not understand perfectly; but refer it to the observation of the curious anatomist. These creatures send forth a very rancid and offensive smell.* LETTER XLVII. TO THOMAS PENNANT, ESQ. SELBORNE, 1771. DEAR SIR,- On the twelfth of July, I had a fair opportunity of contemplating the motions of the caprimulgus, or fern-owl, as it was playing round a large oak that swarmed with scarabaei *Mr Jesse says, "Bats seem to be gregarious animals. Vast numbers of them were lately found under the roof of an old building in Richmond Park. I had two sorts of them brought to me, nearly similar in shape, but one very considerably larger than the other. This latter is probably the vespertilio altivolans, mentioned by Mr White, in his Natural History of Selborne, answering to his description of it. It measured nearly fifteen inches from the tip of one wing to that of the other. These larger bats were quite as numerous as the smaller species. A great number of them were also found in an old building in Combe Wood, adjoining Richmond Park; and, subsequently, ten of them were discovered in a decayed tree in that park." This is pretty strong evidence against the migration of the bat in question. Several of these were sent by Mr Jesse to the Zoological Societies of London. A workman employed in the repairs of Cardinal Wolsey's hall, Hampton-Court Palace, found the skeleton of a bat at the end of one of the rafters of the ceiling, which is calculated to have been nearly as large as a pigeon when alive. Bats are possessed of a sense with which we are yet unacquainted, that of avoiding objects in the dark. Spallanzani hung up some cloths across a room, with holes cut in them at various distances, large enough to allow a bat to fly through. He deprived the poor animals of light, and stopt their hearing as much as possible. These animals on being turned loose, flew through the perforations with as much correctness as if they had had the use of their eyes. Respecting the hybernation of the bat, the following fact is very curious: "In the beginning of November, 1821, a woodman engaged in splitting timber for rails in the woods close to the lake at Haining, a seat of Mr Pringle in Selkirkshire, discovered in the centre of a large wild cherry tree, a living bat, of a bright scarlet colour, which, as soon as it was relieved from its entombment, took to its wings and escaped. In the tree there was a recess sufficiently large to contain the animal; but all around the wood was perfectly sound, solid, and free from any fissure through which the atmosphere could reach the animal. A man employed in the same manner at Kelsall, in December, 1826, met with a similar phenomenon, and allowed the bat to escape, under the influence of fear, protesting that it was not a being of this world." Blackwood's Magazine, vol. viii. p. 467. — ED. solstitiales, or fern-chaffers. The powers of its wing were wonderful, exceeding, if possible, the various evolutions and quick turns of the swallow genus. But the circumstance that pleased me most was, that I saw it distinctly more than once put out its short leg when on the wing, and, by a bend of the head, deliver somewhat into its mouth. If it takes any part of its prey with its foot, as I have now the greatest reason to suppose it does these chaffers, I no longer wonder at the use of its middle toe, which is curiously furnished with a serrated claw.* Swallows and martins- -the bulk of them, I mean-have forsaken us sooner this year than usual; for, on September the 22d, they rendezvoused in a neighbour's walnut tree, where, it seemed probable, they had taken up their lodgings for the night. At the dawn of the day, which was foggy, they rose altogether in infinite numbers, occasioning such a rushing, from the strokes of their wings against the hazy air, as might be heard to a considerable distance: since that, no flock has appeared, only a few stragglers. Some swifts staid late, till the 22d of August; a rare instance for they usually withdraw within the first week.† On September the 24th, three or four ringousels appeared in my fields, for the first time this season. How punctual are these visitors in their autumnal and spring migrations! LETTER XLVIII. TO THE HON. DAINES BARRINGTON. SELBORNE, February 8, 1772. DEAR SIR, When I ride about in winter, and see such prodigious flocks of various kinds of birds, I cannot help * The use of the serrated claw of the goat-sucker has occasioned much controversy amongst naturalists within the last few years, but is satisfactorily accounted for by Wilson, in his description of the Carolina nightjar. "Their mouths," says he, "are capal le of prodigious expansion, to seize their prey with more certainty, and furnished with long hairs or bristles, serving as palisades to secure what comes between them. Reposing much during the heat of day, they are greatly infested with vermin, particularly about the head, and are provided with a comb on the under edge of the middle claw, with which they are often employed in ridding themselves of these pests, at least when in a state of captivity." ED. + See letter XCVII. to the Hon. Daines Barrington.-In the Magazine of Natural History, we are informed that swifts were seen at Chipping Norton, on the 27th September, 1830.—ED. admiring at these congregations, and wishing that it was in my power to account for those appearances, almost peculiar to the season. The two great motives which regulate the proceedings of the brute creation, are love and hunger: the former incites animals to perpetuate their kind, the latter induces them to preserve individuals. Whether either of these should seem to be the ruling passion, in the matter of congregating, is to be considered. As to love, that is out of the question, at a time of the year when that soft passion is not indulged; besides, during the amorous season, such a jealousy prevails between the male birds, that they can hardly bear to be together in the same hedge or field. Most of the singing and elation of spirits of that time, seem to me to be the effect of rivalry and emulation; and it is to this spirit of jealousy, that I chiefly attribute the equal dispersion of birds in the spring, over the face of the country. Now as to the business of food. As these animals are actuated by instinct to hunt for necessary food, they should not, one would suppose, crowd together in pursuit of sustenance, at a time when it is most likely to fail; yet such associations do take place in hard weather chiefly, and thicken as the severity increases. As some kind of self-interest and self-defence is, no doubt, the motive for the proceeding, may it not arise from the helplessness of their state in such rigorous seasons, as men crowd together, when under great calamities, though they know not why? Perhaps approximation may dispel some degree of cold; and a crowd may make each individual appear safer from the ravages of birds of prey, and other dangers. If I admire when I see how much congenerous birds love to congregate, I am the more struck when I see incongruous ones in such strict amity.* If we do not much wonder to see a flock of rooks usually attended by a train of daws, yet it is strange that the former should so frequently have a flight of starlings for their satellites. † Is it because rooks have a more *There is nothing more strange in starlings and rooks being seen in company, than for the short-eared owl to be seen amongst flights of woodcocks. Pennant mentions simultaneous migrations of cuckoos and turtle-doves having been noticed in Greece. The author of the Journal of a Naturalist, speaking of the readiness with which rooks detect the places where grubs are sure to be found, says, "I have often observed them alight on a pasture of uniform verdure, and exhibiting no sensible appearance of feathering or decay, and imme diately commence staking up the ground. Upon investigating the object of their operations, I have found the heads of plantains, the little autumnal discerning scent than their attendants, and can lead them to spots more productive of food? Anatomists say that rooks, by reason of two large nerves which run down between the eyes into the upper mandible, have a more delicate feeling in their beaks than other round-billed birds, and can grope for their meat when out of sight. Perhaps, then, their associates attend them on the motive of interest, as greyhounds wait on the motions of their finders, and as lions are said to do on the yelpings of jackals. Lapwings and starlings sometimes associate.* dandelions, and other plants, drawn out of the ground and scattered about, their roots having been eaten off by a grub, leaving only a crown of leaves upon the surface. This grub beneath, in the earth, the rooks had detected in their flight, and descended to feed on it, first pulling up the plant which concealed it, and then drawing the larvæ from their holes." A correspondent, in the Magazine of Natural History, proves that the rook is occasionally a predatory bird. He says, "As I was passing through Chandos Street, Cavendish Square, London, soon after six o'clock this morning, my attention was attracted to a rook flying low, near the walls of some out-buildings, in which were many holes occupied by sparrows' nests. He directed his flight to one of these holes, into which he thrust himself as far as possible. It was evident that he was attempting to reach something with his bill; but apparently he did not succeed, for he shortly withdrew himself from this hole, and flew to another, into which he intruded himself in the same manner. From this second hole he retired almost immediately, bearing in his beak one of the callow brood. He flew with his spoil to a high chimney at the corner house, followed for a short distance by ten or twelve sparrows, clamouring loudly at such an atrocious robbery; and one sparrow, probably the parent, ventured to pursue even to the chimney-top, as if determined to assail the fell destroyer; but both the rook and the sparrow quickly disappeared behind the chimney-pot, and prevented my farther observation." Colonel Montagu records an instance of great sagacity in rooks. He noticed two of them by the sea shore, after having satisfied the calls of hunger, busy in removing small fish beyond the flux of the tide, and depositing them just above high water mark under the broken rocks.-.ED. Lapwings are invariably gregarious, assembling in very large flocks in the autumn. At this time they are esteemed excellent food. The starlings also congregate in autumn. We saw a flight of these birds in the autumn of 1814, in Kings County, Ireland, which literally darkened the air, and must have consisted of at least a hundred thousand; they were flying near the immense marshy plain near Banacher, through which the Shannon flows. "In the autumnal and hyemal months," says Selby, "these birds gather in immense flocks, and are particularly abundant in the fenny parts of Nottinghamshire and Lincolnshire, where they roost among the reeds. Before they retire to rest, they perform various manoeuvres in the air, the whole frequently describing rapid revolutions round a common centre. This peculiar flight will sometimes continue for nearly half an hour before they become finally settled for the night. Upon the approach of spring they spread themselves over the whole country."-ED. LETTER XLIX. TO THE HON. DAINES BARRINGTON. March 9, 1772. DEAR SIR, As a gentleman and myself were walking, on the 4th of last November, round the sea-banks at Newhaven, near the mouth of the Lewes river, in pursuit of natural knowledge, we were surprised to see three house swallows gliding very swiftly by us. That morning was rather chilly, with the wind at north-west; but the tenor of the weather, for some time before, had been delicate, and the noons remarkably warm. From this incident, and from repeated accounts which I meet with, I am more and more induced to believe, that many of the swallow kind do not depart from this island, but lay themselves up in holes and caverns, and do, insect-like, and bat-like, come forth at mild times, and then retire again to their latebræ. Nor make I the least doubt but that, if I lived at Newhaven, Seaford, Brighthelmstone, or any of those towns near the chalk cliffs of the Sussex coast, by proper observations, I should see swallows stirring at periods of the winter, when the noons were soft and inviting, and the sun warm and invigorating. And I am the more of this opinion, from what I have remarked during some of our late springs, and though some swallows did make their appearance about the usual time, viz. the 13th or 14th of April, yet, meeting with a harsh reception, and blustering, cold, north-east winds, they immediately withdrew, absconding for several days, till the weather gave them better encouragement. LETTER L. TO THOMAS PENNANT, ESQ. April 12, 1772. DEAR SIR,- While I was in Sussex last autumn, my residence was at the village near Lewes, from whence I had formerly the pleasure of writing to you. On the 1st of November, I remarked that the old tortoise, formerly mentioned, began first to dig the ground, in order to the forming of its hybernaculum, which it had fixed on just beside a great turf of hepaticas. It scrapes out the ground with its fore feet, and throws it up over its back with its hind; but the |