FINE ARTS.

Among the Portraits, those of Pickersgill take the highest stand. Next to him we may place Mr. Briggs, who has this year made good his claim to excellence in this more profitable branch of the profession-newed, and their hearts growing glad and gay as having already established it as an historical painter. Those of Sir M. A. Shee, notwithstanding his ancient fault of chalkiness, are worthy of high praise. That of Chantrey will not suffer by comparison with any in the Exhibition.

distinguished. The Old Harper in the back beyond any he has yet produced. The tinted

PROCEEDINGS OF SOCIETIES.

BRISTOL INSTITUTION.

We believe that few provincial cities can vie with Bristol in the efforts that have been there made towards improvement in science and the arts. We have had frequent opportunities of noticing the zeal of its members in procuring from the most unquestionable sources, information upon all topics that come within the plan of its leading institution. We publish with much pleasure the following lecture recently delivered in its hall by Dr. Riley-it is one of a series on Erpetology. After some observations on the order Saurians, the Doctor proceeds:—

"The genus crocodile is characterised by the scaly covering of its body, which forms ridges along the back: it has four feet, with five toes before and four behind, three toes on each foot being armed with nails; the feet are palmated; the tail is flattened on the sides, and has a dentated ridge on the upper margin. This genus contains three subgenera, the gavial, the crocodile, and the alligator; these will be described in the next lecture. They increase to a very large size in tropical climates, having been known to arrive at the length of thirty or even forty feet. They were regarded by the Egyptians with great reverence, on account of their use in preserving them from the incursions of the robbers of the Libyan desert. The Dutch, at the present time, fill the ditches round their forts in the East Indies with voracious animals, to prevent desertion from within and attacks from without.

"On examining the structure of the crocodile, we find it modified almost entirely for existing in water. Besides its palmated feet, the tail furnishes it with a very powerful means of propelling itself through this element. The opening into the nose is guarded by a contractile ligament which keeps it in general closed, and with a system of muscles to open it when required; by this means (which is similar to the apparatus connected with the claws in a cat's foot) the water is prevented from entering the air passages when the head is immersed in it. The opening from the mouth to the nose also, is so formed that the radimentary tongue acts as a valver in such a manner as to allow the animal to breathe whilst the mouth is full of water. We find none of these adaptations in the land lizards; in them the tail is round, and there is no palmation of the feet.

"In examining the osteology of the crocodile, we perceive that the head is very much elongated, and that the bones are formed of a number of pieces like those of the chelonians. The occipital bones consist of four pieces; the frontal at first of six, which afterwards become five, the two central parts being united into one, to afford greater strength to that part of the head, which is the most vulnerable part of the whole animal, the strength of the scales being sufficient in almost every part of its body to turn a musket-ball; for the same reason the two parietal bones are consolidated into one. The lachrymal bones, which in man form a small portion of the lachrymal canal, are here extended so as to fill a considerable part of the face; the nasal bones are also considerably elongated; but the principal part of the openJune.-VOL. XXXVI. NO. CXXXVIII.

ing into the nose is surrounded by the intermaxil-
lary bone, which is of very large size. The
formation of the teeth of the crocodile is worthy
of notice. As it feeds entirely upon animal food,
it is necessary that it should be well furnished
with the means of catching it. The front teeth of
the lower jaw, when the mouth is closed, shut
into a set of openings in the intermaxillary bone,
which forms part of the upper jaw, in such a
manner that nothing held in them can escape.
The teeth are hollow cones, and are constantly
being replaced with new ones, which grow up be
neath them. The lower jaw is composed of six
pieces on each side, a proper acquaintance with
which will be of material use to us in assigning to
the fossil genera their proper situations. They
are called the dental, the opercular, the angular,
the subangular, the articular, and the compliment-
ary bones. The neck is formed in such a manner
as to possess very great strength, but at the same
time scarcely any mobility; the transverse pro.
cesses are extended in form of a T, so as to pre-
vent lateral motion, and to afford more surface
for the attachment of muscles: the transverse
processes of the two superior vertebræ are de-
lanceolated and much elongated, which is a point
worth notice, with reference to the fossil genera.
The cervical vertebræ are seven in number, the
dorsal twelve, the lumbar five, the sacral two,
and the candal forty-two. The central portions of
these vertebræ are, in all the Saurians, round, and
separated from the other elements, affording a
ready means of distinguishing the fossil vertebræ
of the Saurians from those of other animals.
One of the great peculiarities of the crocodile is
its power of abdominal respiration when in the
water. It is furnished with an abdominal ster-
num, and seven pairs of cartilaginous ribs. By
means of two openings in the parietes of the abdo
men, the crocodile has the power of admitting the
water into the cavity, the lining of which has the
power of absorbing the air from the fluid. This
circumstance explains why the crocodile is so
much more active and powerful when in the wa-
ter than on land. Man has been defined to be a
species intermediate to those that follow him.
He is far superior to any other animal in the de-
velopement of his brain and nervous system; but
his locomotive organs are inferior to that of the
horse, his circulating system to that of many other
animals, and we perceive that even that degraded
animal the crocodile has a respiratory apparatus
in some respects superior to his own. These ab-
dominal ribs exist in a rudimentary state in the
white lines across the recti-muscles of most mam-
malia.

"These animals live in holes in the banks of rivers, and destroy their prey by holding it under water; they do not immediately eat it, but deposit it in a secret place until it is softened by decomposition. The female lays her eggs secretly, and afterwards watches them and takes charge of the young. There are sixteen species in the genus. They are classed under three subgenera, the gavial, the crocodile, and the alligator.

"The gavial is distinguished by the narrowness and length of its jaws; all the feet are palmated, and the skin rises into a dentated ridge on the posterior margin of the legs, forming a kind of semi-palmation; the tail is extremely long, and 2 L

the vertical ridge on it very strongly marked; the
temporal fosse are very large; the nasal bones
only extend half way down the face, and do not,
as in the crocodile, surround part of the opening
into the nose, which is here entirely formed by
the intermaxillary bones; the two lateral portions
of the lower jaw are joined together for some ex-
tent; and the dental and opercular bones are
greatly developed. The head is formed for cutting
the water with facility; and we see that by the struc-
ture of its organs of locomotion, its powers of pro-
gression are considerable. According to the law
of balancing of organs, noticed in the first lecture,
we find a deficiency of power in its organs of
offence as compared with those of the crocodile
and alligator; for the elongation of the jaws
throws the resistance to a considerable distance
from the power, and the force is therefore much
less advantageously applied, as far as regards
strength, than in those animals which have short
jaws, and the muscle inserted near the resistance.
This animal inhabits India, and abounds in the
Ganges. Ælian informs us that there were two
kinds of Ganges crocodile, the one cruel and the
other not so; by the first he probably meant the
common crocodile; and by the second, the gavial,
as from its want of strength it is less bold and fero-
cious than the former. Cuvier describes a second
species of gavial, the tenuirostris, from a specimen
in the Jardin des Plantes; it is not improbable,
however, that this is only a variety of the former.

"In the crocodile, the head is shorter than that of the gavial, but is still twice as long as it is broad. The posterior members only are palmated and furnished with serrated edges; the fourth tooth in the lower jaw passes into a groove in the upper jaw; (in the alligator this tooth passes into an opening of the jaw itself, giving it the power of holding it, with great firmness;) the temporal fossa is smaller than that of the gavial. There was not any separation of species of this genus until the French expedition to Egypt, which has been beforementioned as having much advanced the study of natural history. The crocodile of the Nile is the one which has been the oftenest and best described. The eyes are more distant than in the other species, and there is no crest or ele vation between them. It has six plates on the neck, and six very regular rows of rectangular plates on the back. Its colour is a dark green approaching to bronze, but much lighter under the abdomen. It is called in Egypt, champses.

"The crocodiles of the Nile are now found only in Upper Egypt, and are not lethargic, as they were formerly said to be, during four months of the year, the climate being sufficiently warm to keep them constantly in an active state. They frequently attain the length of thirty feet, or even more; they have a strong odour of musk, and their flesh is eaten by the negroes. In some parts of Ancient Egypt, the crocodile was held in great respect, and even worshipped; whilst in others every means was employed to destroy them; we have already stated the use of which they were to the Egyptians in preventing the Libyan and Arabian robbers from crossing their rivers. The same species of crocodile is found in other rivers of Africa, particularly the Gambia and Senegal, and it is remarked that the farther inland we proceed, the greater is the size of the crocodiles found there. The hippopotamus is its most formidable enemy, and conflicts frequently arise be

tween them, the crocodile being generally worsted. Great numbers of crocodiles' eggs are destroyed by the ichneumon, and many of the young ones become the prey of birds, tortoises, &c.

"Herodotus wrote much respecting the crocodile of Egypt, though his account has been generally supposed to be very erroneous; but the observations made by Geoffroy de St. Hilaire, and the information which he acquired from the Egyptian fishermen, tend very much to confirm it. It appears that, at the time of Herodotus, the crocodile inhabited Lower Egypt; and it is, therefore, not unlikely that the hybernation mentioned by him really took place, though it is not the case at present. The time during which it can remain under water is stated to be ten minutes, and it frequently is not seen to rise to the surface at the expiration of that time, as when it does not wish to be observed, it merely elevates its head sufficiently to obtain a supply of air through the aperture into the nose. One of the assertions of Herodotus which has been most ridiculed is, that the wren is in the habit of entering the crocodile's mouth, and removing from it the leeches adherent to the palate. As there are no leeches in the Nile, and as the wren does not inhabit Egypt, his account was considered completely fabulous; but it appears from the statement of the Egyptian fishermen at the present time, that the crocodile is much annoyed by gnats, which suck the blood from the inside of its mouth, and that a species of plover relieves it by entering its mouth when asleep, and removing them. If, then, we translated the word Toxiλos plover, instead of wren, and ẞdeλλ¤ gnat, instead of leech, we shall find the account of Herodotus to be perfectly correct. When the crocodile comes out of the water, he turns his head to the wind, and holds his mouth open for a considerable time, as if by this means to make up for the deficiency of his respiration in the air, as noticed in the last lecture. From the veneration in which the crocodile was held in many parts of Egypt, it is not surprising that we find many mummies of this animal. It is not certain whether the species which was domesticated, as it were, in their temples, was or not the common crocodile of the Nile. From an examination of many embalmed specimens, Mr. Geoffroy de St. Hilaire has made it a separate species, calling it the C. suchis. He says that the head is longer and flatter; that the colour is different; and that the jaws are much less strong; besides which, its length seldom exceeded five feet. The C. acutus of St. Domingo has six plates fewer than the species we have mentioned. It has the power of bending its tail so as to make it touch the sides of its body.

"After mentioning five other species of crocodile, which present nothing very remarkable to distinguish them, Dr. R. proceeded to the alligator, which is characterised by the wideness of its head in proportion to its length; the fourth tooth in the lower jaw passes through an aperture in the upper jaw; the temporal fosse are small; the feet are only semi-palmated, and there is no ridge on the posterior legs. The pike-nosed alligator, (A. lucius,) which is distinguished by the four plates on the back of his neck, inhabits North America as far as 32 deg. north of the Equator. It hybernates during the winter, and lives usually on insects and fishes, though occasionally it attacks large animals. It is stated

by Bose, who paid much attention to its habits, that if a white man and a negro were presented to it at the same time, it would prefer the latter. He also mentions a curious stratagem of the dogs which live near the rivers where the alligators

abound. When they wish to drink, they go to the water and bark; this attracts the alligators to the spot; the dog immediately runs as he can to some

distant part of the river, where he has time to

drink before the alligators can come up with him. The A. sclerops is distinguished by a mark round the eyes, resembling a pair of spectacles, whence its name, and by the narrowing of the jaw. The distinction between the other species is quite arbitrary; they are named palpebrosus, "With respect to the extinct species of this

trigonatus, and cuvierianas.

genus, we may remark, that the older the strata in which remains of them are found, the more these remains differ from the animals at present existing. The first fossil Saurian animal of which we have any account, was described by Dr. Stukeley, in the " Philosophical Transactions" for 1718. It was found in the oolite, near Newark, and was at first supposed to have been a human skeleton. Dr. Stukeley considered it to be either a crocodile or a porpoise, though the presence of the pelvis should have made him perceive that it could not be the latter. M. Conybeare has since

determined it to be the Plesiosaurus. In 1798 a fossil Saurian was discovered in the lias on the shore near Whitby. The length of the spine was nine feet, and that of the head two feet nine inches. The form of its head was very similar to that of the gavial, to which it seemed more closely allied than to the other genera. The Crocodilus priscus may in the same manner be considered as an extinct species of gavial, though it differs from it in several important particulars,

having ten more vertebræ in the tail, and the femur being twice as long as the tibia, whilst in the gavial it is of the same length. It was found in the Jura limestone (an oolitic formation.) The teleosaurus affords, in some degree, an illustration of Lamarck's theory of the progressive elevation of the forms of the lower animals, until they arrive at a higher state. It resembles the gavial in many respects; but the developement of the organ of sinell shows an advance towards the conformation of the mammalia. The steneosaurus is found in the oolite near Honfleur. It may be considered an extinct species of gavial. Many remains of the crocodile have been found in the iron-sand of Tilgate Forest, and in the chalk formation."

ROYAL COLLEGE OF PHYSICIANS.

A paper on the subject of diseases reckoned contagious, more especially in connexion with the prevalent epidemic, from the pen of Dr. Heberden, was read by Dr. Hawkins, at a recent meeting. The author appeared to lean to the side of contagion; but in clear and unbiassed language, he reviewed the arguments and facts urged by the supporters of contagion and non-contagion. The course of no disease, he observed, had been traced with more certainty than that of Cholera for the last fifteen years. Was it to be supposed that its ravages were occasioned by a certain

state of the atmosphere? If so, why had it
travelled so slowly? Influenza, dependent
on that cause, was marked by an opposite
character-it travelled swiftly. On the sub-
ject of predisposition, the author observed,
it was not enough that the seed should be
vigorous, the temperature of the atmosphere
suitable; the soil also must be adapted to
circumstances: clearly implying, we think,
that if the system be not made a fit recep-
tacle for a certain class of diseases by intem-
perance, privation, or inattention to cleanly
habits, attacks of this kind will be less fre-
quent and virulent, although aided by pecu-
liarity of sky or climate. On infection some
curious remarks were made: ex. gr. the in-
habitants of a part of the Hebrides, on the
authority of the clergyman, it was stated,
always "caught a cold," as the phrase is,
on the arrival of a stranger amongst them!
Again, it was well known that individuals
visiting certain parts of the globe, were
more liable to peculiar diseases than the in-
habitants. Was this owing to insects float-
ing invisibly in the air, who, like epicures,
preferred exotics? It appeared, that amongst
those who considered Cholera as contagious
was Sir Thomas Monro, who fell a victim to
its malignant attacks: surrounded by his
friends, while on his death-bed, he warned
them of the consequences of their kind at-
tention, and called upon them to leave him
to himself. After some remarks on the
analogy of contagion in small-pox and that
in Cholera, where some are susceptible
and others non-susceptible-a circumstance
which might be adduced, by those who were
so inclined, as a refutation of the doctrine
of contagion - the paper concluded by a
few hints on disinfection and prevention;
the former, boiling in water, or exposing to
a strong heat, the suspected article; the lat-
ter, natural good health and temperance.

ROYAL SOCIETY OF LITERATURE.

An article, entitled " Etruria," was read from a manuscript by Sir W. Gell, on Roman topography; in which the author enters at considerable length into a discussion upon the origin of the nations inhabiting that part of the Italian peninsula; their connexion with the Pelasgi and the Celts; the arrival of colonies of Tyrrhenians, or Lydians, from Asia-Minor, and the migration of Siculi, or Tyrrhene Pelasgians, to Athens, where, according to Pausanias, they were employed in constructing part of the wall of the Acropolis. The author endeavours to explain and to reconcile the various accounts given of the origin of the Etrurians by Herodotus, and the several writers that have followed his opinion (who derive them from the continent of Asia), on the one side, and of Dionysius of Halicarnassus on the other, who describes them as Greeks. Some simi