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EMBRYO

CHICKEN.

A magnified embryo of the chick, four lines long; time, middle of the third day. b, c, a, represents the hemispheres of the brain; e, the cerebellum and medulla oblongata; h, h, vertebral lamina; i, ventricle of the heart; m, m, arteries of the blastoderma; o, o, boundaries of the abdomen; g, opening of the ear; the eye, formed first with a wide cleft. This also resembles, in all respects, the human embryo, at the same stage of development, but at a much later period.

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ross. She was kept in confinement for a night and a day; when seeming perfectly contented, she was let out into the yard, where she set about adjusting herself for some time; she then suddenly took wing, and in the course of a few hours was among her old companions in Annandale. She was a second time conveyed to Fife, and her wings clipped.

She continued perfectly happy, to appearance, till her feathers grew, when she again bade her new friends farewell. She was shot in the neighbourhood of Biggar, by a gentleman, who communicated the circumstance to the owner, whose name he learned from the collar that was found about her neck, containing his name and place of abode.

FORMATION OF THE CHICK IN THE EGG.-Scarcely has the hen sat upon the eggs twelve hours, before some lineaments of the head and body of the chick are discernible in the embryo; at the end of the second day, the heart begins to beat, but no blood is to be seen. In forty-eight hours we may distinguish two vesicles with blood, the pulsation of which is evident; one of them is the left ventricle, the other, the root of the great artery; soon after, one of the auricles of the heart is perceptible, in which pulsation may be remarked as well as in the ventricle. So early as the seventh hour, the wings may be distinguished, and on the head two globules for the brain, one for the beak, and two others for the front and hind part of the head. Towards the end of the fourth day, the two auricles, now distinctly visible, approach nearer the heart than they did before. About the fifth day the liver may be perceived; at the end of one hundred and thirty-eight hours, the lungs and stomach become visible; and in a few hours more, the intestines, veins, and upper jaw. On the seventh day, the brain begins to assume a more consistent form. One hundred and ninety hours after incubation, the beak opens, and flesh appears on the breast. In two hundred and ten, the ribs are formed, and the gall-bladder is visible. The bile, in a few hours more, is seen of a green colour; and if the chick be separated from its coverings, it will be seen to move. The feathers begin to shoot towards the two hun dred and fortieth hour, and at the same time the skull becomes cartilaginous; in twenty-four hours more, the eyes appear; at the two hundred and eighty-eighth, the ribs are perfected; and at the three hundred and thirty-first, the lungs, the stomach, and the breast, assume their natural appearance. On the eighteenth day of incubation, the first faint piping of the chick is heard. It then continually increases in size and in strength till it emerges from its prison.

By so many different gradations does the adorable wisdom of God conduct these creatures into life; all their progressive

evolutions are arranged with order, and there are none with out sufficient cause. If the liver is always formed on the fifth day, it is from the preceding state of the chick. No part of its body could appear sooner or later, without some injury to the embryo, and each of its members appears at the most convenient moment. The wise and invariable order in the production of this little body, is evidently the work of supernal power; and we shall be more convinced of it, if we consider the manner in which the chick is formed from the parts which compose the egg.

How admirable is that principle of life, the source of a new being, contained in the egg; all the parts of the animal being, invisible till they become developed by warmth! What a wonderful order and regularity is observed in this amazing process, the same evolutions taking place at once in twenty eggs! Neither does changing the position of the egg at all injure the embryo, or retard the formation of the chick; which, at the time when it breaks the shell, is found to be heavier than the whole egg was at first. These, however admirable, are far from being all the wonders displayed in the progress of incubation. The microscope, and the penetrating investigations of the curious, have only discovered what comes more immediately under the observation of our senses; whilst the discovery of many things remains for those who are to follow us, or perhaps they may never be known in this state of our existence. Much might be asked concerning the mystery connected with the formation of animal bodies, which at present is impenetrable to our researches; but let not this discourage us; let us only endeavour to improve, and make a good use of, the little knowledge we are permitted to acquire, and we shall have a sufficiency to discover at every step the wisdom and power of God, and enough to employ for the benefit of our fellow-creatures.

CHAP. XXI

CURIOSITIES RESPECTING BIRDS.-Concluded.)

Birds' Nests-Migration of Birds-Curious Method of Bird Catching in the Faro isles-Song of Birds.

BIRDS' NESTS

It wins my admiration,

To view the structure of that little work,
A bird's nest: mark it well within, without;
No tool had he that wrought, no knife to cut,
No nail to fix, no bodkin to insert,
No glue to join! his little beak was all;
And yet how neatly finish'd!

Hurdis.

THE structure of Bird's Nests discovers to us many curious objects, which cannot be uninteresting to the reflecting mind. And who does not admire those little regular edifices composed of so many different materials, collected and arranged with so much pains and skill, and constructed with so much industry, elegance, and neatness, with no other tools than a bill and two feet? That men can erect great buildings according to certain rules of art, is not surprising, when we consider that they enjoy the reasoning faculty, and that they possess tools and instruments of various kinds, to facilitate their work; but that a delicate little bird, in want of almost every thing necessary for such an undertaking, with only its bill and claws, should know how to combine so much skill, regularity of form, and solidity of composition, in constructing its nest, is truly wonderful, and never enough to be admired. We shall therefore consider it more minutely.

Nothing is more curious than the nest of a goldfinch or a chaffinch. The inside of it is lined with cotton, wool, and fine silky threads, while the outside is interwoven with thick moss; and that the nest may be less remarkable, and less exposed to the eye of observers, the colour of the moss resembles that of the bark of the tree, or of the hedge, where the nest is built. In some nests, the hair, the down, and the straws, are curiously laid across each other, and interwoven together. There are others, all the parts of which are neatly joined and fastened together by a thread which the bird makes of flax, horse or cow hair, and often of spiders' webs. Other birds, as the blackbird and the lapwing, after having constructed their nest, plaster the outside with a thin coating of mortar, which cements and binds together all the lower parts. and which, with the help of some cow-hair or moss, stuck to

it whilst the plaster is wet, keeps it compact and warm. The nests of swallows are differently constructed from the rest. They use neither sticks, straws, nor strings; but they compose a sort of cement, with which they make themselves nests, perfectly neat, secure, and convenient. To moisten the dust of which they form their nests, they frequently skim over the surface of some lake or river, and, dipping their breasts into the water, shake their wet feathers upon the dust till it is sufficiently moist, and then knead it up into a kind of clay with their bills.

But the nests most worthy of our admiration are those of certain Indian birds, which suspend them with great art from the branches of trees, that they may be secure from the pursuit of several animals and insects. In general, each species of bird has a peculiar mode of fixing its nest; some build them on houses, others in trees, some in the grass, others on the ground, and always in that way which is most adapted for the rearing of their young, and the preservation of their species. Such, therefore, is the wonderful instinct of birds, even in the structure and disposition of their nests alone, that we may safely conclude they cannot be mere inachines. But is it not also apparent, that in all their works they propose to themselves certain ends? They construct their nests hollow, forming the half of a sphere, that the heat may be more concentric. The nest is covered without by substances more or less coarse, not only to serve as a foundation, but to prevent the wind and insects from entering Within, it is lined with the most delicate materials, such as wool and feathers, that the nestlings may be soft and warm. Is it not something nearly approaching to reason, which teaches the bird to place its nest in such a manner as to be sheltered from rain, and out of the reach of destructive animals? Where have they learned that they are to produce eggs, which will require a nest to prevent them from being broken, and to keep them in the necessary temperature? that the heat would not be sufficiently concentrated if the nest were larger; and that, if it were smaller, all the young ones could not be contained in it? Who has taught them not to mistake the time, but to calculate so exactly, that the eggs are not laid before the nest is finished? These ques tions have never been satisfactorily answered, neither can this mystery in nature be clearly explained; all we can do is, to refer it to an instinct, which some animals seem to possess in a manner almost equal to reason and instinct to them is much more happy and beneficial than reason would be; for they seem to enjoy all the sweets of life without their moments being imbittered by the consideration of their inferior rank in the creation, and without the pain of anticipating evil.

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