In like manner, the monoculus delights in putrid waters; the gnat eats the monoculus; the frog eats the gnat; the pike eats the frog; and the sea-calf eats the pike.

The bat and the goat-sucker make their excursions only at night, that they may catch the moths, which at that time fly about in great quant.i.ties.

The woodp.e.c.k.e.r pulls out the insects which lie hid in the trunks of trees.

The swallow pursues those which fly about in the open air. The mole feeds on worms and grubs in the earth. The large fishes devour the small ones.

And perhaps there is not an animal in existence, which has not an enemy to contend with.

Among quadrupeds, wild beasts are most remarkably pernicious and dangerous to others. But that they may not, by their cruelty, destroy a whole species, these are circ.u.mscribed within certain bounds: as to the fiercest of them, they are few in number, when compared with other animals; sometimes they fall upon and destroy each other; and it is remarked also, that they seldom live to a great age, for they are subject, from the nature of their diet, to various diseases, which bring them sooner to an end than those animals which live on vegetables. It has been asked, why has the Supreme Being const.i.tuted such an order in nature, that, it should seem, some animals are created only to be destroyed by others? To this it has been answered, that Providence not only aimed at sustaining, but also keeping a just proportion amongst all the species, and so preventing any one of them from increasing too much, to the detriment of men and other animals. For if it be true, as it a.s.suredly is, that the surface of the earth can support only a certain number of creatures, they must all perish, if the same number were doubled or trebled.

There are many kinds of flies, which bring forth so abundantly, that they would soon fill the air, and, like clouds, intercept the light of the sun, unless they were devoured by birds, spiders, and other animals.

Storks and cranes free Egypt from frogs, which, after the inundation of the Nile, cover the whole country. Falcons clear Palestine from mice.

Bellonius, on this subject, says, "The storks come to Egypt in such abundance, that the fields and meadows are quite white with them. Yet the Egyptians are not displeased with them, as frogs are generated in such numbers, that, did not the storks devour them, they would over-run every thing. Besides, they also catch and eat serpents. Between Belba and Gaza, the fields of Palestine are often injured by mice and rats; and were these vermin not destroyed by the falcons, that come here by instinct, the inhabitants could have no harvest."

The white fox is of equal advantage in the Lapland Alps; as he destroys the Norway rat, which, by its prodigious increase, would otherwise entirely destroy vegetation in that country.

It is sufficient for us to believe that Providence is wise in all its works, and that nothing is made in vain. When rapacious animals do us mischief, let us not think that the Creator planned the order of nature according to our private principles of economy; for the Laplander has one way of living, the European husbandman another, and the Hottentot differs from them both; whereas the stupendous Deity is one throughout the globe; and if Providence do not always calculate according to our method of reckoning, we ought to consider this affair in the same light as when different seamen wait for a fair wind, every one with respect to the port to which he is bound: these we plainly see cannot all be satisfied.

We shall conclude this branch, by turning once more to Man, and tracing him through his progressive stages of decay, until death puts a final period to his earthly existence.

The human form has no sooner arrived at its state of perfection, than it begins to decline. The alteration is at first insensible, and often several years are elapsed before we find ourselves grown old. The news of this unwelcome change too generally comes from without; and we learn from others that we grow old, before we are willing to believe the report.

When the body is come to its full height, and is extended into its just dimensions, it then also begins to receive an additional bulk, which rather loads than a.s.sists it. This is formed of fat, which, generally, at about the age of forty, covers all the muscles, and interrupts their activity. Every exertion is then performed with greater labour, and the increase of size only serves as the forerunner of decay.

The bones also become every day more solid. In the embryo they are almost as soft as the muscles and the flesh, but by degrees they harden, and acquire their proper vigour; but still, for the purpose of circulation, they are furnished through all their substance with their proper ca.n.a.ls.

Nevertheless, these ca.n.a.ls are of very different capacities during the different stages of life. In infancy they are capacious, and the blood flows almost as freely through the bones as through any other part of the body; in manhood their size is greatly diminished, the vessels are almost imperceptible, and the circulation is proportionably slow. But in the decline of life, the blood which flows through the bones, no longer contributing to their growth, must necessarily serve to increase their hardness. The channels which run through the human frame may be compared to those pipes that we see crusted on the inside, by the water, for a long continuance, running through them. Both every day grow less and less, by the small rigid particles which are deposited within them. Thus, as the vessels are by degrees diminished, the juices also, which circulate through them, are diminished in proportion; till at length, in old age, these props of the human frame are not only more solid, but more brittle.

The cartilages, likewise, grow more rigid; the juices circulating through them, every day contribute to make them harder, so that those parts which in youth are elastic and pliant, in age become hard and bony, consequently the motion of the joints must become more difficult. Thus, in old age, every action of the body is performed with labour, and the cartilages, formerly so supple, will now sooner break than bend.

As the cartilages acquire hardness, and unfit the joints for motion, so also that mucous liquor, which is always secreted between the joints, and which serves, like oil to a hinge, to give them an easy and ready play, is now grown more scanty. It becomes thicker and more clammy, more unfit for answering the purposes of motion, and from thence, in old age every joint is stiff and awkward. At every motion this clammy liquor is heard to crack; and it is not without a great effort of the muscles, that its resistance is overcome. Old persons have been known, that seldom moved a single joint without thus giving notice of the violence that was done to it.

The membranes that cover the bones, joints, and the rest of the body, become, as we grow old, more dense and more dry. Those which surround the bones soon cease to be ductile. The fibres, of which the muscles or flesh is composed, become every day more rigid; and while, to the touch, the body seems, as we advance in years, to grow softer, it is in reality increasing in hardness. It is the skin, and not the flesh, that we feel on such occasions. The fat, and the flabbiness of it, seem to give an appearance of softness, which the flesh itself is very far from having.

None can doubt this after trying the difference between the flesh of young and old animals. The first is soft and tender, the last is hard and dry.

The skin is the only part of the body that age does not harden; that stretches to every degree of tension; and we have often frightful instances of its pliancy, in many disorders which are incident to humanity. In youth, while the body is vigorous and increasing, it continues to give way to its growth. But although it thus adapts itself to our increase, its does not in the same manner conform to our decay. The skin, in youth and health, is plump, glossy, veined, and clear; but when the body begins to decline, it has not elasticity enough to shrink entirely with its diminution; it becomes dark or yellow, and hangs in wrinkles, which no cosmetic can remove. The wrinkles of the body in general proceed from this cause; but those of the face seem to proceed from another, namely, from that variety of positions into which it is put by the speech, the food, or the pa.s.sions. Every grimace, every pa.s.sion, and every gratification of appet.i.te, puts the visage into different forms.

These are visible enough in young persons; but what at first was accidental or transitory, becomes, by habit, unalterably fixed in the visage as it grows older.

Hence, as we advance in age, the bones, the cartilages, the membranes, the flesh, and every fibre of the body, becomes more solid, more dry, and more brittle. Every part shrinks, motion becomes more slow, the circulation of the fluids is performed with less freedom; perspiration diminishes; the secretions alter; the digestion becomes laborious; and the juices no longer serve to convey their accustomed nourishment. Thus the body dies by little and little, and all its functions are diminished by degrees; life is driven from one part of the frame to another; universal rigidity prevails; and death, at last, seizes upon the remnant that is left.

As the bones, the cartilages, the muscles, and all other parts of the body, are softer in women than in men, these parts must, of consequence, require a longer time to arrive at that state of hardness which occasions death. Women, therefore, ought to be longer in growing old than men, and this is, generally speaking, the case. If we consult the tables which have been drawn up respecting human life, we shall find that, after a certain age, they are more long-lived than men, all other circ.u.mstances the same.

Thus a woman of sixty has a greater probability, than a man of the same age, of living till eighty.

We shall close this chapter with an account of ANIMAL REPRODUCTIONS.

Here we discover a new field of wonders, that seems entirely to contradict the principles that we had adopted concerning the formation of organized bodies. It was long thought that animals could only be multiplied by eggs, or by young ones. But it is now found that there are some exceptions to this general rule, since certain animal bodies have been discovered, that may be divided into as many complete bodies as you please; for each part thus separated from the parent body, soon repairs what is deficient, and becomes a complete animal. It is now no longer doubtful that the polypus belongs to the cla.s.s of animals, though it much resembles plants, both in form, and in its mode of propagating. The bodies of these creatures may be either cut across or longitudinally, and the pieces will become so many complete polypi. Even from the skin, or least part, cut off from the body, one or more polypi will be produced; and if several pieces cut off be joined together by the extremities, they will perfectly unite, nourish each other, and become one body. This discovery has given rise to other experiments, and it has been found that polypi are not the only animals which live and grow after being cut in pieces. The earth-worm will multiply after being cut in two; to the tail there grows a head, and the two pieces then become two worms. After having been divided, they cannot be joined together again; they remain for some time in the same state, or grow rather smaller; we then see at the extremity which was cut, a little white b.u.t.ton begin to appear, which increases and gradually lengthens.

Soon after, we may observe rings at first very close together, but insensibly extending on all sides; a new stomach, and other organs, are then formed. We may at any time make the following experiment with snails: cut off their heads close by the horns, and in a certain s.p.a.ce of time the head will be reproduced. A similar circ.u.mstance takes place in crabs; if one of their claws is torn off, it will again be entirely reproduced.

A very remarkable experiment was made by Duhamel, on the thigh of a chicken. After the thigh-bone which had been broken was perfectly restored, and a callus completely formed, he stripped off the flesh down to the bone;--the parts were gradually reproduced, and the bone, and the circulation of the blood, again renewed. We know then that some animals may be multiplied by dividing them into pieces; and we no longer doubt that the young of certain insects may be produced in the same manner as a branch is from a tree; that, being cut in pieces, they will live again in the smallest piece; that they may be turned inside out like a glove, divided into pieces, then turned again, and yet live, eat, grow, and multiply. Here a question offers itself, which perhaps no naturalist can resolve in a satisfactory manner: How does it happen that the parts thus cut off, can be again reproduced? We must suppose that germs are distributed to every part of the body; whilst in other animals they are only contained in certain parts. These germs unfold themselves when they receive proper nourishment. Thus, when an animal is cut in pieces, the germ is supplied with the necessary juices, which would have been conveyed to other parts, if they had not been diverted into a different channel.

The superfluous juices develop those parts which without them would have continued attached to each other. Every part of the polypus and worm, contains in itself, as the bud does the rudiments of a tree, all the viscera necessary to the animal. The parts essential to life are distributed throughout the body, and the circulation is carried on even in the smallest particles. As we do not understand all the means that the Author of nature makes use of to distribute life and feeling to such a number of animals, we have no reason to maintain, that the creatures of which we have been speaking, are the only ones that are exceptions to the general rule in their mode of propagating. The fecundity of nature, and the infinite wisdom of the Creator, always surpa.s.s our feeble conceptions.

The same hand that has formed the polypus and the worm, has shewn us that it is able to simplify the structure of animals.

CHAP. XIII.

CURIOSITIES RESPECTING ANIMALS.--(_Continued._)

_The Beaver, and its Habitations--The Mole--The Frog--The Toad--The Rhinoceros--Crocodiles and Alligators--Fossil Crocodile--The Ornithorhynchus Paradoxus--The Marmot, or Mountain Rat, of Switzerland._

Nature's unnumber'd family combine In one beneficent, one vast design; E'en from inanimates to breathing man,-- A heaven-conceiv'd, heaven-executed plan; Onward, from those who soar or lowly creep, The wholesome equipoise through all to keep, As faithful agents in earth, sea, and air, The lower world to watch with constant care; Her due proportion wisely to conserve:-- A wondrous trust, from which they never swerve.

_Pratt._

It would not be consistent with the plan of this work to embrace the whole natural history of the animal and vegetable kingdom. This is a Book of Curiosities; and it is our intention to present the reader with a sketch of the most remarkable things in the universe: our present subject, therefore, being curiosities respecting animals, we shall commence with--

THE BEAVER.--This animal was known to the ancients for its possession of that sebaceous matter called castor, secreted by two large glands near its genitals and a.n.u.s, and of which each animal has about two ounces; but they appear to have been unacquainted with its habits and economy, with that mental contrivance and practical dexterity, which in its natural state so strikingly distinguish it. Beavers are found in the most northern lat.i.tudes of Europe and Asia, but are most abundant in North America.

In the months of June and July, they a.s.semble in large companies to the number of two hundred, on the banks of some water, and proceed to the formation of their establishment. If the water be subject to risings and fallings, they erect a dam, to preserve it at a constant level; where this level is naturally preserved, this labour is superseded. The length of this dam is occasionally eight feet. In the preparation of it, they begin with felling some very high, but not extremely thick tree, on the border of a river, which can be made to fall into the water; and, in a short time, this is effected by the united operation of many, with their fore-teeth, the branches being afterwards cleared by the same process. A mult.i.tude of smaller trees are found necessary to complete the fabric, and many of these are dragged from some distance by land, and formed into stakes; the fixing of which is a work of extreme difficulty and perseverance, some of the beavers with their teeth raising their large ends against the crossbeam, while others at the bottom dig with their fore-feet the holes in which the points are to be sunk. A series of these stakes, in several rows, is established from one bank of the river to the other, in connection with the cross-tree, and the intervals between them are filled up by vast quant.i.ties of earth, brought from a distance, and plashed with materials adapted to give it tenacity, and prevent its being carried off. The bark is formed at the bottom, of about the width of twelve feet, diminishing as it approaches the surface of the water, to two or three; being thus judiciously constructed to resist its weight and efforts by the inclined plane instead of perpendicular opposition.

These preparations, of such immense magnitude and toil, being completed, they proceed to the construction of their mansions, which are raised on piles near the margin of the stream or lake, and have one opening from the land, and another by which they have instant access to the water. These buildings are usually of an orbicular form, in general about the diameter of ten feet, and comprehending frequently several stories. The foundation walls are nearly two feet in thickness, resting upon planks or stakes, which const.i.tute also their floors. In the houses of one story only, the walls, which in all cases are plastered with extreme neatness both externally and within, after rising about two feet perpendicularly, approach each other, so as at length to const.i.tute, in closing, a species of dome. In the application of the mortar to their habitations, the tails as well as feet of the beavers are of essential service. Stone, wood, and a sandy kind of earth, are employed in their structures, which, by their compactness and strength, completely preclude injury from winds and rain.

The alder, poplar, and willow, are the princ.i.p.al trees which they employ; and they always begin their operations on the trunk, at nearly two feet above the ground; nor do they ever desist from the process till its fall is completed. They sit instead of stand, at this labour, and while reducing the tree to the ground, derive a pleasure at once from the success of their toils, and from the gratification of their palate and appet.i.te by the bark, which is a favourite species of food to them, as well as the young and tender parts of the wood itself.

For their support in winter, ample stores are laid up near each separate cabin; and occasionally to give variety and luxury to their repasts during a long season, in which their stores must have become dry and nearly tasteless, they will make excursions into the neighbouring woods for fresh supplies. Depredations by the tenants of one cabin on the magazines of another are unknown, and the strictest notions of property and honesty are universal. Some of their habitations will contain six only, others twelve, and some even twenty or thirty inhabitants; and the whole village or township contains in general about twelve or fourteen habitations.

Strangers are not permitted to intrude on the vicinity; but, amidst the different members of the society itself, there appears to prevail that attachment and that friendship which are the natural result of mutual co-operation, and of active and successful struggles against difficulty.

The approach of danger is announced by the violent striking of their tails against the surface of the water, which extends the alarm to a great distance; and, while some throw themselves for security into the water, others retire within the precincts of their cabins, where they are safe from every enemy but man.

The neatness as well as the security of their dwellings is remarkable, the floors being strewed over with box and fir, and displaying the most admirable cleanness and order. Their general position is that of sitting, the upper part of the body, with the head, being considerably raised, while the lower touches, and is somewhat indeed immersed in, the water.

This element is not only indispensable to them in the same way as to other quadrupeds, but they carefully preserve access to it even when the ice is of very considerable depth, for the purpose of regaling themselves by excursions to a great extent under the frozen surface. The most general method of taking them is by attacking their cabins during these rambles, and watching their approach to a hole dug in the ice at a small distance, to which they are obliged, after a certain time, to resort for respiration.

If a man, who had never been informed of the industry of beavers and their manner of building, were shewn the edifices that they construct, he would suppose them to be the work of most eminent architects. Every thing is wonderful in the labours of these amphibious animals; the regular plan, the size, the solidity, and the admirable art of these buildings, must fill every attentive observer with astonishment.

The works of beavers have a great resemblance to those of men; and upon their first appearance we may imagine them to be produced by rational and thinking beings; but when we examine them nearer, we shall find that in all their proceedings, these animals do not act upon the principles of reason, but by an instinct which is implanted in them by nature. If reason guided their labours, we should naturally conclude that the buildings which they now construct would be very different from those they formerly made, and that they would gradually advance towards perfection. But we find that they never vary in the least from the rules of their forefathers, never deviate from the circle prescribed to them by nature, and the beavers of to-day build exactly after the same plan as those which lived before the deluge. But they are not the less worthy of our admiration. In these sagacious creatures we have an example of the great diversity there is in the instinct of animals--how superior is the instinct of the beaver to that of the sheep!

The flesh of the anterior part of the bodies of beavers resembles that of land animals in substance and flavour; while that of the lower possesses the taste, and smell, and lightness of fish.

The s.e.xual union among these animals is connected with considerable individual choice, sentiment, and constancy.--Every couple pa.s.s together the autumn and winter, with the most perfect comfort and affection. About the close of winter, the females, after a gestation of four months, produce, in general, each two or three young, and soon after this period they are quitted by the males, who ramble into the country to enjoy the return of spring; occasionally returning to their cabins, but no longer dwelling in them. When the females have reared their young, which happens in the course of a few weeks, to a state in which they can follow their dams, these also quit their winter residence, and resort to the woods, to enjoy the opening bloom and renovated supplies of nature. If their habitations on the water should be impaired by floods, or winds, or enemies, the beavers a.s.semble with great rapidity to repair the damage. If no alarm of this nature occurs, the summer is princ.i.p.ally spent by them in the woods, and on the advance of autumn they a.s.semble in the scene of their former labours and friendships, and prepare with a.s.siduity for the confinement and rigours of approaching winter.

When taken young, the beaver may be tamed without difficulty; but it exhibits few or no indications of superior intelligence. Some beavers are averse to that a.s.sociation which so strikingly characterizes these animals in general, and satisfy themselves with digging holes in the banks of rivers, instead of erecting elaborate habitations. The fur of these is comparatively of little value.

Another subject of animal curiosity is, THE MOLE.--This animal is about six inches in length, without the tail. Its body is large and cylindrical, and its snout strong and cartilaginous. Its skin is of extraordinary thickness, and covered with a fur, short, but yielding to that of no other animal in fineness. It hears with particular acuteness, and, notwithstanding the popular opinion to the contrary, possesses eyes, which it is stated to be able to withdraw or project at pleasure. It lives partly on the roots of vegetables, but princ.i.p.ally on animal food, such as worms and insects, and is extremely voracious and fierce. Shaw relates, from Sir Thomas Brown, that a mole, a toad, and a serpent, have been repeatedly inclosed in a large gla.s.s vase, and that the mole has not only killed the others, but has devoured a very considerable part of them. It abounds in soft ground, in which it can dig with ease, and which furnishes it with a great supply of food. It forms its subterraneous apartments with great facility by its snout and feet, and with a very judicious reference to escape and comfort. It produces four or five young in the spring, in a nest a little beneath the surface, composed of moss and herbage. It is an animal injurious to the grounds of the farmer, by throwing up innumerable hills of mould, in the construction of its habitation, or the pursuit of its food, and many persons obtain their subsistence from the premiums, which are, on this account, given for their destruction. Moles can swim with considerable dexterity, and are thus furnished with the means of escape in sudden inundations, to which they are frequently exposed. In Ireland, the mole is unknown.

THE COMMON FROG.--This is an animal so well known, that it needs no description: but some of its properties are very singular. Its spring, or power of taking large leaps, is remarkably great, and it is the best swimmer of all four-footed animals. Its parts are finely adapted for those ends, the fore members of the body being very lightly made, the hind legs and thighs very long, and furnished with very strong muscles. While in a tadpole state, it is entirely a water animal, for in this element the sp.a.w.n is cast. As soon as frogs are released from their tadpole state, they immediately take to land; and if the weather has been hot, and there fall any refreshing showers, the ground for a considerable s.p.a.ce is perfectly blackened by myriads of these animalcules, seeking for some secure lurking places. Some persons not taking time to examine into this phenomenon, imagined them to have been generated in the clouds, and showered on the earth: but had they, like Mr. Derham, traced them to the next pool, they would have found a better solution of the difficulty. As frogs adhere closely to the backs of their own species, so we know they will do the same by fish. That they will injure, if not entirely kill carp, is a fact indisputable, from the following relation.