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perch, rocked by the winds, without the necessity of watchful attention, in short, without any exercise of volition at all.

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The body of birds is strong and compact; the ribs are firm, and possess little mobility; the breast-bone, or sternum, is of considerable extent, and its surface is further increased by a large and deep keel, or projecting portion, which runs down the middle, on its external aspect. The size of the breast bone and the developement of the keel are in relation to the powers of flight, for it is on this part that the muscles of flight are situated. The neck is long, and from the number of distinct vertebræ composing it (varying from nine to twenty-three) enjoys great flexibility. The head, in comparison with the size of the body, is small; and that part which we should call the face is almost wholly occupied by the orbits of the eyes, organs which, in the feathered tribes, are very large. The jaws are extended into two projecting mandibles, covered with horn, and form what is termed the beak. The skull is articulated to the first vertebra of the neck by a single point, the occipital condyle, whence is allowed the utmost latitude of rotatory motion.

Birds are either carnivorous, omnivorous, insectivorous, or granivorous, and their digestive apparatus is modified accordingly. The crop, which is a dilated sack, at the extremity of the gullet, leads by a canal into a second stomach, the commencing portion of which is surrounded by a zone of gastric glands, pouring out a solvent fluid.

This portion is termed the ventriculus succenturiatus, and leads, in granivorous birds, into a powerful gizzard, composed of two muscles, surrounding a cavity lined with thick tough membrane ; the action of these muscles is a grinding motion, with pressure on each other, like two mill-stones, and the effect is a reduction of grain and vegetable matter into a pulpy mass; but this cannot be done unless a number of pebbles are swallowed with the food, which, by the working of the muscular walls, titurate the food among them. Hence, however plentiful the food of a granivorous bird may be, if sand, gravel, or pebbles be denied, it perishes for want in the midst of plenty. In carnivorous birds, there is no gizzard, but merely its indication in the existence of fine muscular fibres.

Thus has been sketched a discursive outline of the general mechanism and structure of birds,—their feathers, their flight, their receptacles for air, their bones, and organs of digestion have been presented to our reader's notice; briefly, it true, but still sufficiently to demonstrate the unerring wisdom and power of the great God of nature, of that God who, by stronger attractions than those of the most glorious exhibition of his power in these his lower works, by the cords of his love, has ever drawn his people, the ransomed of his choice, bought with the precious blood of his Son, to adore his unspeakable goodness—that goodness which is displayed so astonishingly in the works of nature, but still more in the works of grace. Surely we ought not to forget that he who regardeth the sparrow as it falls has numbered the“ very hairs of our heads." Let all his works then praise him, and chiefly man, for whose soul God has manifested his great care and love, even by sending his only begotten Son into the world to save sinners. Surely the believer in Christ is bound by the strongest obligations to trust in the goodness of his heavenly Father.

We shall now make a few remarks on the system of arrangement which science has adopted in classifying this beautiful portion of the Creator's works.

Diversified in their forms, as in their plumage, the feathered tribes offer, especially upon a superficial examination, a maze of intricacy apparently insuperable, and which, it must be allowed, requires both patience and attention to unravel; hence the necessity of a systematic arrangement, which, the more it is constructed upon the indications of nature, and the less it is influenced by theoretical speculations, will be, at the same time, the more simple and easy of remembrance. A systematic arrangement is not, however, to be considered as the ultimate end to which the student's aim is directed, but merely as a grammar for aiding further progress,

-a key to the door of the temple, the means and not the end. Since the days of Linnæus, who cleared the way as a pioneer for those who should come after him, succeeding naturalists have altered, modified, and improved the great outline which he had prepared. The natural affinities, which are to be traced throughout the different groups composing the class, indicating different degrees of relationship, constitute the basis upon which the system proceeds ; still, as few persons see exactly alike, so different authors, all of distinguished celebrity, have sketched out different modes of arrangement, according as they have severally interpreted the hieroglyphic characters of nature. Înto the merits or demerits of these arrangements we shall not presume to enter; several are very elaborate, and can only be comprehended in their full extent by professed naturalists; our object is only to prepare the way for deeper research, and to lead into the paths of science by the simplest road. In the primary divisions, then, we shall follow Cuvier, reserving the liberty of judgment in the adopotion or rejection of the subordinate sections; at the same time observing that, in so wide a field, we can only hope to present the reader with general and comprehensive views.

But before we present a sketch of the plan of the great divisions, we must first state the technical names in perpetual use, applied to the different parts of birds, without a knowledge of which the description of genera or species cannot be clearly understood. In botany there is an array of nomenclature oppressive in the extreme to the learner, but which he must, nevertheless, acquire. In ornithology, the contrary happily is the case ; still, in order to make ourselves clearly understood, we subjoin the following sketch.

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1. The Beak (rostrum) consisting of two horny mandibles, the upper being pierced by the nostrils, and having in some birds a membrane termed cere, covering its base;

in others, bristle-like hairs, projecting forwards, so as to cover the nostrils ; these bristles are termed vibrissæ.

2. The head (caput), its back part is termed the occiput. The space below the eye is the cheek, on which may be seen a tuft of feathers covering the ears, and therefore called

3. Ear coverts.
4. The back.

5. The spurious wing or winglet; it is composed of the feathers of the thumb.

6. The wing coverts (tectrices alæ). 7. The greater wing coverts (tectrices remigum). 8. The scapularies (scapulares). 9. The quill feathers (remiges primarii). 10. The secondaries (remiges secundarii). 11. The tail feathers, or tail (rectrices, or cauda). 12. Upper tail coverts, or rump (uropygium). 13. Under tail coverts (crissum). 14. Tarsus, and toes.

The remainder of the body bears the usual names, and requires no special notice.

As in the class Mammalia, so in that of Birds, the first great groups into which it is separated are termed Orders ; of these Ñ. Temminck makes sixteen; Mr. Vigors, in his sketches of the quinary arrangement, five namely, Raptores, Insessores, Rasores, Grallatores, and Natatores. The second order, or that of Insessores, comprehends all the perching birds which are not true birds of prey, and unites into one two orders of Cuvier ; namely, the Passeres (oiseaux passereaux) and the Zygodactyli or Scansores (oiseaux grimpeurs), so that the orders, as they stand in Cuvier's “ Regne Animal,are six. The following is their programmeTABLE OF THE ORDERS OF THE CLASS

AVES, OR BIRDS. 1.-THE RAPTORIAL ORDER. Raptores. Vig. Beak strong and hooked; talons sharp, incurved, and powerful ; body muscular ; appetite carnivorous ; stomach membranous, with only a slight tissue of muscular fibres.

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