grain, considering the great improvements of modern husbandry. Such a run of wet seasons a century or two ago, would, I am persuaded, have occasioned a famine. Therefore pamphlets and newspaper letters, that talk of combinations, tend to inflame and mislead; since we must not expect plenty till Providence sends us more favourable seasons.

The wheat of last year, all round this district, and in the county of Rutland, and elsewhere, yields remarkably bad: and our wheat on the ground, by the continual late sudden vicissitudes from fierce frost to pouring rains, looks poorly; and the turnips rot very fast.

I am, &c.

LETTER XX.

TO THE SAME.

DEAR SIR,

SELBORNE, Feb. 26, 1774. THE sand martin, or bank martin, is by much the least of any of the British Hirundines; and, as far as we have ever seen, the smallest known Hirundo: though Brisson asserts that there is one much smaller, and that is the Hirundo esculenta.

But it is much to be regretted that it is scarce possible for any observer to be so full and exact as he could wish in reciting the circumstances attending the life and conversation of this little bird, since it is fera naturâ, at least in this part of the kingdom, disclaiming all domestic attachments, and haunting wild heaths and commons where there are large lakes; while the other species, especially the swallow and house martin, are remarkably gentle and domesticated, and never seem to think themselves safe but under the protection of man.

Here are in this parish, in the sand pits and banks of the lakes of Wolmer Forest, several colonies of these

birds; and yet they are never seen in the village; nor do they at all frequent the cottages that are scattered about in that wild district. The only instance I ever remember where this species haunts any building is at the town of Bishop's Waltham, in this county, where many sand martins nestle and breed in the scaffold holes of the back wall of William of Wykeham's stables: but then this wall stands in a very sequestered and retired enclosure, and faces upon a large and beautiful lake. And indeed this species seems so to delight in large waters, that no instance occurs of their abounding, but near vast pools or rivers: and in particular it has been remarked that they swarm in the banks of the Thames in some places below London Bridge.

It is curious to observe with what different degrees of architectonic skill Providence has endowed birds of the same genus, and so nearly correspondent in their general mode of life! for while the swallow and the house martin discover the greatest address in raising

and securely fixing crusts or shells of loam as cunabula for their young, the bank martin 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 this bird deposit, in a good degree of safety, her rude nest, consisting of fine grasses and feathers, usually goose feathers, very inartificially laid together.

Perseverance will accomplish any thing: though at first 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 dispatch: and could remark how much they had scooped that day by the fresh sand which ran down the bank, and was of different colour 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, for reasons given above; but it would be a matter worthy of observation, where it falls in the way of any naturalist to make his remarks. This I have often taken notice of, that several holes of different depths are left unfinished at the end of summer. To

imagine that these beginnings were intentionally made in order to be in the greater forwardness for next spring, is allowing perhaps too much foresight and rerum prudentia to a simple bird. May not the cause of these latebræ being left unfinished arise from their meeting in those places with strata too harsh, hard, and solid, for their purpose, which they relinquish, and go to a fresh spot that works more freely? Or may they not in other places fall in with a soil as much too loose and mouldering, liable to founder, and threatening to overwhelm them and their labours?

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 moreover is strangely annoyed with fleas and we have seen fleas, bed fleas (Pulex irritans1), swarming at the mouths of these holes, like bees on the stools of their hives.

The following circumstance should by no means be omitted-that these birds do not make use of their

The flea of the sand martin, although to the unassisted eye so exceedingly similar to the bed flea as to be scarcely distinguishable from it, is altogether distinct. It appears even to be distinct from the flea of the swallow, named by Mr. Stephens Pulex Hirundinis; and has been indicated by Mr. Curtis under the appellation of bifasciatus. By the latter the sand martin's flea is referred to a genus separated by him from the ordinary flea, Pulex, LINN., and distinguished by the name of Ceratophyllus he having discovered that the antennæ of the numerous insects referrible to this last-named group have four or more joints; while in Pulex irritans and its congeners those organs are only two-jointed.

Although it was stated by Latreille, so long since as the date of the publication of his Genera Crustaceorum et Insectorum, that fleas possess antennæ, which he described as being situated on each side in a cavity behind the eye, the minuteness of these little creatures rendering their examination difficult, obstructed until about three years since the verification of the fact by others: Latreille himself appearing, in 1829, to have hesitated in averring it with the same certainty that he had expressed upwards of twenty years before. In 1832, however, Mr. Haliday and Mr. Curtis in England, and later in the year, M. Dugès in France, rediscovered these organs: and figures of them, as they were observed in several species, were given in the British Entomology and in the Annales

caverns by way of hybernacula, as might be expected; since banks so perforated have been dug out with care in the winter, when nothing was found but empty nests.

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 business of nidification, incubation, and the support of its young in the dark, it would not be so 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 Libel lulæ (dragon-flies) almost as long as themselves. In the last week in June we have seen a row of these sitting on a rail near a great pool as perchers; and so young and helpless, as easily to be taken by hand: but whether the dams ever feed them on the wing, as swallows and house martins do, we have never yet been able to determine: nor do we know whether they pursue and attack birds of prey.

When they happen to breed near hedges and enclosures, they are dispossessed of their breeding holes by

des Sciences Naturelles. It may aid those who may be disposed to search for so minute an organ on so small a creature to be informed that, according to M. Dugès, there is behind each eye a shallow but broad cavity, ending below in a cleft and covered by a kind of operculum which is triangular and immoveable: an arrangement which he compares to the orbit, the temporal fossa, and the zygoma of the human skull. Under the operculum and within the cleft is hidden a small flat body, which is raised, at times, briskly into the uncovered portion of the depression. This is the antenna, of larger size than is well adapted to the small space in which it is lodged, and rendered capable of being contained in so limited a cavity only by the flexures of its joints. The number or the form of these joints appears to differ in almost every one of the indigenous fleas, nearly twenty of which have now been discovered infesting various quadrupeds and birds; each of them being generally appropriated to its peculiar species.

The sand martin's flea remains in considerable numbers in the deserted nests after the departure of the bird.-E. T. B.