Concerning Animals and Other Matters - Edward Hamilton Aitken (adventure books to read .TXT) 📗

and hollow, and its upper edges turn in to meet each other, so that you may fairly describe it as a pipe with a narrow slit along the upper side. In this pipe lies the tongue, and it cannot get out, for it is wider than the slit, but it can be pressed against the top to close the slit, and then the lower jaw becomes an actual pipe. The root of the tongue is furnished on both sides with a loose fringe which we will call the first strainer. The upper jaw is thin and flat and rests on the lower like a lid, and it is beautifully fringed along both sides with small, leathery points, close set, like the teeth of a very fine saw. This is the second strainer. To work the machine you dip the point into dirty water full of water-fleas, draw back the tip of the tongue a little, and suck in water till the lower jaw (the pipe) is full, then close the point again with the tip of the tongue and force the water out. It can only get out by passing through the first strainers at the root of the tongue, then over the palate, and so through the second strainers at the sides of the bill; and all the solid matter it contained will remain in the mouth. The sucking in and squirting out of the water is managed by the cheeks, or rather by the cheek, for a flamingo has only one cheek, and that is situated under the chin. When the bird is feeding you will see this throbbing faster than the eye can follow it, while water squirts from the sides of the mouth in a continuous stream. I should have said that the whole bill is sharply bent downwards at the middle. The advantage of this is that when the bird lets down its head into the water, like a bucket into a well, the point of the bill does not stick in the mud, but lies flat on it, upside down.

In conclusion, let us not fail to note, whatever be our political creed, that, while all the birds pursue their respective industries, there sit apart, in pride of place, some whose bills are not tools wherewith to work, but weapons wherewith to slay. And these take tribute of the rest, not with their consent, but of right.


III


TAILS

The secrets of Nature often play like an iridescence on the surface, and escape the eye of her worshipper because it is stopped with a microscope. There are mysteries all about us as omnipresent as the movement of the air that lifts the smoke and stirs the leaves, which I cannot find that any philosopher has looked into. Often and deeply have I been impressed with this. For example, there is scarcely, in this world, a commoner or a humbler thing than a tail, yet how multifarious is it in aspect, in construction, and in function, a hundred different things and yet one. Some are of feathers and some of hair, and some bare and skinny; some are long and some are short, some stick up and some hang down, some wag for ever and some are still; the uses that they serve cannot be numbered, but one name covers them all. In the course of evolution they came in with the fishes and went out with man. What was their purpose and mission? What place have they filled in the scheme of things? In short, what is the true inwardness of a tail?

If we try to commence--as scientific method requires--with a definition, we stumble on a key, at the very threshold, which opens the door. For there is no definition of a tail; it is not, in its nature, anything at all. When an animal's fore-legs are fitted on to its backbone at the proper distance from the hind-legs, if any of the backbone remains over, we call it a tail. But it has no purpose; it is a mere surplus, which a tailor (the pun is unavoidable) would have trimmed off. And, lo! in this very negativeness lies the whole secret of the multifarious positiveness of tails. For the absence of special purpose is the chance of general usefulness. The ear must fulfil its purpose or fail entirely, for it can do nothing else. Eyes, nose and mouth, hands and feet, all have their duties; the tail is the unemployed. And if we allow that life has had any hand in the shaping of its own destiny, then the ingenuity of the devices for turning the useless member to account affords one of the most exhilarating subjects of contemplation in the whole panorama of Nature. The fishes fitted it up at once as a twin-propeller, with results so satisfactory that the whale and the porpoise, coming long after, adopted the invention. And be it noted that these last and their kin are now the only ocean-going mammals in the world. The whole tribe of paddle-steamers, such as seals and walruses and dugongs, are only coasters.

Among those beasts that would live on the dry land, the primitive kangaroo could think of nothing better to do with his tail than to make a stool of it. It was a simple thought, but a happy one. Sitting up like a gentleman, he has his hands free to scratch his ribs or twitch his moustache. And when he goes he needs not to put them to the ground, for his great tail so nearly equals the weight of his body that one pair of legs keeps the balance even. And so the kangaroo, almost the lowest of beasts, comes closer to man in his postures than any other. The squirrel also sits up and uses his forepaws for hands, but the squirrel is a sybarite who lies abed in cold weather, and it is every way characteristic of him that he has sent his tail to the furrier and had it done up into a boa, or comforter, at once warm and becoming. See, too, how daintily he lifts it over his back to keep it clean. The rat is a near relation of the squirrel zoologically, but personally he is a gutter-snipe, and you may know that by one look at the tail which he drags after him like a dirty rope. Others of the same family, cleaner, though not more ingenious, like the guinea-pig, have simply dispensed with the encumbrance; but the rabbit has kept enough to make a white cockade, which it hoists when bolting from danger. This is for the guidance of the youngsters. Nearly every kind of deer and antelope carries the same signal, with which, when fleeing through dusky woods, the leader shows the way to the herd and the doe to her fawn.

But of beasts that graze and browse, a large number have turned their tails rather to a use which throws a pathetic light on misery of which we have little experience. We do, indeed, growl at the gnats of a summer evening and think ourselves very ill-used. How little do we know or think of the unintermitted and unabated torment that the most harmless classes of beasts suffer from the bands of beggars which follow them night and day, demanding blood, and will take no refusal. Driven from the brow they settle on the neck, shaken from the neck they dive between the legs, and but for that far-reaching whisk at the end of the tail, they would found a permanent colony on the flanks and defy ejection, like the raiders of Vatersay. Darwin argues that the tail-brush may have materially helped to secure the survival of those species of beasts that possessed it, and no doubt he is right.

The subject is interminable, but we must give a passing glance to some quixotic tails. The opossum scampers up a tree, carrying all her numerous family on her back, and they do not fall off because each infant is securely moored by its own tail to the uplifted tail of its mother. The opossum is a very primitive beast, and so early and useful an invention should, one would think, have been spread widely in after time; but there appears to be some difficulty in developing muscles at the thin end of a long tail, for the animals that have turned it into a grasping organ are few and are widely scattered. Examples are the chameleon among lizards, our own little harvest mouse, and, pre-eminent above all, the American monkeys. To a howler, or spider-monkey, its long tail is a swing and a trapeze in its forest gymnasium. Humboldt saw (he says it) a cluster of them all hanging from a tree by one tail, which proceeded from a Sandow in the middle. I should like to see that too. It is worth noting, by the way, that no old-world monkey has attained to this application of its tail.

Then there is the beaver, whose tail I am convinced is a trowel. I know of no naturalist who has mentioned this, but such negative evidence is of little weight. The beaver, as everybody knows, is a builder, who cuts down trees and piles log upon log until he has raised a solid, domed cabin from seven to twenty feet in diameter, which he then plasters over with clay and straw. If he does not turn round and beat the work smooth with his tail, then I require to know for what purpose he carries that broad, heavy, and hard tool behind him.

How few even among lovers of Nature know why a frog has no tail! The reason-is simply that it used that organ up when it was in want. In early life, as a jolly tadpole, it had a flourishing tail to swim with, and gills for breathing water, and an infantile mouth for taking vegetable nourishment. But when it began to draw near to frog's estate, serious changes were required in its structure to fit it for the life of a land animal. Four tiny legs appeared from under its skin, the gills gave place to air-breathing lungs, and the infant lips to a great, gaping mouth. Now, during this "temporary alteration of the premises" all business was of necessity stopped. The half-fish, half-frog could neither sup like an infant nor eat like a man. In this extremity it fed on its own tail--absorbed it as a camel is said to absorb its hump when travelling in the foodless desert--and so it entered on its new life without one.

Aeronautics have changed the whole perspective of life for birds, as they may for us shortly; so it is no surprise to find that birds have, almost with one consent, converted their tails into steering-gear. A commonplace bird, like a sparrow, scarcely requires this except as a brake when in the act of alighting; but to those birds with which flight is an art and an accomplishment, an expansive forked or rounded tail (there are two patents) is indispensable. We have shot almost all the birds of this sort in our own country, and must travel if we would enjoy that enchanting sight--a pair of eagles or a party of kites gone aloft for a sail when the wind is rising, like skaters to a pond when the ice is bearing. For an hour on end, in restful ease or swift joy, they trace ever-varying circles and spirals against the dark storm-cloud, now rising, now falling, turning and reversing, but never once flapping their widespread pinions.

How is it done? How does the _Shamrock_ sail? Watch, and you will see. When the wind is behind, each stiff quill at the end of the wing stands out by itself and is caught and driven by the blast; but as the bird