56), with their five strong claws, set each in a long groove at the tip of the last finger-joint, are powerful tools for shovelling away the earth, as he turns them outwards and pushes with them as if he were swimming; and they are carried on strong, short, and broad front legs, fixed to collar-bones and a shoulder blade of unusual strength, while the breastbone is so formed as to throw the legs forward and bring them on a level with his nose when he is burrowing. This nose, too, has its part to play, for it is long and slender, with a small bone at the tip, which helps him in pushing his way forwards while his hind feet are planted flat and firm on the ground behind, while it also serves to pick out the grubs, worms, and beetles from their narrow holes.

Here, then, we have the very best of miners, who has secured food and safety far from the busy world above, and spends his time hunting for grubs and earth-worms in the dark earth below. He is a most voracious animal, and makes the ground above him heave and swell as he toils through it eager for prey, pushing up every now and then with his nose the loose earth he has excavated, thus marking the line of his route by molehills.

But when he builds his home and fortress where he takes his long winter’s sleep, and hides from weasels and pole-cats, he takes care to throw no loose rubbish above; on the contrary, he presses the earth together so as to make the walls of his chamber firm and hard, and carries out from it a number of passages, by any of which he can reach his home in safety when he is pursued too closely.

Thus by his cleverness in burrowing, and the useful tools which he carries upon his body, the mole has managed to find safe feeding-ground and shelter, when no doubt many of his relations living above ground have been killed off. Even underground he has his enemies, for the Weasel, the Stoat, and the Badger find him good eating, while if he meets one of his own brothers in a narrow passage they will fight till one is killed and eaten; yet though fierce he is also tender-hearted, for mole-catchers say that when a mother-mole is caught in a trap the father may sometimes be found dead by her side.

And now if we turn to the rodents for rivals to the mole, we are almost confounded by the multitude of creatures which have found safety in burrowing. Not only have we the rabbit-warrens, by which the sandy soil of our commons is riddled in every direction with holes, leading to burrows where the mother lies snugly hidden with her five or six naked little ones in a bed of her own fur; but we have the extensive burrows of the little, long-legged, leaping, gnawing Jerboas of Africa, which are so like the Jumping Shrews among insect-eaters. Then again there are the underground cities of the South American Viscachas and Chinchillas, and the extensive subterranean settlements of the Lemmings,—those curious rodents, which from time to time start off in vast swarms across Norway, over mountain and valley, through flood and fen, over rivers and plains, preyed upon by eagles and hawks, foxes and weasels, on their way, but never stopping or swerving in their course till they reach the sea, into which they plunge and drown themselves. Again, every inhabitant of Switzerland knows the Marmot and the burrows he forms, scratching up the earth with his hind feet and patting it together with his front paws and his broad nose; while every American child has heard of the hillocks thrown up by the “Prairie Dogs,”138 which undermine whole plains in the far west with their underground cities, where the burrowing owl shares their home with them, and the rattlesnake steals their young.

But all these come out upon the land and use their burrows chiefly for homes and nurseries. We can match the mole better than this among rodents, for in Eastern Europe, India, and Africa, there are blind creatures called Mole-rats139 (see Fig. 57), with broad flat heads, small eyes hidden in their fur, short tails, and feet with sharp claws, which live almost entirely underground, burrowing subterranean galleries in the sandy plains in search of roots, as the mole does for worms; while the Pouched Rats140 of North America also live in burrows, throwing up hills just like mole-hills, and gnawing roots and buried seeds, which they carry in their large cheek-pouches, to store up in their underground chamber for winter food.

Nevertheless, the rodents can scarcely compete with the mole as burrowers, and it is not till we come to the water-animals that they begin to have the best of it. True, the insect-eaters have the Water-shrew and the curious West African Shrew,143 with its broad tail; while the Desman144 of Russia and the Pyrenees (see Fig. 58), with his dense furry coat, his broad tail, and his webbed feet, is quite a match for the gnawing Musk-rat or Musquash of North America, for they both live in fortresses on the river-banks, to which hidden passages are well contrived to elude pursuit; and while the desman, with his curious movable snout, pokes about in the Russian or Pyrenean streams after leeches, water-snails and insects, the musquash in America gnaws off the roots and stems of water-plants.

But the insect-eaters have no water-animal to match the Beaver in sagacity, judgment, or engineering. For here we have a creature not much larger than a good-sized cat, cutting down trees, dragging logs six feet long to the water’s edge, and building with them the most elaborate log-houses and water-dams. With hind feet webbed up to the claws, and his broad tail as a rudder, the beaver has so much swimming power that his fore legs are free to carry and place the wood, while his broad orange-coloured teeth, as sharp as chisels, which grow as fast as he wears them away, are his cutting instruments. With them he gnaws a deep notch in the trunk of a larch or pine or willow, as deep as he dares without fear of its falling, and then going round to the other side, begins work there till the trunk is severed and falls heavily on the side of the deep notch, and therefore away from himself. Then, after stripping off the bark and gnawing the trunk into pieces about six feet long, he uses his fore-paws and his teeth to drag them into position to build his dam. The lighter branches he uses to make his oven-shaped lodge, laying them down in basket-work shape, plastering them with mud, grass, and moss, and lining the chambers with wood-fibre, and dry grass; and the logs he piles up to form dams, lest at any time the stream should flow away and leave the entrances to his home dry. These dams are very skilfully and cunningly formed. He always makes the deep notch in the trunk on the side near the water, so that the tree in falling comes as near as possible to the stream; then he does not always clear away all the branches, but he and his companions place the logs with these lying down the stream, so that they act as supports to resist the current and prevent the dam being washed away. Thus they make a broad foundation, sometimes as much as six feet wide, and upon this they pile logs and stones and mud till they have made a barrier often ten feet high and more than a hundred feet long.

In this way they clear the woods just round their stream, as if a whole gang of wood-cutters had been there at work; and as the dams check back the water and form broad meres, there are soon swamps on all sides, where peat moss grows and “beaver-meadows” are formed.

Here the beavers live in companies, each in his own chamber with his wife and family, though underground passages often lead from one to the other, and when water-plants and soft bark are scarce, they will often travel some way inland to feed on fruits and grain. But if among the community any are lazy or will not take partners, they are driven out, to find a refuge in holes of the river-banks, where they sulk alone.

In Western Europe, indeed, where they have been so much persecuted, most of the beavers live alone in holes, though communities are still left in parts of Germany, Scandinavia, and Siberia. But in North America they still carry on their true communal life, and those who visit their wonderful settlements will not be surprised to learn that they possess the largest brain for their size of any of the gnawing animals.

Indeed, they would have no rival among rodents if it were not for the clever sagacious rats, and these have probably sharpened their wits by living so long in contact with man, for they are burrowers chiefly in human dwellings, granaries, stables, mines, ships, and every available dwelling-place where they can rob and plunder, and outwit even man himself by working their way into his stores, and acting together in carrying away his goods.

So the insect-eaters and rodents hold their own both by land and water, penetrating, in the forms of bats and mice even to Australia, though the rodents are most widely spread, for except two very rare animals145 in the West Indian Islands, there are no Insectivora except bats in South America. The bats, however, remind us that both these groups have also found homes above the ground and in the trees. There the rodents have the lovely little Squirrels, which, with their brown red backs, white waistcoats, and graceful bushy tails, scamper up the trees of our English woods. It is very tempting to dwell upon the squirrel, with his little wife, to whom he remains faithful all his life, his beautiful round nest, in which his young are so carefully reared, and his pretty ways as he sits upright gnawing beechnuts or acorns, holding them in his tiny hands. He has made good use of his opportunities, being almost as widely spread as the rat, for there are squirrels of some kind all over the world, wherever there are forests, except in Australia. Several of them in the East and North America have folds of skin at the side of the body, which, when tightly stretched, by extending the four limbs, enable them to take flying leaps from tree to tree (see Fig. 60). Even without flying, however, the squirrel is so nimble that he manages well to escape his enemies, except some of the birds of prey and the fierce tree-marten and wild cat; and as in cold countries he sleeps soundly in snug holes of a tree till the leaves grow again to give him shelter, he is not often detected even by these.

Nevertheless, in tree-life and in the air it is the turn of the insect-eaters to claim the advantage. It is true that the insect-eating Bangsrings,148 which scamper up the trees in Sumatra and South-East Asia, and were long mistaken for squirrels, are a small family and not of much importance; but what shall we say to the Bats, the only true flying milk-givers? Or what, again, to that curious animal the Colugo or Flying Lemur of the Malay Islands, which belongs to the insect-eaters, and yet has some points like marsupials, some like fruit-bats, and some like the true lemurs? This strange creature, which seems like the remnant of some branch-line from very ancient times, climbs the tree like a squirrel by means of its claws, and then spreading out its limbs displays a broad membrane (see Fig. 60) stretching not only along its sides but across its tail, and from the front of the arms to the neck as in bats, and so sails down from one tree to another. The mother, which Mr. Wallace examined, nurses the little one on her breast just as the lemurs do, while large folds of her skin protects the small, bald, naked little creature, something after the manner of an imperfect pouch. Lastly, while they sometimes feed on insects, the chief diet of these colugos is fruit, like the lemurs, to which group they were once supposed to belong.

But of all modified insect-eaters the most extraordinary are the Bats, which are so different from all the others that they have been placed in a distinct order149 of their own. Imagine a little creature about three inches long, with a body something like a shrew, large ears, a protruding snout, and plenty of sharp teeth (see Figs. 61 and 62). Let it have a breast bone projecting more than in most milk-givers, and covered with a large mass of muscle as in birds, fitted to move the wings, but having nipples to suckle its young. Let it have large shoulder-blades and collar-bones, a strong upper arm, a very long lower arm (fa, Fig. 61), and four immensely long fingers to its hand (ha), and a short clawed thumb (t). Let its hind legs be short and weak, with a long spur behind the heel (h) of its five-toed feet, and finally let the skin of its body grow on over the arms and long fingers, filling in the space between the elbows and the neck in front, and stretching away behind, over the legs down to the ankle, and on behind the legs, so as to enclose the tail. This skin growing from the back above, and the under part of the body below, will enclose the bones of the arms, hands, and legs, like a kite with calico stretched on both sides (see Fig. 56, p. 220), and when the long fingers are outspread and the legs opened, no limbs will be seen, but only a small body and head, with an immense expanse of skinny wing, from which the short clawed thumbs and the four toes of the feet stick out before and behind.

Now this creature is no longer like the flying squirrels or the colugo, which can only take floating leaps; for though like them it has only a membrane stretching out from its body, yet this has become a long flexible wing, formed on a widely outstretched arm and abnormally long hand, and moved by powerful muscles like the wings of birds or insects. It is essentially fitted for flitting through the air in search of prey, while it makes but little use of the running power which it possesses in common with all other insect-eaters. If you see a bat moving along the ground, you will acknowledge at once that it is a true quadruped, yet, by its awkward gait as it shuffles along on its clawed thumb and toes, you will judge that it is not an earth-loving animal. Watch it at night on the wing and it is quite another creature; then it will flit about in and out of cracks and crevices, under the eaves, round the haystacks, or among the trees, and never once strike its wings against anything, though it has been proved that it does not trust chiefly to its bead-like eyes to guide it.

Bats have been blinded, their ears stopped with wool, and their noses with sponge dipped in camphor; and yet, without sight, hearing, or smell, they steered quite successfully between outstretched threads or tree-branches, or found their way into a hole in the roof. In truth, as they have become fitted to navigate the air, they seem also to have become sensitive to its currents. Their wings are abundantly supplied with nerves and blood-vessels, and have little rough points all over the surface; their ears have generally a second ear-lobe or leaf within the outer one, and those which have not this have leaves of skin or membrane round their nose. With all these they seem to feel the slightest difference in the air, so as to detect at once whether they are in the open, or whether any resisting object is near them.

Now it is clear that a creature of this kind, able to chase insects in the air, even in the darkest night, can secure much food that the running insect-eaters can never reach. When the little common English bat, the Pipistrelle, awakes from his day’s sleep, which he has been taking, head downwards, hanging by his feet in some old tree or under the roof of a barn, he finds the gnats and flies abroad, and begins his chase in the twilight—up and down, from side to side he flits, and his wide-open mouth takes in insects at every turn. And by-and-by, as the dark nights come on, the Long-eared Bats begin gradually to stir from their clusters in the barns and old buildings, and, unfolding their wings so as to display their ears as long as their bodies, commit sad havoc among the night-moths. All night long their shrill squeak may be heard, but before day dawns they are away again, and may be found hanging in dense masses by their hind legs to the timbers of some old church belfry, or in caves, or even under the roofs of houses, where they find an entrance by some hole, and go in by hundreds to hang from the rafters.

Many accounts are given in American writers of the thousands of bats collected in the caverns which abound in the Western States, while in the Egyptian catacombs they hang in myriads. For of all things a bat dreads the light when beasts of prey are abroad, and next to that he fears any position near the ground where weasels, wild cats, or other flesh-eating animals may seize him in his sleep. Nay, the smaller bats live in constant fear of the larger ones, for they feed upon one another with evident relish.

Yet in spite of dangers the bat family, aided by its power of flight, has spread all over the world, from the Arctic Circle to the Equator, east, west, north, and south. In cold countries they hang by their feet in the winter, or sometimes by their clawed thumbs, and sleep in dark recesses, scarcely breathing till the warm weather and the insects return; but in warm countries they are active all the year, sleeping by day and feeding by night.

In England and North America they are content chiefly with insect food, but in South America the Vampires, among the leaf-nosed bats, fasten on to large animals and suck their blood. Mr. Darwin had his servant’s horse bitten and disabled for two days by a vampire in Chili; while Mr. Wallace, when on the Amazon River, was himself twice bitten, once upon the great toe, and once on the tip of his nose while asleep! A bat is a grotesque-looking animal at best; but some of these leaf-nosed bats are simply hideous, with their wide-open mouth, sharp teeth, and the skinny leaves sticking up round their nose.

How different are the gentle-looking fruit-eating bats of the Tropics, which seem to belong to quite a different branch of the family. Their fox-like and intelligent faces are a pleasure to look at, reminding one of the lemurs, and harmonising beautifully with their quiet peaceful life among the fig-trees, guavas, mango-trees, and plantains of the East. There they hang in dense masses from the tall silk-cotton trees till night comes on, and then take wing as soon as the sun is set, and hooking themselves by one thumb to the fruit-trees, hold the fruit in the other as they feed.

Thus we have a wide range of habits in bats, from the insect-eaters to the blood-sucking vampires on one hand, and the gentle fruit-bats on the other.

But one virtue the most bloodthirsty and the most gentle have in common, and that is maternal love. As soon as the little ones are born they cling to their mother’s breast, and she often folds over them the skin which covers her tail, so as to form a kind of pouch, so that wherever she flies they go with her, and are carefully tended and suckled by her till they can take up the chase for themselves.

And now we have followed out the Rodents and Insectivora in their various lines. Both lowly groups, of simple structure and with comparatively feeble brains, they have chiefly escaped destruction from higher forms by means of their nocturnal and burrowing habits or arboreal lives, and the marvellous rapidity with which they breed, combined with their power of sleeping without food during the winter in all cold countries. Nevertheless, though they are often strangely alike in outward form, they differ in many remarkable respects. The insect-eaters now existing are chiefly a few straggling forms of a once widely-spread group; while the rodents, on the contrary, are still a very numerous and varied family, spread all over the earth, and boasting of such intelligent forms as the squirrel, the beaver, and the rat. But here their advantages appear to end, while the insectivora point onwards not only to the bats, the only flying milk-givers, but also through the colugo to the lemurs, and thus onwards to the monkeys. It may be, and indeed probably is true, that the colugo started off from some very early type, more nearly related to the pouch-bearers than the present insect-eaters are; while the monkeys, again, branched off long ago on another line quite separate from the modern lemurs. But if the tiny shrew wished, like many little people, to boast of distinguished connections, he might with justice suggest that somewhere among his primitive ancestors one would probably be found whose descendants had risen far higher in the world than himself.