drop from them. That they are best pleased with such jejune diet may easily be confuted, since, if you toss them crumbs they will seize them with great readiness, not to say greediness: however, bread should be given sparingly, lest, turning sour, it corrupt the water. They will also feed on the water-plant called Lemna (duck's meat), and also on small fry.

When they want to move a little, they gently protrude themselves with their pinna pectorales; but it is with their strong muscular tails only that they and all fishes shoot along with such inconceivable rapidity. It has been said that the eyes of fishes are immoveable; but these apparently turn them forward or backward in their sockets as their occasions require. They take little notice of a lighted candle, though applied close to their heads, but flounce and seem much frightened by a sudden stroke of the hand against the support whereon the bowl is hung, especially when they have been motionless, and are perhaps asleep. As fishes have no eyelids, it is not easy to discern when they are sleeping or not, because their eyes are always

open.

Nothing can be more amusing than a glass bowl containing such fishes: the double refractions of the glass and water represent them, when moving, in a shifting and changeable variety of dimensions, shades, and colours; while the two mediums, assisted by the concavo-convex shape of the vessel, magnify and distort them vastly; not to mention that the introduction of another element and its inhabitants into our parlours engages the fancy in a very agreeable manner.

Gold and silver fishes, though originally natives of China and Japan, yet are become so well reconciled to our climate as to thrive and multiply very fast in our ponds and stews. Linnæus ranks this species of fish under the genus of Cyprinus, or carp, and calls it Cyprinus auratus.

Some people exhibit this sort of fish in a very fanciful way, for they cause a glass bowl to be blown with a large hollow space within, that does not communicate with it. In this cavity they put a bird occasionally; so that you may

see a goldfinch or a linnet hopping, as it were, in the midst of the water, and the fishes swimming in a circle round it. The simple exhibition of the fishes is agreeable and pleasant, but in so complicated a way becomes whimsical and unnatural, and liable to the objection due to him,

"Qui variare cupit rem prodigialitèr unam."

LETTER LV.

TO THE HONOURABLE DAINES BARRINGTON.

October 10, 1781.

THINK I have observed before that much the most considerable part of the house martins withdraw from hence about the first week in October; but that some, the latter broods, I am now convinced, linger on till towards the middle of that month; and that at times, once perhaps in two or three years, a flight, for one day only, has shown itself in the first week in November.

Having taken notice, in October, 1780, that the last flight was numerous, amounting perhaps to one hundred and fifty, and that the season was soft and still, I was resolved to pay uncommon attention to these late birds, to find, if possible, where they roosted, and to determine the precise time of their retreat. The mode of life of these latter Hirundines is very favourable to such a design, for they spend the whole day in the sheltered districts, between me and the Hanger, sailing about in a placid, easy manner, and feasting on those insects which love to haunt a spot so secure from ruffling winds. As my principal object was to discover the place of their roosting, I took care to wait on them before they retired to rest, and was much pleased to find that, for several evenings together, just at a quarter past five in the afternoon, they all scudded away in great haste towards the south-east, and darted down among the

This

low shrubs above the cottages at the end of the hill. spot in many respects seems to be well calculated for their winter residence: for in many parts it is as steep as the roof of any house, and, therefore, secure from the annoyances of water; and it is, moreover, clothed with beechen shrubs, which, being stunted and bitten by sheep, make the thickest covert imaginable, and are so entangled as to be impervious to the smallest spaniel: besides, it is the nature of underwood beech never to cast its leaf all the winter, so that, with the leaves on the ground, and those on the twigs, no shelter can be more complete. I watched them on to the 13th and 14th of October, and found their evening retreat was exact and uniform; but after this they made no regular appearance. Now and then a straggler was seen; and, on the 22nd of October, I observed two, in the morning, over the village, and with them my remarks for the season ended.

From all these circumstances put together, it is more than probable that this lingering flight, at so late a season. of the year, never departed from the island.1 Had they indulged me that autumn with a November visit, as I much desired, I presume that, with proper assistants, I should have settled the matter past all doubt; but though the 3rd of November was a sweet day, and in appearance exactly suited to my wishes, yet not a martin was to be seen, and so I was forced, reluctantly, to give up the pursuit.

I have only to add, that were the bushes, which cover some acres, and are not my own property, to be grubbed and carefully examined, probably those late broods, and perhaps the whole aggregate body of the house martins of

1 Upon this passage the Rev. Mr. Herbert remarks that the author appears to have a strong bias to believe that martins, &c., remain dormant in this country, having "taken up a very erroneous notion of the difficulty of the passage," and "drawing from circumstances probabilities which are not justified by his statements." It is scarcely necessary at the present day, either to follow or support Mr. Herbert in his arguments against hybernation, and in favour of migration, since all well. informed naturalists are now agreed that the theory advanced by Gilbert White is untenable. Were any proof of migration required, much stronger evidence than that adduced by Mr. Herbert could readily be supplied.-ED.

this district, might be found there, in different secret dor mitories; and that, so far from withdrawing into warmer climes, it would appear that they never depart 300 yards from the village.

LETTER LVI.

TO THE HONOURABLE DAINES BARRINGTON.

HEY who write on natural history cannot too frequently advert to instinct, that wonderful limited faculty, which, in some instances, raises the brute creation as it were above reason, and in others leaves them so far below it. Philosophers have defined instinct to be that secret influence by which every species is impelled naturally to pursue, at all times, the same way or track, without any teaching or example; whereas reason, without instruction, would often vary and do that by many methods which instinct effects by one alone. Now this maxim must be taken in a qualified sense; for there are instances in which instinct does vary and conform to the circumstances of place and convenience.

It has been remarked that every species of bird has a mode of nidification peculiar to itself; so that a schoolboy would at once pronounce on the sort of nest before him. This is the case among fields and woods and wilds; but in the villages round London, where mosses and gossamer, and cotton from vegetables, are hardly to be found, the nest of the chaffinch has not that elegant, finished appearance, nor is it so beautifully studded with lichens, as in a more rural district; and the wren is obliged to construct its house with straws and dry grasses, which do not give it that rotundity and compactness so remarkable in the edifices of that little architect.1 Again, the regular nest of the house.

1

May not the use of bright and fresh materials in the country, and

martin is hemispheric; but where a rafter, or a joist, or a cornice may happen to stand in the way, the nest is so contrived as to conform to the obstruction, and becomes flat or oval or compressed.

In the following instances instinct is perfectly uniform and consistent. There are three creatures, the squirrel, the field-mouse, and the bird called the nuthatch (Sitta europaea),' which live much on hazel-nuts; and yet they open them each in a different way. The first, after rasping off the small end, splits the shell in two with his long fore teeth, as a man does with his knife; the second nibbles a hole with his teeth, so regular as if drilled with a wimble, and yet so small that one would wonder how the kernel can be extracted through it; while the last picks an irregular ragged hole with its bill: but as this artist has no paws to hold the nut firm while he pierces it, like an adroit workman, he fixes it, as it were, in a vice, in some cleft of a tree, or in some crevice; when, standing over it, he perforates the stubborn shell. We have often placed nuts in the chink of a gate-post where nuthatches have been known to haunt, and have always found that those birds have readily penetrated them. While at work they make a rapping noise that may be heard at a considerable distance.

You that understand both the theory and practical part of music may best inform us why harmony or melody should so strangely affect some men, as it were by recollection, for days after a concert is over. What I mean the following passage will most readily explain:

non

"Præhabebat porrò vocibus humanis instrumentisque harmonicis musicam illam avium: non quod aliâ quoque delectaretur; sed quod ex musicâ humanâ relinqueretur in

of those of a more sombre description in the neighbourhood of London be intended to answer the same purpose, namely, to render the nests secure from observation ?-ED

1 The Scandinavian nuthatch, described by Linnæus ("Syst. Nat." i. p. 177,) as Sitta europæa, differs from that found in Great Britain, and the latter, therefore, should be distinguished as Sitta cæsia, that being the oldest name applied by Meyer ("Taschenb. Deutsch. Vögel," 1. p. 128) to the same bird as observed in Germany.-ED.

U