Oldalképek
PDF
ePub

GoD it is, that makes all the creatures serve us, and takes care of our sleeps, and preserves all plants and elements, all minerals and vegetables, all beasts and birds, all fishes and insects, for food to us and for ornament, for physick and instruction, for variety and wonder, for delight and for religion.

JEREMY TAYLOR.

The fall of kings,

The rage of nations, and the crush of states,
Move not the man, who from the world escaped,
In still retreats, and flowery solitudes,

TO NATURE'S VOICE attends, from month to month,
And day to day, thro' the revolving year;
Admiring sees her in her every shape,
Feels all her sweet emotions at his heart,

Takes what she lib'ral gives, nor thinks of more.

THOMSON.

He that enlarges his curiosity after the WORKS oF NATURE, demonstrably multiplies the inlets to happiness; the young, therefore, should at once make use of the SPRING of the year, and the Spring of Life, to acquire, while their minds may be yet impressed with new images, a love of innocent pleasures, and an ardour for useful knowledge; and to remember that a blighted Spring makes a barren year, and that the Vernal Flowers, however beautiful and gay, are only intended by Nature as preparatives to Autumnal Fruits.

JOHNSON.

Introduction.

ELEMENTS

OF

BRITISH ORNITHOLOGY.

Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Matt. vi, 26.

BIRDS are unquestionably the most beautiful of the animated tribes; they embellish our forests and afford amusement in our walks; while their pleasures, their notes, and even their animosities, serve only to enliven the general face of Nature, and to cheer the contemplative mind. In no part of the animal creation are the wisdom, the goodness, and bounty of Providence displayed in a more lively manner than in the formation and various endowments of the feathered tribes; and whether we examine their elegance and symmetry, their beauty and delicacy of colour, their peculiar habits and economy, we shall have sufficient cause for adoring the wisdom of their benevolent CREATOR.

As birds are destined to move through the light medium of the air, they are far inferior both in weight and magnitude to quadrupeds: the largest bird, the ostrich, bears no proportion to the elephant; nor does the humming bird, which Nature has placed at the other extremity of this class, nearly approach to the size of a mouse. Nature, as she

approximates the confines of each class, confers more and more of the properties of the adjoining one on each species; till at last they so nearly unite, that it is often doubtful to what family an individual belongs. The ostrich, placed at the extremity of the birds, appears in many respects nearly allied to a superior class: being covered with hair, like feathers, and incapable of flight, it makes a near approach to the race of quadrupeds; while the small humming bird, of the size of a humble bee, and sucking, like it, the nectaries of flowers, seems to be degraded nearly to the rank of an insect.

To compensate their want of strength, birds are supplied with swiftness; and to avoid those enemies which they are not fitted to oppose, they are endowed with the faculty of ascending into the air. They appear, indeed, to be entirely formed for a life of escape, every part of their anatomy being calculated for swiftness; and, as they are designed to soar on high, all their parts are proportionably light. This leads us to consider more particularly the

Structure of Birds.

The skeleton or bony frame of birds is, in general, of a lighter nature than in quadrupeds; the spine is immoveable, but the neck lengthened and flexible: the breast-bone very large, with a prominent keel down the middle, and formed for the attachment of very strong muscles. The bones of the wings are similar to those of the fore legs in quadrupeds, but the termination is in three joints or fingers only, of which the exterior one is very short. What are commonly called the legs, are analogous to the hind legs in quadrupeds, and they terminate in general in four toes, three of which are commonly directed forwards, and one backwards; but in some

birds there are only two toes, in others, only three. All the bones in birds are much lighter, or with a larger cavity, than in quadrupeds.

The feathers with which birds are covered, resemble in their nature the hair of quadrupeds, being composed of a similar substance appearing in a different form. 6 Every single feather (says Dr. Paley) is a mechanical wonder. If we look at the quill, we find properties not easily brought together, -strength and lightness. I know few things more remarkable than the strength and lightness of the very. pen with which I am now writing. If we cast our eye toward the upper part of the stem, we see a material made for the purpose, used in no other class of animals, and in no other part of birds; tough, light, pliant, elastic. The pith, also, which feeds the feathers, is neither bone, flesh, membrane, nor, tendon.

But the most artificial part of a feather is the beard, or, as it is sometimes called, the vane; which we usually strip off from one side, or both, when we make a pen. The separate pieces of which this is composed are called threads, filaments, or rays. Now the first thing which an attentive observer will remark is, how much stronger the beard of the feather shows itself to be when pressed in a direction perpendicular to its plane, than when rubbed either up or down in the line of the stem; and he will soon discover, that the threads of which these beards are composed are flat, and placed with their flat sides towards each other; by which means, while they easily bend for the approaching of each other, as any one may perceive by drawing his finger ever so lightly upwards, they are much harder to bend out of their plane, which is the direction in which they have to encounter the impulse and pressure of the air, and in which their strength is wanted. It is also to be observed, that when two threads, sepab

[ocr errors]

rated by accident or force, are brought together again, they immediately reclasp. Draw your finger down the feather which is against the grain, and you break, probably, the junction of some of the contiguous threads; draw your finger up the feather, and you restore all things to their former state.

It is no common mechanism by which this contrivance is effected. The threads or laminæ above mentioned are interlaced with one another; and the interlacing is performed by means of a vast number of fibres or teeth which the threads shoot forth on each side, and which hook and grapple together.

[ocr errors]

Fifty of these fibres have been counted in one twentieth of an inch. They are crooked, but curved after a different manner; for those which proceed from the thread on the side toward the extremity of the feather are longer, more flexible, and bent downward; whereas those which proceed from the side toward the beginning or quill-end of the feather, are shorter, firmer, and turned upward. When two laminæ, therefore, are pressed together, the crooked parts of the long fibres fall into the cavity made by the crooked parts of the others; just as the latch which is fastened to a door enters into the cavity of the catch fixed to the door-post, and there hooking itself, fastens the door!'

Beneath, or under the common feathers or general plumage, the skin in birds is immediately covered with a much finer or softer feathery substance, called down. The throat, after passing down to a certain distance, dilates itself into a large membranaceous bag, answering to the stomach in quadrupeds: it is called the crop, and its great use is to soften the food taken into it, in order to prepare it for passing into another strong receptacle, called the gizzard. This, which may be considered as a more powerful stomach, consists of two very strong muscles, lined and covered with a strong tendinous

« ElőzőTovább »