Abbildungen der Seite
PDF
EPUB

VIUT TE LYON Biblioth. du Palais des Arts

is said to haunt the mouth of the Lewes river, near Newhaven; and the Cornish chough builds, I know, all along the chalky cliffs of the Sussex shore.

I was greatly pleased to see little parties of ring-ousels

downwards; the same process in the cross-bill is spherical. The cavity in the lower jaw, destined to receive this process, is a hollow circular cup. The union of these two portions, therefore, forms an articulation possessing the universal motion and flexibility of the mechanical ball-and-socket joint. The lower jaw is of great strength, the sides or plates elevated, with prominent coronoid processes, to which, as well as to the whole outer sides of the plates, the temporal muscle is attached ; and in a head of this bird, which had been divested of all the soft parts, I found, on sliding the lower laterally upon the upper, as performed by the bird, that, before the coronoid process is brought into contact with the pterygoid, on its own side, the extreme points of the mandibles were separated laterally to the extent I have already mentioned of 3-8ths of an inch. The temporal and pyramidal muscles on the right side of the head (that being the side to which the lower jaw inclined,) were considerably larger than those of the left, and indicated by their bulk the great lateral power this bird is capable of exerting, to be hereafter noticed. The unusually large size of the pterygoid muscles, on each side, was very conspicuous, the space for them being obtained by the great distance to which the articulated extremities of the lower jaw were removed ; and the food of the bird being small seeds, rendered a narrow pharynx sufficient for the purpose of swallowing. The muscles depressiug the lower mandible are three in number, only one of which, the greater pyramidal, is visible. This strong muscle covers two other small ones, the triangular and square muscles, so called from their particular shape. These three muscles, all of which have their origin in the occipital portion of the cranium, are inserted by strong tendons on the under and back of each extremity of the lower jaw, behind the centre of motion, and, consequently, by their simultaneous contraction, raise the point to which they are attached, and depress the anterior part of the mandible. The lower portions of the ossa quadrata are pushed somewhat forwards by this compression, assisted by two small muscles; one of these, a small flat muscle, arises from the septum of the orbits, behind the small aperture observed in the septum, and passes downwards to be inserted upon the projecting styloid process of the os quadratum. The second is a small pyramidal-shaped muscle, arising also from the septum, anterior to the other muscle, and, passing downwards and backwards, is inserted upon the omoideum, both by their contraction pulling the os quadratum forwards, and thus elevating the other mandible. The depressors of the lower jaw, and the elevators of the upper, therefore, act together to separate the mandibles. To close the mandibles, the temporal and pterygoid muscles elevate the lower jaw, assisted by slender slips, which, extending forwards to the superior maxillary bones, act in concert, by bringing them down. When the lateral motion is required, the great pyramidal muscle on the right side pulls the extremity of the lower jaw, to which it is attached, backwards, the pterygoid muscles on the left side at the same time powerfully assisting, by carrying that side of the lower jaw inwards.”

Mr. Yarrel next goes on to explain the use of the tongue. Their food is

visit us

(my newly-discovered migrators), scattered, at intervals, all along the Sussex downs from Chichester to Lewes. Let them come from whence they will, it looks very suspicious that they are cantoned all along the coast, in order to pass the Channel, when severe weather advances. Th again in April, as it should seem, in their return, and are not to be found in the dead of winter. It is remarkable that they are very tame, and seem to have no manner of apprehensions of danger from a person with a gun. There are bustards on the wide downs near Brighthelmstone. No doubt you are acquainted with the Sussex downs. The prospects and rides round Lewes are most lovely.

As I rode along near the coast I kept a very sharp lookout in the lanes and woods, hoping I might, at this time of the year,

have discovered some of the summer short-winged birds of passage crowding towards the coast, in order for

the seeds of the different fir-cones ; and their mode of operation, when proceeding to extract them, is this :— They first fix themselves across the cone ; then, bringing the points of the maxilla from their crossed or lateral position to lie immediately over each other, in this reduced compass they insinuate their beaks between the scales, and then opening them, not in the usual manner, but by drawing the inferior maxilla sideways, force open the scales. Mr. Yarrel then proceeds : :-" At this stage of the proceeding, the aid of the tongue becomes necessary, and this organ is no less admirably adapted for the service required. The os hyoides, or bone of the tongue, has articulated to its anterior extremity an additional portion, formed partly of bone, with a horny covering. In shape it is narrow, about 3-8ths of an inch in length, and extends downwards and forwards, the sides curved upwards, the distal extremity shaped like a scoop, somewhat pointed and thin on both edges, the proximal extremity ending in two small processes, elongated upwards and backwards above the articulation with the bone of the tongue, each process having inserted upon it a slender muscle extending backwards to the glottis, and attached to the os hyoides, which muscles, by their contraction, extend and raise the scoop-like point; underneath the articulation of this horny and grooved appendage is another small muscle, which is attached at one extremity to the os hyoides, at the other to the moveable piece, and, by its action, as an antagonist to the upper muscles, bends the point downwards and backwards ; while, therefore, the point of the beak presses the shell from the body of the cone, the tongue, brought forward by its own muscle (genio-hyoideus), is enabled, by the additional muscles described, to direct and insert its cutting scoop underneath the seed, and the food thus dislodged is transferred to the mouth ; and, when the mandibles are separated laterally in this operation, the bird has an uninterrupted view of the seed in the cavity, with the eye on that side to which the under mandible is curved."

For farther information consult Zoological Journal, vol. iv. p. 459.-W.J.

their departure; but it was very extraordinary that I never saw a red-start, white-throat, black-cap, uncrested wren, flycatcher, &c.; and I remember to have made the same remark in former years, as I usually come to this place annually about this time. The birds most common along the coast, at present, are the stone-chatters, whin-chats, buntings, linnets, some few wheat-ears, titlarks, &c. Swallows and housemartins abound yet, induced to prolong their stay by this soft, still, dry season.

Á land-tortoise, which has been kept for thirty years in a little walled court belonging to the house where I am now visiting, retires under ground about the middle of November, and comes forth again about the middle of April. When it first appears in the spring, it discovers very little inclination towards food, but in the height of summer grows voracious, and then, as the summer declines, its appetite declines; so that for the last six weeks in autumn it hardly eats at all. Milky plants, such as lettuces, dandelions, sow-thistles, are its favourite dish. In a neighbouring village one was kept till, by tradition, it was supposed to be an hundred -an instance of vast longevity in such a poor reptile !

years old,

LETTER XXXIX.

TO THOMAS PENNANT, ESQ.

SELBORNE, Oct. 29, 1770. DEAR SIR,—After an ineffectual search in Linnæus, Brisson, &c., I begin to suspect that I discern my brother's hirundo hyberna in Scopoli's new-discovered hirundo rupestris, p. 167. His description of “Supra murina, subtus albida; tectrices maculâ ovali albâ in latere interno ; pedes nudi, nigri; rostrum nigrum ; remiges obscuriores quam plume dorsales; rectrices remigibus concolores ; caudâ emarginatâ nec forcipata," agrees very well with the bird in question; but when he comes to advance that it is “statura hirundinis urbice," and that definito hirundinis riparia Linnæi huic quoque convenit,” he, in some measure, invalidates all he has said ;

at least, he shows at once that he compares them to these species merely from memory; for I have compared the birds themselves, and find they differ widely in every circumstance of shape, size, and colour. However, as you will have a specimen, I shall be glad to hear what your judgment is in the matter.

Whether my brother is forestalled in his nondescript or not, he will have the credit of first discovering that they spend their winters under the warm and sheltery shores of Gibraltar and Barbary.

Scopoli's characters of his Ordines and Genera are clear, just, and expressive, and much in the spirit of Linnæus. These few remarks are the result of my first perusal of Scopoli's Annus Primus.

The bane of our science is the comparing one animal to the other by memory. For want of caution in this particular, Scopoli falls into errors. He is not so full with regard to the manners of his indigenous birds as might be wished, as you justly observe: his Latin is easy, elegant, and expressive, and very superior to Kramer's.*

LETTER XL.

TO THE SAME.

SELBORNE, Nov. 26, 1770. DEAR SIR,I was much pleased to see, among the collection of birds from Gibraltar, some of those short-winged English summer birds of passage, concerning whose departure we have made so much inquiry. Now, if these birds are found, in Andalusia, to migrate to and from Barbary, it may easily be supposed that those that come to us may migrate back to the continent, and spend their winters in some of the warmer parts of Europe. This is certain, that many soft-billed birds that come to Gibraltar appear there only in spring and

. See his Elenchus Vegetabilium et Animalium per Austriam Inferiorem, doc.,—“Summary of Vegetables and Animals in Lower Austria.”

« ZurückWeiter »