clear running waters, and is well known for its use in bleeding. The leech's head is armed with a sharp instrument that makes three wounds at once. It consists of three sharp tubercles, strong enough to cut through the skin of a man, or even of an ox or horse. The mouth is as it were the body of the pump, and the tongue or fleshy nipple the sucker; by the working of this piece of mechanism, the blood is made to rise up to the conduit which conveys it to the animal's stomach, which is a membranaceous skin divided into twenty-four small cells. The blood which is sucked out is there preserved for several months almost without coagulating, and proves a store of provision to the animal. The nutritious parts, pure and already digested by animals, require not to be disengaged from the heterogeneous substances nor indeed is there any thing like an anus discoverable in the leech; mere transpiration seems to be all that it performs, the matter fixing on the surface of its body, and afterwards coming off in small threads. Of this an experiment may be tried by putting a leech into oil, where it keeps alive for several days; upon being taken out and put into water, there appears to loosen from its body, a kind of slough shaped like the creature's body. The organ of respiration seems to be situated in the mouth; for if, like an insect, it drew its breath through vent holes, it would not subsist in oil, as by it they would be stopped up. This is the only species that is used in medicine; being applied to the skin to draw off blood. If the leech does not fasten, a drop of sugared milk is put on the spot it is wished to fix on, or a little blood is drawn by means of a slight puncture, after which it immediately settles. The leech when fixed should be watched, lest it should find its way into the anus when used for the hemorrhoids, or penetrate into the œsophagus if employed to draw the gums; otherwise it would make great havock in the stomach or intestines. In such a case, the best and quickest remedy is to swallow some salt; the application of which makes it quit its hold when it sucks longer than is intended. Salt of tartar, volatile alkali, pepper, and acids, make it also leave the part on which it was applied. Cows and horses have been known to receive them in drinking into the throat. The usual remedy is to force down some salt, which makes them fall off. If, on the contrary, it is intended that the leech should draw a larger quantity of blood, the end of its tail is cut off; and it then sucks continually to make up the loss it sustains. The discharge occasioned by the puncture of a leech is usually of more service than the process itself. When too abundant, it is easily stopped with brandy, vinegar, or other styptics, or with a compress of dry linen rag bound strongly on the bleeding orifice.

H. muricata, the muricated leech, has a taper body, rounded at the greater extremity, and furnished with two small tentacula, or horns, strongly annulated and rugged upon the rings, the tail dilated. It inhabits the Atlantic Ocean, and is by the fishermen called the sea-leech. It adheres to fish, and generally leaves a black mark on the spot.

H. sangui-suga, the horse-leech, is of a larger

size than the medicinal leech. Its skin is smooth and glossy; the body is depressed; the back is dusky; and the belly is of a yellowish-green, having a yellow lateral margin. It inhabits stagnant waters. At Ceylon, travellers who walk bare-legged are molested by the great numbers of leeches concealed under the grass. All leeches vary in their color at some seasons, but they are generally of a dusky greenish-brown or yellow, and often variegated. They are very restless before a change of weather, if confined in glasses. They suck blood with greater avidity than the medicinal, and are dangerous to apply to the skin for that reason.

HIRUNDO, in ornithology, a genus of birds of the order of passeres. There are numerous species, chiefly distinguished by their color. The most remarkable are the following:

1. H. ambrosiaca, the ambergris swallow. It is about the size of a wren, with a gray plumage and a very forked tail; the bill is blackish, and the legs are brown. It inhabits Senegal, and is said to smell very strong of ambergris.

Its

1. H. apus, the swift, is a large species, being nearly eight inches long, with an extent of wing nearly eighteen inches, though the weight of the bird is only one ounce. Their feet are so small, that the action of walking and rising from the ground is extremely difficult, but they have full compensation, being furnished with ample means for an easy and continual flight. It is more on the wing than any other swallow; its flight is more rapid, and that attended with a shrill scream. It rests by clinging against some wall, or other apt body: whence Klein styles this species hirundo muraria. It breeds under the eaves of houses, in steeples, and other lofty buildings; and makes its nest of grasses and feathers. feet are of a particular structure, all the toes standing forward: the least consists of only one bone; the others of an equal number, viz. two each; in which they differ from those of all other birds; a construction, however, nicely adapted to the purposes in which their feet are employed. The swift is a summer inhabitant of these kingdoms. It comes the latest, and departs the soonest, of any of the tribe; not always staying till the middle of August, and often not arriving before the beginning of May. A pair of these birds were found adhering by their claws, and in a torpid state, in February 1766, under the roof of Longnor Chapel, in Shropshire; on being brought to a fire, they revived, and moved about in the room. The materials of its nest it collects either as they are carried about by the winds, or picks them up from the surface in its sweeping flight. Its food is undeniably the insects that fill the air. Its drink is taken in transient sips from the water's surface. Even its amorous rites are performed on high. The swift is a most alert bird, rising very early and retiring to roost very late; and is on the wing in the height of summer at least sixteen hours. In the longest days it does not withdraw to rest till nine in the evening, being the latest of all day birds. Just before they retire whole groups of them assemble high in the air, and squeak, and shoot about with wonderful rapidity. But this bird is never so much alive as in sultry thundery

weather, when it expresses great alacrity, and calls forth all its powers. When the hen has sat hard all day, she rushes forth just as it is almost dark, and stretches and relieves her weary limbs, and snatches a scanty meal for a few minutes, and then returns to her duty of incubation. Swifts, when wantonly shot while they have young, discover a little lump of insects in their mouths, which they pouch and hold under their tongue. In general, as already observed, they feed in a much higher district than the other species; they also range to vast distances; since locomotion is no labor to them, who are endowed with such wonderful powers of wing. At certain times in the summer, however, they have been observed hawking very low for hours together over pools and streams; and, upon enquiring into the object of their pursuit that induced them to descend so much below their usual range, it has been found that they were taking phryganeæ, ephemera, and libellula (cadew-flies, may-flies, and dragon-flies), that were just emerged out of their aurelia state. They are out all day long, even though wet, feeding, and disregarding the rain. But windy weather, and particularly with heavy showers, they dislike; and on such days withdraw, and are scarcely ever seen. There is a circumstance respecting the color of swifts,' Mr. White remarks, which seems not to be unworthy our attention. When they arrive in the spring, they are all over of a glossy dark soot color, except their chins, which are white; but, by being all day long in the sun and air, they become quite weather-beaten and bleached before they depart, and yet they return glossy again in the spring. Now if they pursue the sun into lower latitudes, as some suppose, in order to enjoy a perpetual summer, why do they not return bleached? Do they not rather perhaps retire to rest for a season, and at that juncture moult and change their feathers, since all other birds are known to moult soon after the season of breeding? Swifts are very anomalous in many particulars, dissenting from all their congeners not only in the number of their young, but in breeding once in a summer; whereas all the other British hirundines breed invariably twice. They retire, as to the main body of them, by the 10th of August, and sometimes a few days sooner; and every straggler invariably withdraws by the 20th, while their congeners, all of them, stay till the beginning of October; many through all that month, and some occasionally to the beginning of November. This early retreat is mysterious and wonderful, since that time is often the sweetest season in the year. But, what is more extraordinary, they begin to retire still earlier in the most southerly parts of Andalusia, where they can be no ways influenced by any defect of heat; or, as one might suppose, defect of food. Are they regulated in their motions with us by a failure of food, or by a propensity to moulting, or by a disposition to rest after so rapid a life, or by what? This is one of those incidents in natural history, that not only baffles our searches, but almost eludes our guesses. Swifts never perch on trees or roofs, and so never congregate with their congeners. They are fearless while haunt

ing their nesting places, and are not to be scared with a gun; and are often beaten down with poles and cudgels as they stoop to go under the eaves. Swifts are much infested with those pests to the genus called hippoboscæ hirundinis; and often wriggle and scratch themselves in their flight, to get rid of that clinging annoyance. And young ones, overrun with these insects, are sometimes found under their nests, fallen to the ground; the number of vermin rendering their abode insupportable. The Swedes have bestowed a very pertinent name on this swallow, calling it ring-swala, from the perpetual rings or circles that it takes round the scene of its nidification. As these birds are apt to catch at every thing on the wing, many have taken them by a bait on a cock-chafer tied to a thread, which they have swallowed as freely as a fish theirs. In the Isle of Zant the boys are said to get on an elevated place, and, merely with a hook baited with a feather, have caught five or six dozen of them in a day. Besides our island, the swift is known to inhabit the whole of the European continent; and has also been noticed at the Cape of Good Hope, and Carolina in North America. Hence, most likely, it is a general inhabitant of both the old and new continents.

3. H. borbonica, the wheat swallow, is about the size of the swift: the plumage above is blackish brown; beneath gray, marked with longitudinal brown spots: the tail is even at the end: the bill and legs are black. This species inhabits the Isle of France; frequenting places sown with wheat, and glades of woods; affecting elevated situations, and frequently seen perched on trees and stones. It follows herds of cattle for the sake of the flies that surround them; and is frequently seen in the wake of ships in great numbers, in the road near the isle, for the same purpose. It is often observed in the evenings about the clefts in the mountains, where it is said to pass the night, and where it makes its nest; which is composed of straw and feathers. It lays two eggs, of a gray color, dotted with brown.

4. H. Cayennensis, the white-colored swallow, is about the size of the martin: the head and bill are black; the chin and throat white, passing from the last in a narrow collar round the neck; between the bill and eye is a streak of white, which forks off into two, one passing a little above, and the other a little way beneath the eye; the rest of the plumage is black, with a gloss of violet; but the greater coverts, nearest the body, are brown edged with white: the quills and tail are black, the last forked; the legs are black, and all the four toes placed before, as in the swift, and covered with feathers to the claws. This bird makes its nest in the houses at Cayenne. It is of a large size, in shape of a truncated cone; five inches one way by three the other, and nine inches in length. It is composed of the down of dog's bane, well woven together; the cavity divided obliquely about the middle, lengthways, by a partition, which spreads over that part of the nest where the eggs lie, which is pretty near the base: a small parcel of the same soft down, forming a kind of plug, is placed over the top, serving to keep the young

brood from the impression of the air; whence we may suppose them to be very tender.

6. H. esculenta, the edible swallow, is of a blackish-gray color, inclining a little to green; but on the back to the tail, as well as on the belly, this blackish color gradually changes into a mouse color. The whole length of the bird, from the bill to the tail, is about four inches and a half, and its height from the bill to the extremity of the middle toe three and a quarter. The distance from the tip of the one wing to that of the other, when extended, is ten and a quarter. The largest feathers of the wing are about four inches in length. The head is flat; but, on account of the thickness of the feathers, appears round, and to be of a large size in proportion to the rest of the body. The bill is broad, and ends in a sharp extremity, bent downwards, in the form of an awl. The width of it is increased by a naked piece of skin, somewhat like parchment, which, when the bill is shut, lies folded together; but which, when the bill opens, is considerably extended, and enables the bird to catch with greater ease, while on wing, the insects which serve it for food. The eyes are black, and of a considerable size. The tongue, which is not forked, is shaped like an arrow. The ears are flat, round, naked spots, with small oblong openings, and are entirely concealed under the feathers of the head. The neck is very short, as well as the legs and bones of the wings. The thighs are wholly covered with feathers, and the very tender lower parts of the legs, and the feet themselves, are covered with a skin like black parchment. Each foot has four toes, three of which are before, and one turned backwards. They are all detached from each other to the roots; and the middle one, together with the claw, is fully as long as the lower part of the leg. Each toe is furnished with a black, sharp, crooked claw, of a considerable length, by which the animal can, with great facility, attach himself to crags and rocks. The tail is fully as long as the body together with the neck and the head. When extended it is in the form of a wedge, and consists of ten large feathers. The first four on each side are long; and, when the tail is closed, extend almost an inch beyond the rest. The other feathers decrease towards the middle of the tail, and are equal to about the length of the body. But the most curious part of the natural history of this bird consists in the nest, which is composed of such materials as render it not only edible, but one of the greatest dainties of the Asiatic epicures. These nests are found in vast numbers in certain caverns, in various isles in the Sooloo Archipelago, situated between long. 117° and 120°, and lat. 5° and 7°, particularly in three small isles, or rather rocks; in the caverns of which the nests are found fixed to the stones in astonishing numbers. They are also found in amazing quantities on a small island called Toc, in the straits of Sunda, the caverns of which are lined with the nests; but no where in greater abundance than about Croee, near the south end of Sumatra, four miles up a river of that name. But they are not peculiar to the above places; for they are likewise common from Java to Cochinchina on the north, and from

the point of Sumatra west, to New Guinea on the east, where the sea is said to be covered with a viscous substance like half-melted glue, which the bird is supposed either to take up from the surface with its bill during flight, or to pick from the rocks when left there by the waves Of these nests, it is said, the Dutch alone export from Batavia 1000 pickles, upwards of 1300lbs. English weight, every year, which are brought from the Isles of Cochinchina, and those lying to the east of them. It is surprising that, among other luxuries imported from the east, these nests should not have found a way to our tables; being yet so scarce in England as to be kept as rarities in the cabinets of collectors. The bird. itself at Sumatra is called layonglayong. H. melba, the white-bellied swift, is in length eight inches and a half, and weighs 2 oz. 4 dr. ; the bill is half an inch long, somewhat bent, and black: the upper parts of the body are of a gray brown; the wings and tail deepest, with a gloss of red and green in some lights: the throat, breast, and belly, are white; on the neck is a collar of gray brown, mixed with black: the sides are dusky, and white mixed; lower part of the belly and under tail-coverts the same as the back the legs are flesh-colored, and covered with feathers on the fore part and inside: all the toes are placed forward, as in our swift. bird inhabits the mountainous parts of Spain; building in the holes of rocks. It is found also on the borders of the Rhone, in Savoy, the isle of Malta, Alps of Switzerland, and rock of Gibraltar. It comes into Savoy the beginning of April, and frequents the ponds and marshes for fifteen or twenty days; after which it retires to the mountainous parts to breed. It flies higher than our swift; but feeds on the same food, and its flesh is accounted a delicate morsel. This species is not numerous. Scopoli says it builds on the summit of the mountains of Tyrol.

This

H. nigra, the black swallow, measures nearly six inches in length: the color of the bird is wholly black, and the tail is forked. It inhabits St. Domingo and Cayenne; but it is not numerous. It is often seen to perch on dead trees: and only inhabits dry savannahs inland. scoops out a hole in the earth, half a foot long, with the mouth, very small, so as just to permit entrance: in this cavity it constructs the nest and rears its young.

H.

It

purpurea, the purple swallow, is in length. seven inches,and the whole body is of a deep violet, very glossy: the quills and tail are of the same color, but still deeper, and the last forked: the legs and claws are blackish, and the bill is black. The color of the female is dusky brown, with a slight tinge of violet. This species is found in summer in Carolina and Virginia: coming in May, and retiring at the approach of winter. The people are very fond of them, and make little conveniencies of boards on the outsides of their houses for the birds to build in, as is done for sparrows in England; being desirous to keep them near, as they are of much use in alarming the poultry of the approach of the hawk and other birds of prey; not only shrieking violently on the appearance of these enemies, but attack

ing them with all the efforts of our martins in Europe.

H. riparia, the sand martin, or shore bird, is four inches and three-quarters in length, with the whole upper parts of the body of a mouse-color, the throat and under parts white, the bill and legs blackish. It is common about the banks of rivers and sand-pits, where it terebrates a round and regular hole in the sand or earth, which is serpentine, horizontal, and about two feet deep. At the inner end of this burrow does the bird deposit, in a good degree of safety, her rude nest, consisting of fine grasses and feathers, usually goose-feathers,very inartificially laid together. "Though at first,' says Mr. White, one would be disinclined to believe that this weak bird, with her soft and tender bill and claws, should ever be able to bore the stubborn sand-bank without entirely disabling herself; yet with these feeble instruments have I seen a pair of them make great despatch; and could remark how much they had scooped that day by the fresh sand which ran down the bank, and was of a different color from that which lay loose and bleached in the sun. In what space of time these little artists are able to mine and finish these cavities, I have never been able to discover; but it would be a matter worthy of observation, where it falls in the way of any naturalist to make his remarks. One thing is remarkable-that, after some years, the old holes are forsaken and new ones bored; perhaps because the old habitations grow foul and fetid from long use, or because they may so abound with fleas as to become untenantable. This species of swallow is strangely annoyed with fleas; and we have seen fleas, bed fleas (pulex irritans), swarming at the mouths of these holes, like bees on the stools of their hives. The sand martin arrives much about the same time with the swallow; and lays, as she does, from four to six white eggs. But as this species is cryptogame, carrying on the busines of nidification, incubation, and the support of its young in the dark, it would not be easy to ascertain the time of breeding, were it not for the coming forth of the broods, which appear much about the time, or rather somewhat earlier than those of the swallow. The nestlings are supported in common like those of their congeners, with gnats and other small insects; and sometimes they are fed with libellula (dragon flies) almost as long as themselves. This hirundo is said to lay only once in a year, and to produce its young more early than the rest of its tribe: though, from this last circumstance, it would seem probable that they breed at least a second time, like the houseinartin and swallow. It does not always take pains to make a hole for a nest; frequently laying in cavities of quarries, and in hollows of trees, where it is convenient. When they happen to breed near hedges and inclosures they are often dispossessed of their breeding-holes by the house sparrow, which is on the same account a fell adversary to house martins. These hirundines are no songsters, but rather mute, making only a little harsh noise when a person approaches their nests. They seem not to be of a sociable turn, never with us congregating with their congeners in the autumn. They have a

peculiar manner of flying, fitting about with odd jerks and vacillations, not unlike the motions of a butterfly. Doubtless the flight of all hirundines is influenced by, and adapted to, the peculiar sort of insects which furnish their food.

H. rustica, the common or chimney swallow, is distinguished from all the other species by the superior forkiness of its tail, and by the red spot on the forehead and under the chin. The crown of the head, the whole upper part of the body, and the coverts of the wings, are black, glossed with a rich purplish blue, and most resplendent in the male: the breast and belly white, and in the male tinged with red: the tail is black; the two middle feathers are plain, the others marked transversely near the ends with a white spot: the exterior feathers of the tail are much longer in the male than in the female. The food is the same with that of all the genus; viz. insects. For taking these, in their swiftest flight, their parts are admirably contrived; their mouths are very wide to take in flies, &c., in their quickest motions; their wings are long, and adapted for distant and continual flight: and their tails are forked, to enable them to turn the readier in pursuit of their prey. This species is the first comer of all the British hirundines; and appears in general on or about the 13th of April, though now and then a straggler is seen much earlier. This species, though called the chimney swallow, by no means builds altogether in chimneys, but often in barns and out-houses against the rafters; as Virgil long ago remarked, (Georg. lib. iv. 306). In Sweden she builds in barns, and is called ladw swala, the barn swallow. In the warmer parts of Europe, where there are no chimneys to houses except they are English built, she constructs her nest in porches, gateways, galleries, and open halls. But in general, with us, this species breeds in chimneys; and haunts those stacks where there is a constant fire, for the sake of warmth; generally prefering one adjoining to the kitchen, and disregarding the perpetual smoke of that funnel. Five or six or more feet down the chimney does this little bird begin to form her nest about the middle of May, which consists, like that of the house martin, of a crust or shell composed of dirt or mud, mixed with short pieces of straw to render it tough and permanent; with this difference, that, whereas the shell of the martin is nearly hemispheric, that of the swallow is open at the top, and like half a deep dish. This nest is lined with fine grasses, which are often collected as they float in the air. Wonderful is the address (Mr. White observes) which this adroit bird shows all day long in ascending and descending through so narrow a pass. When hovering over the mouth of the funnel, the vibration of her wings acting on the confined air occasions a rumbling noise like thunder. It is probable that the dam submits to this inconvenient situation, so low in the shaft, in order to secure her brood from rapacious birds, and particularly from owls, which frequently fall down chimneys, perhaps in attempting to get at these nestlings. This bird lays from four to six white eggs, dotted with red specks; and brings out her first brood about the last week in June, or the

first in July. The progressive method by which the young are introduced into life is very curious: First, they emerge from the shaft with difficulty enough, and often fall down into the room below: for a day or so they are fed on the chimney top, and are then conducted to the dead leafless bough of some tree, where, sitting in a row, they are attended with great assiduity, and may then be called perchers. In a day or two more they become fliers, but are still unable to take their own food: therefore they play about near the place where the dams are hawking for flies; and when a mouthful is collected, at a certain signal given, the dam and the nestling advance, rising towards each other, and meeting at an angle; the young one all the while uttering such a little quick note of gratitude and complacency, that one must have paid very little regard to the wonders of Nature, who has not remarked this feat. The dam betakes herself immediately to the rearing of a second brood, as soon as she is disengaged from her first; which she at once associates with the first broods of house martins; and with them congregates, clustering on sunny roofs, towers, and trees. She brings out her second brood towards the middle and end of August. Every species of hirundo drinks as it flies along, sipping the surface of the water; but the swallow only washes on the wing, by dropping into a pool for many times together; in very hot weather house martins and bank martins dip and wash a little. The swallow is a delicate songster, and in soft sunny weather sings both perching and flying, on trees in a kind of concert, and on chimney tops: it is also a bold flier, ranging to distant towns and commons even in windy weather, which the other species seem much to dislike; nay, even frequenting seaport towns, and making little excursions over the salt-water. Horsemen on wide downs are often closely attended by a little party of swallows for miles together, which play before and behind them, sweeping around, and collecting all the sculking insects that are roused by the trampling of the horses' feet: when the wind blows hard, without this expedient, they are often forced to settle to pick up their lurking prey. This species feeds much on little coleoptera, as well as on gnats and flies; and often settles on dug ground, or paths, for gravel to grind and digest its food. Mr. Pennant says, that, for a few days previous to their departure, they assemble in vast flocks on house-tops, churches, and trees, from whence they take their flight. They are supposed to take up their winter quarters in Senegal and parts adjacent; and seem to possess in turn the whole of the old continent, being known from Norway to the Cape of Good Hope on the one hand, and from Kamtschatka to India and Japan on the other. They are also found in all parts of North America, migrating north and south as with us. Kalm says, that in America they build in houses and under the outsides of the roofs; also on the mountains, in such parts of them as project beyond the bottom, as well as under the corners of perpendicular

rocks.

12. H. urbica, the martin, is inferior in size to the chimney swallow, and its tail much less

forked. The head and upper part of the body, except the rump, are black glossed with blue: the breast, belly, and rump are white; the feet are covered with a short white down. They begin to appear about the 16th of April; and for some time they in general pay no attention to the business of nidification: they play and sport about, either to recruit from the fatigue of their journey, if they do migrate at all; or else that their blood may recover its true tone and texture after it has been so long benumbed by the severities of winter. About the middle of May, if the weather be fine, the martin begins to think in earnest of providing a mansion for its family. The crust or shell of this nest seems to be formed of such dirt or loam as comes most readily to hand, and is tempered and wrought together with little bits of broken straws to render it tough and tenacious. As this bird often builds against a perpendicular wall, without any projecting ledge under, it requires its utmost efforts to get the first foundation firmly fixed, so that it may safely carry on the superstructure. On this occasion the bird not only clings with its claws, but partly supports itself by strongly inclining its tail against the wall, making that a fulcrum; and, thus steadied, it works and plasters the materials into the face of the brick or stone. But then, that this work may not, while it is soft and green, pull itself down by its own weight, the provident architect has prudence and forbearance enough not to advance her work too fast; but by building only in the morning, and by dedicating the rest of the day to food and amusement, gives it sufficient time to dry and harden. About half an inch seems to be a sufficient layer for a day. By this method, in about ten or twelve days, is formed an hemispheric nest, with a small aperture towards the top, strong, compact, and warm; and perfectly fitted for all the purposes for which it was intended. But then nothing is more common than for the house sparrow, as soon as the shell is finished, to seize on it as its own, to eject the owner, and to line it after its own manner. After so much labor is bestowed in erecting a mansion, as nature seldom works in vain, martins will breed on for several years together in the same nest, where it happens to be well sheltered and secure from the injuries of the weather. The shell or crust of the nest is a sort of rustic work, full of knobs and protuberances on the outside: nor is the inside of those that I have examined smoothed with any exactness at all; but it is rendered soft and warm, and fit for incubation, by a lining of small straws, grasses, and feathers; and sometimes by a bed of moss interwoven with wool. In this they tread or engender frequently during the time of building; and the hen lays from three to five white eggs. At first, when the young are hatched, and are in a naked and helpless condition, the parent birds, with tender assiduity, carry out what comes from their young. Were it not for this affectionate cleanliness, the nestlings would soon be burnt up and destroyed in so deep and hollow a nest, by their own caustic excrement. As soon as the young are able to shift for themselves, the dams immediately turn their thoughts