and frequently only acquire their mature dress after the lapse of three or four years, the plumage undergoing a certain change at each moult. These circumstances undoubtedly throw great difficulties in the way of the student of ornithology, and it is perhaps not much to be wondered at, if we have sometimes half a dozen different names for different states of the same species; but it must also be confessed, that in this, as in other departments of natural history, the desire to describe new species has often led to an unjustifiable multiplication of errors of this description.

In a zoological point of view the greatest importance attaches to the feathers of the wings and tail, to which different names have been given. The quills are inserted into all the bones of the wing, but the longest are those attached to the bones of the hand, and to these the name of primaries is given. The feathers supported by the fore-arm are denominated secondaries, and those

attached to the humerus tertiaries. The thumb also bears a few quills, which form what is called the alula, or bastard wing. These, and some other feathers to which particular names have been given, are shown in the annexed engraving. The base of the quills is covered by a series of large feathers called the wing coverts, which are also distinguished into primary and secondary. The feathers of the tail are furnished with numerous muscles, by which they can be spread out and folded up like a fan. Their bases are also covered both above and beneath by smaller feathers, which are called the tail coverts.

It is impossible to conceive any covering more beautifully adapted to the peculiar wants of these creatures than that with which they are endowed by nature. All the feathers being directed backward, the most rapid motion through the air only tends to press them more closely to the body, and the warm air, confined among the inner downy fibers, is thus effectually prevented from escaping. In the aquatic birds the feathers are constantly lubricated by an oily secretion, which completely excludes the water. In the wings the quill-feathers exhibit in the highest degree a union of the two qualities of lightness and strength, while by their arrange

ment they can be folded together into a very small compass.

In their reproduction birds are strictly oviparous. The eggs are always inclosed in a hard shell, consisting of calcareous matter, and, unlike the animals of some of the succeeding classes, birds, instead of abandoning the hatching of their eggs and the development of their offspring to chance, almost invariably devote their whole attention, during the breeding season, to this important object, sitting constantly upon the eggs to communicate to them the degree of warmth necessary for the evolution of the embryo, and attending to the wants of their newly-hatched young, until the latter are in a condition to shift for themselves.

Most birds live in pairs during the breeding season, which usually occurs only once in the year; in many cases the conjugal union is for life. Both sexes generally take an equal part in the care of the young. They usually form a nest of some description for the reception of the eggs; this is composed of the most diverse materials, such as sticks, moss, wool, vegetable fibers, &c.; in many instances the work of these little architects must excite the admiration of every observer. The nests of different individuals of the same species are generally not only of the same form, but even composed nearly of the same materials, so that a person, accustomed to the inspection of

THE GOLDEN ORIOLE: ILLUSTRATION OF PAIRING AND NEST-BUILDING.

birds' nests, can generally tell at a glance the species to which a particular nest belongs. The number of eggs laid is also very uniform in each species.

In the structure and development of the egg, we find a great uniformity throughout this class, the development of the embryo taking place here in precisely the same manner as in the reptiles. But notwithstanding this general uniformity in the processes of reproduction, there is a remarkable difference in the condition of the young birds at the moment of hatching, and this has given rise to the division of the class into two great sections. In some, which usually reside upon the ground, where they form their nests and hatch their young, the latter are able to run about from the moment of their breaking the egg-shell, and the only care of the parents is devoted to protecting their offspring from danger, and leading them into those places where they are likely to meet with food. The others, which in fact constitute the majority of the class, pass more of their time in the air, and generally repose upon the trees, or in other elevated situations, where they also build their nests, and the young birds for some time after they are hatched, remain in the nest in a comparatively helpless state, their parents bringing them food, and attending upon them most assiduously until their feathers are sufficiently grown to enable them to support themselves upon the wing. A chicken or a partridge, a day after it is hatched, will run about and pick up seeds, separating them from the gravel among which they lie, while the young of the tree-birds remain often a month in the nest, receiving without discrimination what is given by their parents. This difference between the young of the two classes will be more apparent by a glance at the engravings pages 7 and 8. The first represents a young curlew, a day or two old, going forth with all his faculties awake, and almost ready to make his way in the world; the other

presents a barn-owl, which has reached the comparative old age of a month, and yet-though it may possess something of the serious and knowing aspect of the Bird of Wisdom-seems still sadly puzzled to know which foot he ought to put first.

The longevity of birds is various, and, differing from the case of men and quadrupeds, seems to bear little proportion to the age at which they acquire maturity. A few months, or even a few weeks, are sufficient to bring them to their perfection of stature, instincts, and powers. Land animals generally live five or six times as long as the period of their growth, that is, the time required for reaching their maturity; while birds live ten times as long as the period of their growth. Domestic fowls, pigeons, and canaries live to the age of twenty years; parrots thirty, geese fifty, pelicans eighty; swans, ravens, and eagles exceed a century.

The velocity with which birds are able to travel in their aerial element has no parallel among terrestrial animals. The swiftest horse may run a mile in something less than two minutes, but this speed can only be sustained for a very brief period, while birds in their migrations move at the rate of a mile a minute for several successive hours. Many of them, no doubt, actually travel six to eight hundred miles a day, and are thus able to go from the arctic to the torrid zones in three or four days. A falcon, sent to the Duke of Lerma from Teneriffe to Andalusia, returned in sixteen hours, a distance of seven hundred and eighty miles. The gulls of Barbadoes go to the distance of two hundred miles in search of their food, making a daily flight of four hundred miles. The migrations of birds are among the most curious and wonderful phenomena connected with their natural history. In some cases these are of comparatively small extent, being prompted only by the necessity of obtaining a supply of food; but many species, known as Birds of Passage, perform long journeys twice in the year, visiting temperate or even cold climates during the summer, and quitting them on the approach of winter for more genial climes. The great object of this movement in the economy of nature is to rear their young in the solitude or security of the colder zones, away from the destructive animals-serpents, monkeys, cats, and other predaceous beasts—which infest the tropics. As these birds have neither reason nor experience, they are endowed with instincts which guide them in their wanderings, often extending across seas

and rivers and continents for thousands of miles. The various modes in which these migrations are performed by different species are exceedingly curious. Some of them, as owls, butcherbirds, kingfishers, thrushes, fly-catchers, night-hawks, whippoorwills, &c., fly only at night, and others, as crows, wrens, pies, creepers, cross-bills, larks, bluebirds, swallows, &c., only in the day. Many move near the earth, while others soar beyond the reach of vision; some go noiseless as the shadows; others proceed with all the noisy parade of a military march. Some-as our bluebird, robin, blackbird, meadow-lark, cedar-bird, pewee, &c.—do not generally pass beyond the boundaries of our North American continent; they go only so far as may be necessary to find food, and consequently are the first to return with spring; others—as the herons, plovers, swans, cranes, wild geese, &c.—are so impelled by the migratory instinct that they stop neither day nor night till they have reached their far southern homes. While most proceed wholly on their wings, there are some, as the coots and rails, that make a part of their long journey on foot, and others, as the guillemots, divers, and penguins, that make their voyage chiefly by dint of swimming! The young loons, bred in inland lakes and ponds, without the use of their wings, pursue their route by floundering from pond to pond at night until they reach some creek connected with the sea; upon this they fearlessly launch themselves, and finally work their way through storm and calm to the milder zone which they seek. These migrations, it may be observed, are chiefly confined to birds that are bred in temperate climates; but it appears that those which are natives of warm regions have a similar movement, though of less extent.

In considering the senses of birds, we shall observe that Smell is generally less acute in them

than in quadrupeds. The nasal cavity exhibits but few convolutions, and in some birds the external nasal apertures are either entirely wanting or reduced to a very small size. The auditory apparatus is well developed, and the Hearing is very perfect, though there is no external ear. The sense of Taste is enjoyed in a very inferior degree; the Sight surpasses in power any thing with which we are acquainted in other animals. The eyes are large, but have little power of motion; in some birds, as the owls, they are immovable in their sockets. They are furnished with two movable eyelids and a nictating membrane, which performs the process of winking, thus shielding and clearing the eyes without closing the sight. The eye is adapted alike to near and distant vision, so that a bird a thousand feet in the air is able to see, on the earth beneath, the small quadrupeds or reptiles or insects, or even the grain on which it is to feed. By its gift of vision the bird is able to discover at a glance its way amid the mazes of the forest, and to distinguish birds, reptiles, and insects whose colors blend with the objects of nature around and conceal them from the sight of man.

There is nothing, perhaps, more remarkable in this interesting class of animated beings than the voice. The windpipe is wider and stronger in birds than in any other animals, and usually terminates in a large cavity, which augments the sound. The lungs, too, have greater extent, and as we have stated, communicate with internal cavities which are capable of being expanded with air—thus, besides lightening the body, giving additional force to the voice. The scream of the eagle seventeen thousand feet in the air, and thus more than three miles distant, may be distinctly heard, and the calls of flocks of storks and geese, beyond the reach of sight and equally remote, are often audible. And these wonderful powers of voice are infinitely diversified in their expression and use, from the simplest call to the most complicated and elaborate song. Every species of bird has a peculiarity of voice possessed by no other. By this variety of vocal endowment they are enabled to express to one another their wants and passions. This power of communication exists not only between the sexes, but between all individuals of the same species. The least experienced observer of nature knows, too, that the approach of danger is expressed by a universally intelligible cry, which, if uttered by the wren, for instance, is understood by the turkey-cock, and vice versa. Of whatever species the one may be which first perceives the approach of a bird of prey, it is able to excite the attention of all birds in the neighborhood by its peculiar cry of warning. As soon as the blue-tit utters her Iss! so indicative of fear and terror—which, nevertheless, she seems sometimes to do from pure love of mischief-the wood is silent in an instant, and every bird either listens for the enemy's coming, or hastens to the aid of the comrade who is attacked. This peculiarity is so marked, that in Europe the fowlers have not failed to turn it to purposes of profit. They build a hut, thatch it with green boughs, and cover the roof with a plentiful supply of limed twigs. They then display a screech-owl or other bird of prey, imitate the sonorous cry of a jay or woodpecker in fear and distress, and birds of every size and species flock to the hut and are caught.

The tones of happiness and joy, by which one bird is able to call forth from another a similar expression of feeling, seem to be almost as universally intelligible. Nor is this joy shown by song alone, although when one little creature begins to sing, the whole wood, or, among domesticated birds, the whole room, soon manifests its sympathy by a general chorus. The same is frequently indicated by single notes. In spring and autumn a great variety of species may often be noticed in hedges and bushes, which seem to take great delight in the utterance of a common cry. Again, when in confinement, birds may often be induced to sing by various noises, loud conversation, and above all, by instrumental music, though on wild birds these means would produce no other effect than to frighten them away.

In

n many cases, also, different species have a language, which serves for various purposes of mutual communication. For instance, ravens, crows, jackdaws, &c., understand and respond, both by voice and action, to each other's call. By imitating the call of the yellow-hammer, the birdcatchers of Europe succeed in taking the ortolan, the snow-bunting, the reed-bunting, the foolish bunting, &c.; the cry of the chaffinch decoys the mountain-finch, and that of the siskin attracts the citron-finch and the redpole.

"Every bird," says Bechstein, "has received from nature the power of uttering either a song or VOL. II.-2