Yet the whales and dolphins, at any rate, have not only adopted a sea life, but have limbs so like a fish's fins that we can scarcely call them by any other name, and they are so completely water animals that they cannot even return to the land.

Now we should be quite puzzled to account for such curious forms as these warm-blooded animals, half transformed into fish, if it were not that we know of several land animals belonging to different groups which have gone part of the way towards a fish life. Thus among the reptiles we have the oceanic turtles and the sea snakes; among birds the penguins, whose wings have almost become fins. Then among the milk-givers we have the web-footed Duck-billed Platypus, the Yapock or web-footed opossum of South America, the Desman and the Beaver, the Polar Bear, and last but not least the Otters, web-footed animals nearly allied to the weasels, which seek their food entirely in the water.

The common Otter of Europe and America, though he moves quickly and actively on land, has webbed toes with only short claws standing out beyond the swimming foot, and he spends the greater part of his life in the river, making his home in a hollow of the bank beneath the overhanging roots of trees. There he may still be seen in many of our English rivers, his soft brown fur shining as he swims along, diving under water for a fish, which he brings out on to the bank to eat, holding it in his fore paws.

But there is an otter which has deserted the old land life much more completely than this, for the great Sea-Otters of the North Pacific, about four or five feet long (see Fig. 79), never care even to come on shore, but, when they have dived for their prey, turn on their backs and float while they eat it, holding the sea-urchins, crabs, or fish, in their front paws. They, even nurse their young ones in the same fashion, dandling them in their arms as they lie face upwards on the sea; and they rear them entirely on the thick beds of kelp off the coasts of the North Pacific Ocean, never bringing them on land.

These sea-otters may be seen in hundreds off the coasts of Alaska and California, basking on the wet rocks, playing, leaping, and plunging in the water, till some alarm makes each mother seize her little one in her teeth and dive under in an instant.

They are twice the size of the River Otter, and in many points more like seals, for though their front paws arc short and cat-like, their hind feet are flat flippers, with a long outer toe; their face too is broad and short, and their teeth are neither cutting like the weasels nor flattened like the bears, but covered with rounded knobs, well fitted for crushing crab-shells and the bones of the fish on which they feed.

We see, then, that it is quite possible for l and animals to have near relations specially adapted for a sea life. But the otter is still distinctly a four-footed creature, with free arms and legs, and we can trace his connection with the weasel tribe. It is quite different with the three groups of real fin-footed animals—the Seals and Walruses, the Manatees, and the Whales. Though we can trace their likeness bone by bone to the land animals, yet they have become so different as to show that they must have branched off long long ago o so long indeed that we cannot even guess at the relations of the whales, while the seals have only a distant resemblance to the bear family, and the seacows or manatees to the ancestors of the hoofed animals and elephants. Nor shall we wonder to find the whales so much the most fitted for the sea, when we learn that they were already living in the water when we first meet with the great army of milk-givers (see p. 211) just after the Chalk Period, so that they have probably had a much longer spell of watery life than the seals and sea-cows, whose remains we only find later.

Yet even the seals are so much altered from anything we see on land, that few people would believe at first sight that they have the same skeleton as a bear. We need not leave the British shores to study these pretty creatures, for they still come to the coasts of Wales, Cornwall, and Ireland; while in the Hebrides they may be seen lying fast asleep on the rocks at low tide out at sea, one, placed higher than the rest, keeping awake as sentinel to give warning at the least approach of danger.

But if we begin our study with the common seal we shall be much puzzled, for he is very unlike a land animal. His round neckless body tapering away to the tail, where the hind flippers stretch out behind like fish's fins, reminds us far more of a tunny fish than of a four-footed milk-giver; while the front flippers, coming out so finlike from his side, give us very little idea of legs (see Fig. 81). No! in order to compare these fin-footed creatures with land animals we shall do far better to travel up to the Aleutian Islands at the entrance of Behring's Straits, and visit the Fur Seals and Sea Lions, from which we get our seal-skins, and the Walruses which sometimes lie there sleeping on the rocks, though their real home is farther north within the Arctic Circle, round the coasts of Nova Zembla, Spitzbergen, and Greenland.

These creatures, although they have "flippers," and are truly fin-footed, are much more like land animals than the smaller seals, for they plant their whole foot on the ground as a bear does, and walk, or, more properly, "flop along" on all fours. A mere glance at the skeleton of the sea lion, which is one of these higher kind of seals with a slight outer ear, ous, otos,  an ear), eared Seals.") ?> shows that it is a four-footed animal, with five toes to each foot, the great toes and the thumbs being the largest. We can see distinctly the short thighs and the long shanks, which give the hind flippers their lanky appearance, and we see, too, the broad stumpy arms, which give such strength to the front flippers in swimming. For the eared seals and walruses use their fore flippers very much in the water, while the true seals swim almost entirely with the hind flippers, and use the front ones chiefly for guiding themselves.

And now if we turn to the living fur seal we find that the reasons are twofold which make us forget that his limbs are legs. In the first place, the skin of his body comes down very low over his arms (see Fig. 81), while the hand is encased in skin, with only mere traces of nails upon it. Then as regards his hind legs, not only are the feet made into flippers, in which the toes are joined by a loose flexible skin, so that they can move them freely when swimming, but the legs themselves are strapped back by a skin passing right across his tail, so that his thighs are kept flat against his side, and only the lower part of the legs has power to move. We lose sight, then, of the limbs, and see very little more than the feet, which are disguised by being turned into flippers.

Now if we once think what is the object of a seal's life, this curious change in its body is at once explained. For seals are the hunters of the sea; fish-food is to them what flesh-food is to lions, wolves, and bears, only that they have a much wider field to hunt in, for they have the whole ocean for their feeding ground, and no one to dispute it with them but the sea-otter in places near the land, and the porpoises and other fish-feeding whales out at sea. In consequence of this we find seals of some kind in almost all parts of the world, except the Indian Ocean, though they evidently prefer the cooler regions. Even the large sea lions live in the North Pacific, as far up as the Aleutian Isles, and in the South Pacific down to the Falkland Islands and Kerguelen's Land, and play about the shores of the Cape, New Zealand, and Australia.

They have evidently been very successful in exchanging flesh-feeding for fish-feeding, and if we consider for a moment what changes a four-footed land animal would wish to make in its body in order to swim and dive in the water, we shall see that these changes have taken place in the seals.

First, a flexible body is required to wind and twist rapidly in the water, and this the seal arrives at by having the cushions of gristle between its joints very large and thick, while even its ribs are joined to its back by gristly rods, making its whole body very lissom. Next, a small head, offering little resistance to the water is an advantage, and this we find in all seals, while the short neck and extremely sloping narrow shoulders well encased in fat, make the body slope away gently with no jutting angles, but a round smooth surface from head to tail where it narrows like the tail of a fish. The next step is to do away with long angular arms and legs, which would impede it in diving and swimming, and here the seal meets the difficulty, not by losing its leg and arm bones, but by having them so shortened and encased in the skin that only the useful broad flippers are free, while the hind legs are set upon a very narrow hip joint (see Fig. So), so that they bend backwards and work close to the body. Lastly, such a warm-blooded animal would want clothing to prevent it from being chilled in icy cold water, and here we find two protections. First, under the skin is a layer of oily fat, which, while it reminds us of the fat accumulated by bears before they settle down to their winter's sleep, has become in the seals a dense oily mass, acting like a thick blanket in keeping up the warmth of the body; and secondly, the seal, like its distant relations the bears, has a dense furry covering, and over this a number of coarse long hairs, which give it that shining oily look we notice in all seals. No doubt every one has wondered, when watching seals in zoological gardens, where the fur can be which makes our sealskin muffs and jackets. The fact is, that this under fur is quite out of sight in the living seal, being covered by the coarse hairs; but if we could turn these aside, even in common seals, we should see the soft undergrowth beneath, and in the fur seals it is much thicker. Now the roots of these coarse hairs are deeper in the flesh than the roots of the soft undergrowth, and when the uppermost layer of the skin on which the fur grows is sliced off, the coarse hairs are cut away from their deep roots below, and can then be pulled out, leaving only the fur behind.

The seals then, while they are in all main points constructed like land animals, have gained many advantages, not by having new parts, but by the old ones becoming so modified as to make them admirably fitted for a watery life; and when we add that they have large eyes well adapted for seeing under water, keen ears with little or no outer ear, which would be useless, but a very acute hearing apparatus within, and nostrils which will close firmly and keep the air in and the water out when they dive, we must acknowledge that they make good use of all parts of their body. Indeed, their breathing apparatus is the most curious of all, for they can remain under water sometimes for twenty minutes, and meanwhile the circulation of their blood is probably controlled by large reservoirs in the veins, which prevent it going lungs back to the heart and luns till it can be purified by fresh breath.

Now, if all these changes from a land to a animal have been made gradually, we shall expect to find some forms less altered than others, and so it is. The Walrus, which is not a seal, but a creature with a thick hide having no fur and only a few scattered hairs upon it, and long tusks in his mouth, is much more of a land-animal than the seals. He passes a great part of his life sauntering along on the low shores of the Arctic seas, digging up mussels, cockles, and clams with his long canine teeth or tusks; and in accordance with this we find that his hind legs are much freer than even those of the sea-lions, for the skin binding them to his body is broader and his hips are stronger, so that, as he throws his front flippers forwards, he can also throw out his feet and walk on all fours in a strange straddling manner. He is remarkably fierce and strong, and Captain Scoresby caught one once in the act of killing and eating a large narwhal, so that they are evidently not afraid of attacking even large animals. The walrus is even said to stand at bay on shore and fight his great destroyer the polar bear, throwing up his head so as to strike forcibly with his sharp tusks, but in this battle he is generally defeated. His tusks alone would suggest that he lives a good deal on land exposed to dangers, for his more aquatic relations the seals are without tusks, and though their teeth are sharp enough, and they fight among themselves, yet their way of escaping the great tyrant of the ice-fields is to slip into the water.

Beyond his tusks, and the fact that by sleeping many weeks on the ice in autumn he reminds us of the bears, the walrus's life is not very interesting. They live in large shoals in the Arctic sea, climbing the rocks and ice with the help of their tusks, which they drive into the crevices and so haul themselves up. During the colder times just before our own, they came down into much lower latitudes than now, and we find their bones as far south as England in Europe and Virginia in America, and even in our day one has been seen off the west coast of Skye; but we know very little of their daily life or how they bring up their young ones.

Of Fur Seals and Sca Lions, however, we know a good deal, and a singular history it is. They spend the greater part of the year in huge shoals in the sea, rising and falling, gambolling and diving in the water, feeding on the fish, and probably migrating from colder to warmer seas in the winter from either pole. But the interesting time of their life is in the spring, when the northern eared seals have often been watched as they come to the shores of the Aleutian Isles to bring up their families.

For then begins the fight which seals shall get the most wives. Early in May the fathers begin to arrive—strong old seals, which have gone through the battle many years before and know the rules. They are huge fellows six or seven feet long, with enormous eye-teeth and cutting teeth next to them, which together grip like a vice. They come up at first singly and then in greater numbers, swimming powerfully and laying hold of the rocks with their flippers so as to haul themselves up on land, taking the best positions they can find on the edge of the water to watch for the arrival of the mothers. Yet still more and more fathers arrive as time goes on, and these are obliged to go farther inland, for all the shore stations are soon occupied, and each sea lion defends his own plot of ground with tooth and flipper.

Thus, in about a month's time, from the shore right inland, the whole island is covered with male seals. And now the mothers arrive, coming to the islands that their little ones may be born. They arc very much smaller, not much more than four feet long, lighter in colour than the fathers, gentle and inoffensive; and as they swim up to the island each father seal tries, by coaxing, pulling, and tugging, to persuade a mate to come on to his rock. If he succeeds he has then to keep her, for the sea lions behind, which cannot reach the sea, are on the watch to steal her.

Now he might make quite sure of his prize if he would be content with one, but he wants several; and the next young mother swimming up calls off his attention, and while he is courting her his neighbour behind tries to carry his first wife away, lifting her by the back of the neck as a cat does a kitten. Then often a terrible battle begins, and the poor mothers are pulled hither and thither till one male seal secures her, and then the whole thing begins again. This constant fighting and lovemaking go on for several days till all the sea lions have wives—those on the shore many, those behind perhaps very few. Then all settle down quietly, the little sea lions are born, bleating like young lambs, and family life begins. But the peace does not last long, for no sooner arc mothers able to leave their little ones than the old contest begins again, and happy the father who can keep his wives together through a whole season!

And now comes the most remarkable point. As a rule, seals are immense eaters, and they become very fat. But from the time that the fathers land upon the rocks till they go back to the water after about two months, they have never been known to leave their position to take food, so busy are they defending their wives. And when the two months are over, during which the little ones have been trying their strength in the waves and learning to swim, the fathers, which have grown thin and meagre, having used up all their fat, swim away and do not come back. The mothers, however, with the children, and those young bachelors, which have not yet taken wives, remain on the islands sporting and enjoying themselves till autumn, when they, too, start off for the open sea till spring comes round again.

Such is the history of the eared seals. And now that we have studied their form, and seen that their skeleton is like that of other animals, though their arms and legs are disguised as flippers, we shall understand our own home seals better; for the chief difference between them and the higher seals is merely that their front legs are much shorter, and that their hind legs are turned back so as to lie in a line with the body (see Fig. 81), while they are closely bound to the tail down right as far as the heel, so that they cannot throw their hind flippers forward nor use them in walking. Thus they have become still more completely aquatic animals, using their hind legs entirely in swimming, when they serve as great oars, working something like the screw of a steamer. The consequence is that they are terribly awkward on land, though they get along very fast by jerking their body forward, or sometimes by dragging themselves by their front flippers.

This, however, matters very little to them, for their home is the sea. True, they may often be seen lying asleep on sandbanks or on rocks jutting out of the water, but they rarely venture far up the land, always remaining where they can slip back into their true home at the least alarm. So they live in the seas almost all over the world. They may be known from the higher seals chiefly by their want of outer ears, their backward-turned legs, and their feet with both the great and little toes larger than the inner ones; but their life is much the same. Some live near our own shores, especially in Scotland; some are peculiar to Australia and New Zealand; others crowd the icy seas of Greenland, sleeping in large herds on the ice-fields, where the polar bear makes them his prey; while others again live on the pack ice round the South Pole, the huge Elephant seal, with its long tapir-like nose, basking on the shores of Kerguelen's Land and the islands of the southern seas—a monster twelve feet or more long, with his smaller wives beside him.

Thus the seals are bold ocean lovers, feeding entirely on animal food, and finding plenty of it in the wide sea as they roam. But there is another family of warm-blooded animals, pure vegetable-feeders, which also must have found their way in distant ages into the water; for they too are milk-givers, and though they have lost their hind legs, have still the front legs with all their proper bones, with the hands turned into flippers.

These animals are the curious sea-cows or Manatees, which wander under water along the east coast of Africa and west coast of South America, feeding in the bays and often up the rivers, on the sea-weeds and water-plants of all kinds; while another kind with tusks, called the Dugong, feeds all along the shores of the Indian Ocean and Australia.

It is strange that while every child knows something about seals, very few people have heard of these gentle grazing manatees and dugongs, the only large vegetable-feeders of the sea. Yet they are curious, interesting animals, and seem to be the forms which have given rise to the popular stories of mermaids, Sirenia,  a curious name for voiceless animals.") ?> for they suckle their young ones at the breast, clasping them with their flippers, and when they raise their heads in the water have something the appearance of an uncouth mother nursing her child.

But very uncouth indeed! for they are long barrel-shaped creatures, with a thick skin like the elephant's, with short stiff hairs upon it. Their head is small, with no outer ears, and very insignificant eyes surrounded with wrinkles; their lips are thick, heavy, and covered with short bristles, and above them two narrow nostrils open and close according as they are above or under water. Their front flippers, which are all they have, are long and broad, with faintly-marked flat nails upon them, and behind these their body tapers away gradually into a thin, wide, shovel-shaped tail, not set edgewise as in a fish, but across  the body, so as to lie like a broad leaf in the water.

Who would think that a creature like this had anything in common with land animals? Yet so it is, for not only do we know that his ancestors had traces of hind legs, but his front limbs are quite as true arms and hands as those of any of the seals. Moreover, he has large broad grinding back teeth like the elephant, and in front he has small cutting teeth as a baby, though these are covered up by the gum as he grows older. In the Australian dugong, however, these teeth continuo to grow and form good-sized tusks in the fathers.

What, then, is this curious animal? Simply a vegetable-feeder which has become fitted for a watery life—a gentle, peaceable animal, which keeps near the shore and grasps the seaweed with the sides of its upper lip, and then nips it off by a set of horny plates, which grow down from the roof of its mouth, and answer to the rough wrinkles on a cow's palate. They may often be seen together, father, mother, and child, wandering up the river Congo in Africa, or the Amazons in South America, feeding entirely under water, and only raising their heads from time to time with a snort to take in fresh air. In olden times they probably thronged all the coasts on the sea-margin, for a hundred and fifty years ago there was another group of them, the Rhytinas, right up in the cold seas of Behring's Straits, where the vast submarine forests of seaweed afforded them plenty of food. But the sailors found them such good eating, and the fatty blubber on their bodies was so valuable, that they were all killed twenty-five years after Bchring first discovered them, and unless some care is taken, the more southern sea-cows may some day be exterminated in the same way.

And now that we have firmly grasped the fact that the seals and manatees, however altered in shape, belong to the four-footed and milk-giving group, perhaps we shall be prepared to understand how it is that the whales cete,  a whale.") ?> are not fish, though this popular delusion is one of the most difficult to overcome. "Do you really mean then," exclaim nearly all people who are not naturalists, "that a whale is not a huge fish?" Certainly I do! A whale is no more a fish than crocodiles, penguins, or seals, are fish although they too live chiefly in the water.

A whale is a warm -blooded, air-breathing, milk-giving animal. Its fins are hands with finger-bones, having a large number of joints (see Fig. 84); its tail is a piece of cartilage or gristle, and not a fish's fin with bones and rays; it has teeth in its gums even if it never cuts them; and it gives suck to its little one just as much as a cow does to her calf (see Fig. 85). Nay! the whalebone whales have even the traces of hind legs entirely buried under the skin (see Fig. 84), and in the Greenland whale the hip-joint and knee-joint can be distinguished with some of their muscles, though the bones are quite hidden and useless.

We see then that the whale undoubtedly belongs to the same type as the four-footed land animals, although it branched off into thewater so long ago that it may have come from some very  early milk-giver. But why then has it become so like a fish? For the same reason that the penguin's wings have become so fin-like, and the seal's arms and legs have become fl i ppers, namely, that during the long time in which the whales have taken to a watery life, those which could swim best and float best in the water have been the most successful in the struggle for existence; and as a fish's shape is by far the best for this purpose the warm-blooded milk-giver has gradually imitated it, though belonging to quite a different order of animals.

We saw this imitation already beginning in the seals, with their bodies sloping off towards the tail and their legs fastened back in a line with the body; but they have not gone so far in this direction as the whales have, since they still have hind legs and furry bodies. The sea cows, on their line, have gone a little farther, for they have lost their hind legs, and their skin is smooth, with very few hairs upon it. But it remained for the whales to take up the best fish-form, the old spindle-shape, thinning before and behind, with the strong fleshy tail ending in two tail lobes, which act like a screw in driving the body along.

Any good drawing of a whale shows at once how admirably these animals are fitted for gliding through the water (see Fig. 85). True, many of them have enormous heads, but these always have long face-bones ending in a rounded point, and even the huge head of the sperm whale (see Fig. 87), eighteen feet long, six feet high, and six feet wide, is rounded off above, and gradually thins away below, like the cut-water of a ship. The eyes are very tiny and so little exposed, that it is difficult to find them; there are no outer ears, though the bones within are large and probably very useful for hearing in water; the bones of the neck are seven, as is the rule among milk-givers, but they are so flattened and firmly soldered together, and so covered with blubber, that there is not even a hollow between the head and the body; while to crown all, the skin is perfectly smooth so as to offer no resistance to the water. Here, however, would be a disadvantage in the loss of the furry covering, since most of the whales travel into cold seas, were it not compensated by the great mass of oily fat or blubber which fills the cells in the under part of the skin, and keeps the whole body warm; and thus the whale, by a covering of fat often as much as a foot and a half thick, solves the problem of a warm-blooded animal, with a smooth gliding body, living in icy water without having its blood chilled.

In every essential for swimming, then, whales are as well provided as any fish, while their immensely strong backbone, and the long cords or tendons running from the mass of muscle on the body to the tail, give them such tremendous power that a large whale makes nothing of tossing a whole boat's crew into the air and breaking the boat in two. But, though they are so far true water-animals, yet they cannot live entirely below as fish can, for they have no apparatus for water-breathing. The outside of their body takes on the appearance of a fish, but inside they have the true lungs, the four-chambered heart, and all the complicated machinery of a warm-blooded animal. Therefore, though a whale may dive deep and remain below to seek its food, yet before an hour has passed even the largest of them must come floating up to the top again, to blow out the bad air through the nostrils at the top of the head, and fill the capacious lungs with a fresh supply. It is then that, partly because of the water which has run into the blowhole, and partly because the rush of breath throws up spray from the sea, we see those magnificent spouts of water which tell that a whale is below. The older naturalists thought that these spouts were caused by the water which the whale had taken into its mouth; but this is not so, and Scoresby, the great Arctic traveller, states distinctly that if the blowhole of the whale is out of the water only moist vapour rises with the breath, while when it makes a large spout this comes from its blowing under water and so throwing up a jet.

If, however, the whale is a simple air-breather and y et swims under water with its mouth open, how comes it that this water does not run down the windpipe and choke the lungs? This is prevented by a most ingenious contrivance. At the top of our own windpipe there is a small elastic lid which shuts when we swallow, and prevents water and food from running down to the lungs. Now, in the whale the gristle answering to this lid runs up as a long tube past the roof of the mouth into the lower portion of the nose, and is kept there tightly, being surrounded by the muscles of the soft palate. The upper portion of the nose cavity then opens on the forehead by means of one or two "blowholes," as the outside nose holes are called; so that when the blowholes are closed the whale can swim with its mouth open and feed under water, and yet not a drop will enter its lungs.

A large sperm whale will often remain twelve minutes or more at the top of the water, taking in air at the single blowhole in the front of its head, and purifying its blood, and then with a roll and a tumble it will plunge down again, and remain for an hour below, trusting to a large network of blood-vessels lying between the lungs and the ribs to supply purified blood to its body and retain the impure blood till it comes up again to breathe.

But the smaller whales and porpoises, which play about our coasts, have to come up much more often, and even when they are not tumbling and jumping, as they love to do, you may see them rising at regular intervals as they swim along, their black backs appearing like little hillocks in the water, as they "blow" strongly from their single nose-slit, take a quick breath in, and sink again to rise a few paces farther on and repeat the process.

Thus provided both with swimming and breathing apparatus, these purely air-breathing animals wander over the wide ocean and live the lives of fish, making such good use of food which cannot be reached by land animals, or those which must keep near the shore, that we shall not be surprised to find that the whale family is a very large one.

But it is curious that the fierce animals of prey among them should be, not the huge whales but the smaller Dolphins, Porpoises, and Grampuses; and this shows how different water-feeding is to land-feeding, since, because the water is full of myriads of small and soft creatures, the sperm whale feeding on jelly-fish, and the large whalebone whale feeding on soft cuttle-fish and the minutest beings in the sea, are those which attain the largest size.

Most people have at one time or another seen a shoal of porpoises either out at sea or travelling up the mouth of some large river, where

and though they are small creatures, only about five feet long, they are very good examples of the whale shape, with their tapering bodies, broad tails, and the back fin, which is found in some whales and not in others. Sometimes they swim quietly, only rising to breathe, and then they work the tail gently from side to side; at others they gambol and frolic, and jump right out of the water, beating the tail up and down, and bending like a salmon when he leaps; and whether they come quietly or wildly, you may generally know they are near by the frightened mackerel and herrings, which spring out of the water to avoid them. For the porpoises have a row of sharp teeth in each jaw, more than a hundred in all, and they bite, kill, and swallow in one gulp, without waiting to divide their food, so that they make sad havoc among the fish.

They are here to-day and gone to-morrow. A few kinds wander up into fresh water, such as the Ganges and the Amazons, but by far the greater number range all over our northern seas, together with their near relations the dolphins, and the bottle-nosed whales, and the strange narwhal, with its two solitary eye teeth, one only of which grows out as a long tusk. All these roam freely through the vast ocean home, coming into the still bays to bring up their young ones, which they nurse and suckle tenderly, afterwards moving off again in shoals to the open sea. There they will follow the ships, and sport and play, and probably we shall never know exactly where their wanderings extend, though it seems that they prefer the northern hemisphere.

Among all the dolphin family the most voracious and bloodthirsty is the Grampus or Orca, which is commonly called the "Killer Whale," because it alone feeds on warm-blooded animals, seizing the seals with its strong, sharp, conical teeth, devouring even its own relations the porpoises, and attacking and tearing to pieces the larger whales. No lion or tiger could be more ruthless in its attacks than this large-toothed whale, which is sometimes as much as twenty-five feet long and has broad flippers. In vain even the mother walruses try to save their young ones by carrying them on their backs; the cunning Orca swims below her, and coming up with a jerk shakes the young one from its place of safety and swallows it in a moment. Nor do they merely fight single-handed, for many voyagers have seen them attack large whales in a pack like wolves, and in 1858 Mr. Scammon saw three killer whales fall upon a huge Californian Gray Whale and her young one, though even the baby whale was three times their size. They bit, they tore, and wounded them both till they sank, and the conquerors appeared with huge pieces of flesh in their mouths, as they devoured their prey. How much they can eat is shown by one orca having been killed which had the remains of thirteen porpoises and fourteen seals in its stomach!

How strange now to turn from this ravenous hunter to the huge Sperm Whale, eighty feet long, with a head one-third the size of its whole body and more than a ton of spermacetic oil in its forehead, and to think that this monster swims quietly along in the sea, drops its long thin lower jaw, and with wide-open mouth simply gulps in jelly-fish, small fish, and other fry, thus without any exertion or fuss slaying its millions of small and soft creatures quietly, as the orca does the higher creatures with so much battle and strife!

For the sperm whale (Fig. 87) must need a great deal of food to feed its huge body. Though it has forty-two teeth in the lower jaw it never cuts those in the upper one, and seems to depend more on sweeping its prey into its mouth than on attacking it. And this perhaps partly explains the use of that curious case of spermaceti which lies in its huge forehead over the tough fat of its upper jaw. For this oil gives out a powerful scent, which, when the whale is feeding below in the deep water, most probably attracts fish and other small animals, as they are also certainly attracted nearer the surface by the shining white lining of its mouth. This light mass is also, however, useful in giving the head a tendency to rise, so that when the whale wishes to swim quickly it has only to rise to the top, so that the bulk of its head will stand out of the water, the lower and narrow part cutting the waves. In this position he can go at the rate of twelve to twenty miles an hour.

But if the sperm whale is curious, as it carries its oil-laden head through all seas from pole to pole, chiefly in warmer latitudes, how much more so are the whalebone whales, which are monarchs of the colder and arctic seas, where they feed on the swarms of mollusca, crustaceans, and jelly animals which live there. For these large whales, though they have teeth in their gums, never cut them, but in their place they have large sheets of whalebone hanging down from the upper jaw (sec Fig. 84), smooth on the outside, fringed with short hairs on the inside, and crowded together so thickly, only about a quarter of an inch apart, that as many as three hundred sheets hang down on each side of the mouth of the great Greenland whale.

It is easy to see the use of these whalebones when we remember that this huge whale feeds entirely by filling its enormous mouth with water, and then closing it and raising its thick tongue at the back so as to drive the water out at the sides, straining it through the fine fringes, which fill up all the spaces between the plates and keep back every little shell-fish and soft animal. But it is less easy to guess where these whalebone plates come from, till we look back at the manatee, and remember those horny ridges which it uses for biting, and which are exaggerations of the rough fleshy ridges at the top of a cow's mouth.

Then we have a clue, for each blade of whalebone grows from a horny white gum, being fed by a fleshy substance below much in the same way as our nails are, so that these blades are, as it were, a series of hardened ridges, which grow out from the soft palate, till they become frayed at the edges, and form that dense fringe which is the whale's strainer, upon which he depends entirely for his food.

Explain it as we will, however, it is a most wonderful apparatus. Imagine a huge upper jaw forming an arch more than nine feet high, so that if the whalebone were cleared away a man could walk about inside, upon the thick tongue which lies in the lower jaw fastened down almost to the tip so that it cannot be put out of the mouth. And then remember that this enormous mouth has to be filled with food sufficient to nourish a body fifty or more feet long. Who would ever guess that this food is made up of creatures so small that countless millions must go to a mouthful? Yet the whole difficulty is solved simply by these triangular fringed plates or mouth-ridges (see section Fig. 84, p. 318), covered with horny matter and frayed into minute threads like the horny barbs of a feather.

Nor are we yet at the end of the wonderful for while the jaw is only from nine to twelve feet high, the long outside edge of the plates is often eighteen feet long, and for this reason, that if they were only as long as the jaw is deep, then when the whale went fishing with his mouth open the animals would escape below the fringe, while as they now are, he may gape as wide as he will, the long curtain will still guard the passage of the mouth and entangle the prey in its meshes. But what, then, is to become of this great length of whalebone when the animal shuts his mouth? Here comes in the use of the beautiful elasticity of the plates, for the great Arctic whaler, Captain Gray, has shown that as the mouth shuts the lower ends of the longer plates bend back towards the throat and fall into the hollow formed by the short blades behind them, so that the whole lies compactly fitted in, ready to spring open again, and fill the gap whenever the jaws are distended.

With this magnificent fishing-net the whalebone whales go a-fishing in all the salt waters of the world. They are not all of enormous size,—many of them are not more than twenty feet long,—nor have they all such a perfect mouthful of whalebone as the great Polar Whale; but when the whalebone is shorter, as in the Rorqual, and other whales with back fins, the stiff walls of the lower lip close in the sides of the mouth and prevent the escape of the prey; and many of these whales have a curious arrangement of skin folds under the lower jaw, which stretch out and enable them to take in enormous mouthfuls of water, so as to secure more food.

New Zealand, California, Japan, the Cape, the Bay of Biscay, and in fact almost every shore or sea from pole to pole, has some whale called by its name; for these gaping fishers are everywhere, and it is not always easy to say whether the same whale is not called by different names in various parts of the world. In the shallow bays and lagoons they may be found with their newly-born young ones very early in the year; while far out at sea ships meet with them travelling in shoals, or "schools," northwards, as the summer sets in and the Arctic Sea is swarming with life. In fact the Californian gray whales go right up into the ice, poking their noses up through the holes to breathe, and then they travel far away south again into the tropics to bring up their young ones.

And whether large or small, toothed whales or whalebone whales, active as the dolphin and the huge fin-whales or rorquals, which dash through the water although some are nearly a hundred feet long, or lazy and harmless as the Greenland whale is unless attacked, in one thing all the whale family betray their high place in the animal kingdom. Nowhere, either on land or in the water, can mothers be found more tender, more devoted, or more willing to sacrifice their lives for their children than whale-mothers. Scoresby tells us that the whalers, as means of catching the grown-up whales, will sometimes strike a young one with harpoon and line, sure that the mother will come to its rescue. Then she may be seen coming to the top with it encouraging it to swim away, and she will even take it under her fin, and, in spite of the harpoons of the whalers, will never leave it till life is extinct. Nay, she has been known to carry it off triumphantly, for the lash of her tail is furiously strong when she is maddened by the danger of her child, so that a boat's crew scarcely dare approach her.

And now there remains the question what enemies besides man these strong-swimming milk-givers can have in their ocean home? We have seen that the orca or killer whale will turn cannibal and devour those of its own kind, and the swordfish is said to attack whales with its formidable spear; but these are not their greatest enemies. With many of the whales it is tiny creatures like those on which they feed which hasten their death, for small parasitic crustaceans cover their head and fins, and feed upon their fat, so that whales which have been infested with these animals are often found to be "dry," or to have lost nearly all their oil. And thus we see the tables turned, and while the whale feeds upon minute creatures, it is in its turn destroyed by them.

Nevertheless, as a rule, they probably live long lives, till their teeth are worn, or their whalebone frayed and broken, and their blubber wasted away; and then, it may be after eighty or one hundred years of life, they die a natural death. Therefore they probably share with the elephant the longest term of life of any of the warm-blooded animals; and though their existence cannot certainly be said to be an exciting one, yet, when undisturbed by man, it is at least peaceful, sociable, and full of family love.

It may perhaps seem strange that we should have taken these ocean-dwellers last in our glimpses of animal life; but in the first place, how was it possible to show how they are truly related to the land mammalia until we understood the structure of these last? And in the second place, we have as out object to see how the backboned family have won for themselves places in the world, and surely there are none which have done this more successfully or in a more strange and unexpected way than the whales, which, while retaining all the qualities of warm-blooded animals, have won themselves a home in the ocean by imitating the form and habits of fish, and so adapting themselves to find food in the great oceans, where their land relations were po verless to avail themselves of it.