the dorsal and anal fins lend good help. Thus, the pectoral, the dorsal, the anal, and the caudal fins, all act together, and in complete unison, in speeding the fish through the water. But, the superior importance of the caudal fin as a propeller is seen in this when a fish is deprived of its caudal fin, it ceases to move forward, and allows itself to be tossed about at the mercy of the stream, or the waves. The pectoral fins, therefore, are not, like the wings of a bird, the fish's only locomotive power, nor, in fish that have belly fins (fish that live near the bottom-such as the fluke and the flounder-have no belly fins), are they its sole supporters, as the use of the belly fins is to assist in sustaining the fish, and, along with the pectoral fins, enable it to preserve its equilibrium in the water. The shape also of most fish is admirably adapted for rapid motion in an element like water. Gradually tapering from the middle towards both head and tail, its fore part offers but small resistance to the water; and yet, as the maximum of resistance is in the fore part, the hinder part is left almost free to perform its twofold office of propeller and rudder. As the action or working of an oar at the stern of a boat both moves the vessel forward and directs its course; so, the tail of a fish, by moving first in one direction and then in the opposite, impels the fish at once onward and toward the point at which it aims. Some fish are cold-blooded, and breathe by means of gills; others are warm-blooded, and breathe by lungs, like land animals

one of those circumstances which serve to connect the land and the water animals in the scale of being. Those which breathe by gills have the power of decomposing the water, and in that way supply themselves with appropriate breath; those that possess lungs breathe the same element of air as we do; and when, from accidental circumstances, they continue too long immersed in water, they drown almost as readily

as animals bred on land. Some fish feed upon seaweeds and animalcula engendered in the waters; also on insects that fly near the surface of bodies of water. Many of the larger sorts prey upon the smaller, and, in this way, prevent the waters from becoming overstocked with inhabitants; others, again, besides acting as the scavengers of the deep, and devouring a variety of substances in a state of putrefaction, make food of both man and land animals of every sort-living and dead-when they fall in their way.

THE CREATION AND ADAPTATION OF BIRDS.

There is more of sameness in the ways in which fish spend their lives, than in the modes and habits of birds. Differences in the elements in which they respectively dwell, and their special adaptations to suit these different elements, lead to corresponding varieties in their modes of living. All fish have their habitat permanently in water, and derive their chief sustenance from things which the waters bring forth. Some birds dwell constantly on land, and find food in the various products of the fields; others pass much of their time on or beside rivers, pools, marshes, lakes, seas, &c., and live upon fish and other things bred in the waters; others, shunning the produce alike of the fields and of the waters, mount into the air in search of insects as food; many feed on worms and other creeping things; birds of prey soar high in air in quest of other birds, small land animals, and carrion, which their exquisite smell enables them to discover; others, again, seem never to have been intended "to fly above the earth in the open firmament of heaven," but made to spend their life on the ground, and there seek their humble means of support.

Birds have very light bones through which air cir

culates, small heads, and the fore part of their body inferior in bulk and weight to the hinder, and in the latter part they are furnished with air-sacs. Such a configuration well adapts them for rapid motion, whether on the ground, or in high and long journeys through the air. The feathers of birds, like the hair and wool of quadrupeds, serve them as clothing, and, moreover, contribute to their lightness when on the wing. There is one peculiar adaptation connected with birds, that I do not remember of having ever seen noticed; they breathe at great heights apparently with as much ease, freedom, and enjoyment, as when on or near the surface of the earth; and their thick warm clothing of feathers protects them from all inconveniences arising from the cold which prevails in the upper regions of the atmosphere; just as the same means shields from cold those that swim and dive in water. Man has been gifted with a physical constitution, which enables him to live in more climates, and subsist on greater varieties of food, than any other inhabitant of the globe, yet man does not breathe freely, and with safety, in too high regions, and in too rarefied an atmosphere. The peculiar adaptations of birds to fit them for their respective modes of life, are among the most obvious adjustments in the animal kingdom.

In giving a sketch of the various classes of birds, with the view of pointing out their respective and peculiar adaptations, I shall follow the division of the celebrated Cuvier.

I. SWIMMERS: birds fitted, by their bodily constitution and special instincts, to pass much of their time on water, and feed on such substances-animal and vegetable as are engendered there. Birds of this class have their feathers set very close, and lined inwardly, with a very thick down-properties, which serve to keep their bodies both dry and warm, and also to ren

der efforts to bear themselves up in the water altogether unnecessary. When they swim their feet act as paddles or propellers, and, the more effectually to answer that end, they are webbed. In order to enable them to seize their prey with more convenience when afloat, their necks are longer than their legs-a peculiarity of formation, in which they differ from other birds. A few of them, in their long aquatic excursions, occasionally use their wings as propellers-beating the air, as birds that fly; others, that cannot employ these appendages above water, work them as fins in diving below. To this class belong the duck, the goose, the swan, the gull, the pelican, the awk, the penguin, the grebe, the frigate bird, the albatross, the merganser, &c. Linnæus calls them the Duck kind.

II. WADERS: birds whose whole nature adapts and inclines them to wade in the shallow parts of marshes, pools, lakes, and other bodies of water, in search of food, such as small fish, animalcula, &c., bred in the waters-whether salt or fresh, and which with worms and other small land animals constitute their whole food. They have very long legs-a provision which enables them to wade to those parts of the water where their prey is generally found; their bill is sharp, their necks in general long-adaptations well fitted to promote their peculiar mode of life. As they could not conveniently double their legs in flight, like other birds, they stretch them out behind, where they act as rudders; hence they require but a short tail. The crane, the stork, the bittern, the plover, the snipe, the bustard, the heron, the ibis, the flamingo, &c., belong to this class. Linnæus names them the Crane kind.

III. RUNNERS: birds which, though most of them have wings, or the rudiments of wings, are formed rather for running than for mounting into the air. The short wings of some of this class terminate in a spur or

claw-an appendage intended, it may be, to make the wings a more formidable weapon of defence. The ostrich, the bustard, the cassowary, the emu, the dodo (now extinct), &c., belong to this class. Some of them, such as the ostrich, use their wings as sails when running; whilst others, as the bustard, take short flights when pursued, but the effort soon tires them, and so they are easily taken.

IV. SCRATCHERS: birds which scratch the ground with their feet in search of food. Domestic poultry, the pigeon, the turkey, the peacock, the partridge, the pheasant, the guinea-fowl, &c., are instances of this kind. Though the generic name given to this class be none of the most elegant, in their utility to mankind they are superior to all other birds taken together. The flesh of the most of them is sweet, savoury, delicate, and nutritious; and the eggs, more especially those of the domestic hen and duck, supply a large abundance of rich and choice food wherever they are reared. The Creator, in bestowing their peculiar properties on this class of birds, seems to have had particularly in view to make ample provision for the wants and comforts of yet uncreated man.

V. CLIMBERS: birds fitted to climb trees in search of food, and also as a refuge against such enemies as are incapable of following them. They are furnished with two toes before and two behind, a provision which enables them to ascend trees, and other heights, with both ease and security. The most noted of the climbers are-the cuckoo, the woodpecker, the wry-neck, the toucan, and all the varieties of the parrots, parroquets, &c.

VI. PERCHERS: birds which roost or perch on trees, roofs, and other convenient places; those have three toes before and one behind, all adapted for catching, not for climbing. Familiar instances are-the sparrow, the linnet, the crow, the magpie, the starling,