nests; and whether the heronry consists of a whole grove or wood, or only of a few trees. It gave me satisfaction to find we accorded so well about the caprimulgus: all I contended for was to prove that it often chatters sitting as well as flying; and therefore the noise was voluntary, and from organic impulse, and not from the resistance of the air against the hollow of its mouth and throat. If ever I saw anything like actual migration, it was last Michaelmas-day. I was travelling, and out early in the morning: at first there was a vast fog; but, by the time that I was got seven or eight miles from home towards the coast, the sun broke out into a delicate warm day. We were then on a large heath or common, and I could discern, as the mist began to break away, great numbers of swallows (hirundines rustica) clustering on the stunted shrubs and bushes, as if they had roosted there all night. As soon as the air became clear and pleasant they all were on the wing at once; and, by a placid and easy flight, proceeded on southward towards the sea: after this I did not see any more flocks, only now and then a straggler. I cannot agree with those persons who assert that the swallow kind disappear gradually, as they come, for the bulk of them seem to withdraw at once: only some few stragglers stay behind a long while, and never, there is reason to believe, leave this island. Swallows seem to lay themselves up, and to come forth in a warm day, as bats do continually of a warm evening, after they have disappeared for weeks. For a very respectable gentleman assured me that, as he was walking with some friends under Merton wall on a remarkably hot noon, either in the 99 last week in December or the first week in January, he espied three or four swallows huddled together on the moulding of one of the windows of that college. I have frequently remarked that swallows are seen later at Oxford than elsewhere: is this owing to the vast massy buildings of that place, to the many waters round it, or to what else? When I used to rise in a morning last autumn, and see the swallows and martins clustering on the chimnies and thatch of the neighbouring cottages, I could not help being touched with a secret delight, mixed with some degree of mortification: with delight to observe with how much ardour and punctuality those poor little birds obeyed the strong impulse towards migration, or hiding, imprinted on their minds by their great Creator; and with some degree of mortification, when I reflected that, after all our pains and inquiries, we are yet not quite certain to what regions they do migrate; and are still farther embarrassed to find that some do not actually migrate at all. These reflections made so strong an impression on my imagination, that they became productive of a composition that may perhaps amuse you for a quarter of an hour when next I have the honour of writing to you. SELBORNE, February 28, 1769. LETTER XXIV. TO THOMAS PENNANT, ESQ. HE scarabæus fullo I know very well, having seen it in collections; but have never been able to discover one wild in its natural state. Mr. Banks told me he thought it might be found on the sea coast. On the 13th of April I went to the sheep-down, where the ring-ousels have been observed to make their appearance at spring and fall, in their way perhaps to the north or south; and was much pleased to see three birds about the usual spot. We shot a cock and a hen; they were plump and in high condition. The hen had but very small rudiments of eggs within her, which proves they are late breeders; whereas those species of the thrush kind that remain with us the whole year have fledged young before that time. In their crops was nothing very distinguishable, but somewhat that seemed like blades of vegetables nearly digested. In autumn they feed on haws and yew-berries, and in the spring on ivyberries. I dressed one of these birds, and found it juicy and well-flavoured. It is remarkable that they only stay a few days in their spring visit, but rest nearly a fortnight at Michaelmas. These birds, from the observations of three springs and two autumns, are most punctual in their return; and exhibit a new migration unnoticed by the writers, who supposed they never were to be seen in any of the southern counties. One of my neighbours lately brought me a new salicaria, which at first I suspected might have provod your willow-lark; but, on a nicer examination, it answered much better to the description of that species which you shot at Revesby, in Lincolnshire. My bird I describe thus:-"It is a size less than the grasshopper-lark; the head, back, and coverts of the wings, of a dusky brown, without those dark spots of the grasshopper-lark; over each eye is a milkwhite stroke; the chin and throat are white, and the under parts of a yellowish white; the rump is tawny, and the feathers of the tail sharp-pointed; the bill is dusky and sharp, and the legs are dusky; the hinder claw long and crooked." The person that shot it says that it sung so like a reed-sparrow that he took it for one; and that it sings all night: but this account merits farther inquiry. For my part, I suspect it is a second sort of locustella, hinted at by Dr. Derham in "Ray's Letters." He also procured me a grasshopper-lark. The question that you put with regard to those genera of animals that are peculiar to America, viz. how they came there, and whence? is too puzzling for me to answer; and yet so obvious as often to have struck me with wonder. If one looks into the writers on that subject little satisfaction is to be For this salicaria, or Sedge Warbler, see Letter XXVI. Angust 30, 1769. found. Ingenious men will readily advance plausible arguments to support whatever theory they shall choose to maintain; but then the misfortune is, every one's hypothesis is each as good as another's, since they are all founded on conjecture. The late writers of this sort, in whom may be seen all the arguments of those that have gone before, as I remember, stock America from the western coast of Africa and the south of Europe; and then break down the Isthmus that bridged over the Atlantic. But this is making use of a violent piece of machinery: it is a difficulty worthy of the interposition of a god! "Incredulus odi." "I feel disgusted and disbelieving." THE NATURALIST'S SUMMER-EVENING WALK. -equidem credo, quia sit divinitus illis VIRG. Georg. I. 415, 416. Ingenium.* WHEN day declining sheds a milder gleam, What time the May-fly † haunts the pool or stream; "I think their instinct is divinely bestowed.' †The angler's May-fly, the Ephemera vulgata, Linn. comes forth from its aurelia state, and emerges from the water about six in the evening, and dies about eleven at night, determining its fly state in about five or six hours. It usually begins to appear about the 4th of June, and continues in succession for nearly a fortnight.-ED. Vagrant cuckoo; so called because, being tied down by no incubation or attendance on the nutrition of its young, it wanders without control.-ED. Charadrius oedicnemus. |