breathing, but an offensive nauseous smell annoyed us. We now fastened a dog to the end of a bamboo, 18 feet long, and sent him in, we had our watches in our hands, and in 14 seconds he fell on his back, did not move his limbs or look round, but continued to breathe 18 minutes. We then sent in another, or rather he got loose from the bamboo, but walked in to where the other dog was lying: he then stood quite still, and in 10 seconds he fell on his face, and never moved his limbs afterwards: he continued to breathe for 7 minutes. We now tried a fowl, which died in 1 minute. We threw in another, which died before touching the ground. During these experiments we experienced a heavy shower of rain; but we were so interested by the awful scene before us, that we did not care for getting wet. On the opposite side, near a large stone, was the skeleton of a human being, who must have perished on his back, with the right arm under the head, from being exposed to the weather, the bones were bleached as white as ivory. I was anxious to procure this skeleton, but any attempt to get at it would have been madness. After remaining two hours in this Valley of Death, we returned, but found some difficulty in getting out. From the heavy shower, the sides of the valley were very slippery, and had it not been for two Javanese behind us, we might have found it no easy matter to escape from this pestilential spot. On reaching our rendezvous we had some brandy and water, and left this most extraordinary valley, came down the slippery footpath, sometimes on our hams and hands to the main road, mounted our horses, and returned to Balor, quite pleased with our trip. The human skeletons are supposed to have been rebels, who had been pursued from the main road, and taken refuge in the different valleys, as a wanderer cannot know his danger till he is in the valley, and when once there, one has not the power or presence of mind to return.

"There is a great difference between this valley and the Grotto del Cano, near Naples, where the air is confined to a small aperture; while here the circumference is fully half a mile, and not the least smell of sulphur, nor any appearance of an eruption ever having taken place near it, although I am aware that the whole chain of mountains is volcanic, as there are two craters

at no great distance from the side of the road at the foot of the Djienz, and they constantly emit smoke."-Fahr. 52°.

In the 8th volume of the proceedings of the Batavian Society of Arts and Sciences, Dr Horsefield of the East India House, gives a description of the mineral constitution of the different mountains of Java. He examined several parts of the chain of hills, and states that he heard of this valley, but that he could not prevail on the natives to shew him where it was. I have sent the Doctor a copy of the above extract.”

Remarks on the Serrature of the Middle Claw, and the irregular Denticulation of the Beak, in certain Birds. By W. MACGILLIVRAY, A. M., &c. Conservator of the Museum of the Royal College of Surgeons, &c. Communicated by the Author.

THE serrature of the middle claw of certain species of birds, is a circumstance which must have attracted the notice of every person accustomed to look somewhat minutely to birds. The results of my observation on this subject may be briefly stated as follows. In different birds, the claws are of various forms: sometimes nearly circular in their transverse section, and more or less curved, as in hawks and owls; sometimes flat and expanded, as in grebes; sometimes they have two small sharp margins, and sometimes one of the margins is enlarged. In all birds, the inner margin of the third or middle claw is larger than the outer, and that claw is more or less curved outwards. Claws with small margins, or such as are strong, with a thick margin, are never serrated, as in eagles, pheasants and geese. Claws which have the inner margin dilated, but rather strong, are sometimes undulated, not merely on the edge-line, but along the whole plane of the inner slope, as in some ducks and gulls. In the shearwater and some other birds, the margin, which is dilated, and rather thin, is undulated with irregular serratures. In the herons, in which the middle claw has a thin margin, the serrature is regular; but in the storks and Balearic crane, in which the claw is thicker, the margin is entire. In the genera

Carbo, Pelecanus, Sula, and Phaeton, the margin of the middle claw is thin and distinctly serrated. In the grebes, in which the claws are quite flat and round, the extremity of that of the middle toe is also serrated, or rather cut into by parallel lines, Lastly, In the genus Caprimulgus, in which the inner margin of the middle claw is extremely thin, so as to be quite flexible, that margin is regularly, beautifully, and deeply serrated, insomuch that it may be said to be pectinated; while in the intimately allied genus Podargus, the claws of which are of a different form, the margin is entire.

The serrature of these claws is not like that of the leaves of plants, or the teeth of a saw, but consists of short parallel cuts in the edge of the claw, not at right angles to the central line, but more or less oblique, and directed towards the base, somewhat like the barbs of a quill, parallel, and in contact at the edges. They are in general, but not always, equally distanced; and the thinner the claw is, the more regular they usually are. The serratures towards the end of the claw are more or less broken. Sometimes there is, in consequence, a large piece of the inner edge wanting, and sometimes, especially in very thin claws, as in those of the goatsuckers, the end of the claw is broken off. Such are the facts known to me on this subject.

When certain persons have observed a fact in structure, they are desirous of knowing its relation to function, and employ various methods for this purpose; but, on the whole, conjecture is the mode usually adopted, for observation is not suited to the genius of all who call themselves naturalists, and fancy is a ready solvent for all gordian knots in physiology. In the Journal of the Royal Institution of Great Britain, for October 1830, there is a paper on the Cleanliness of Animals, by Mr Rennie, in which he takes occasion to allude to the pectinated structure of the claw of the middle toe of the fern-owl or goatsucker. The following are his remarks in a condensed form.

The bird alluded to has the middle claw cut into serratures, like a saw or a short-toothed comb. White of Selborne seems to think this structure given for the purpose of enabling it to seize insects. Mr Dillon's observations lead him to suppose that the serratures are employed by the bird to comb its whiskMr Swainson thinks that the fact of an American group

ers.

of the same birds, which have no whiskers to comb, and an Australian group, which have whiskers, but no serratures on the claws, is discordant with Mr Dillon's opinion. Wilson, the American ornithologist, in describing the Whip-poor-will, says the pectinated middle claw is probably employed as a comb, to rid the plumage of its head of vermin. He makes a similar remark with reference to the Chuck-will's-widow. "Considering the utility of such an instrument," says Mr Rennie, "we may wonder, perhaps, that besides the herons, no other birds are similarly provided for attacking those troublesome insects, which often seriously injure the vigour and health of the animal infested, and sometimes even occasion death." He then proceeds to relate a case of a swallow, which, being infested with vermin, "seemed instinctively courting human aid," and allowed him to free it of its tormentors, after which it flew off joyfully to join its companions. The case is similar to one which occurred to Audubon. A hawk allowed itself to be caught and carried home, sat patiently on a perch until its portrait was leisurely finished, and then flew off in merry mood. In fact, it seemed instinctively desirous of being represented by the artist.

Observation and experiment can alone determine the use of an organ; but, on the subject in question, we are deficient in facts. Wilson says the Carolina Goatsucker is often employed in riding itself of vermin, by means of its pectinated claw, " at least, when in a state of captivity." But Audubon, who had better opportunities of observing that bird, professes entire ignorance of the use of the claw. Birds, however, which have no pectinated claw, may be seen, in freedom and in captivity, scratching their heads, often very assiduously, and thus the pectination is not at all essential to the purpose. In the deficiency of observed facts, we may sometimes have recourse to analogy and reflection; at least, the truth of an alleged or supposed fact, may sometimes be settled by means of them.

It is a fact that many birds are much infested by vermin, especially about the head. It is also a fact that, in general, these parasitic insects do not injure their patrons in a serious defor animals much infested by them, appear to perform all gree, their functions as well as other individuals of the same species less infested. When an animal becomes sickly, its vermin may

increase so as seriously to add to its disease, or vermin may become a disease, and injure or destroy the animal; but these are conjectures rather than facts. It is a fact, that birds. liable to be infested by vermin are quite unable to rid themselves of their tormentors, the latter enjoying almost perfect immunity, especially about the head, which, with others, is a reason why the head, and especially the anterior part of it, should be more densely peopled than the other parts of the body. It is asserted that gallinaceous and passerine birds wallow in dust for the purpose of ridding themselves of vermin. The reason is doubtful, although the fact is notorious; but it is certain that these birds have vermin, of which they do not succeed in ridding themselves by means of their bills or claws. If an active little bird, like a chaffinch or wren, be not able to wield its bill effectively, how much less chance has the spoonbill, the stork, the goose or the eagle! I have watched gannets as they sat on their nests, or roosted on the rocks, but I never saw one scratch its head, although these birds are sadly infested by insects, and have the middle toe serrated. But against the supposed use of the serrated claw in the goatsucker, the fact is decisive that birds at least as much infested by insects, such as the magpie, auk, and guillemot, have no comb. Besides, the claw in question is so constructed that it could not answer the purpose intended; for the serratures are close, and therefore could not act as a comb, or if the barbs could be introduced between them, they are so thin and delicate that a week's use would render the comb unserviceable. As to the seizing of insects, it being a fact not observed but supposed, it is only necessary to ask if herons, pelicans, and boobies catch insects, or fishes either, with their claws? Lastly, if the pectinated claw be used by the goatsucker for cleaning its whiskers, which become clogged with the scales of moths, why has not the cormorant whiskers to be cleaned, seeing it has the currycomb? In short, we know nothing about the matter; but one fact often throws light on another.

Thus it is a fact that the edges of the bill of the gannet, the booby, and the lesser booby, are irregularly serrated, sometimes deeply and indistinctly, especially in the latter species. The serratures have a regular direction, being inclined inwards or toward the base of the beak. Now, it is a fact, that until the