Diceras arretina (Lam.), the type from Mont Salève, and the neighbourhood of St. Mihiel, and Diceras sinistra (Desh.) from the superior oolite in the vicinity of the last named place. Rang would place next to Diceras the genus Caprina of D'Orbigny père; and he is of opinion that if that zoologist would publish his discoveries on these interesting shells, the genus would be generally adopted. The genus Ichthyosarcolite, which has been always classed with the cephalopods, might, he thinks, belong to a bivalve approximating Caprina. Deshayes, he says, communicated to him the same idea. But the last named author does not notice the genus when treating of Diceras in the last edition of Lamarck. CHAMEDO'REA, a genus of palms, also called Nunnezharia and Nunnezia. They are small reed-like plants, with ringed shoots. Their leaves are either cleft or pinnated. The inflorescence is sessile within the sheaths of the leaves, and branched in an irregular manner; the| spathes are membranous. The flowers are yellow and dicecious, without bracts, which is a remarkable circumstance. In the males the calyx is cup-shaped and three-parted; the petals three, and the stamens six. In the females the calyx and petals are the same; the ovary three-celled; the berry one-seeded; the albumen even; and the embryo lateral. These are palms of humble growth, receding in that respect from the general character of the order, and approximating to herbaceous Endogens, or to Bamboos. Ch. fragrans, the Chutasslium of the Peruvians, is a plant with a stem about a man's height, and so fragrant as to fill the groves with its perfume in the months of August, September, and October. CHAMEPE'LIA. [DOVES.] CHAME ROPS, a genus of palm trees, in which is comprehended the most northern species of those remarkable vegetable productions whose home is so frequently in the tropics. It is characterized by its flabelliform leaves, polygamous flowers, which are sometimes even dioecious, and triple monospermous drupes, with ruminated albumen. Chamaerops humilis, the European species, grows in hothouses to the height of fifteen feet; but in Spain and Barbary it is not more than four or five feet high, and in Italy it is much dwarfer. It is common upon the hills near Algiers; it occurs in many places in the southern parts of Italy; and reaches its northern limits in the vicinity of Nice. The trunk of this plant is five or six inches in diameter, and closely covered with triangular hard scales, which are the bases of the antient leaves. The new leaves grow in a tuft at the top of the stem, and have smooth flat stalks, with rigid spines proceeding from the edge; the blade is deeply palmate, with from twelve to fifteen narrow swordshaped divisions, which are slightly glaucous and downy. The flowers grow within compressed spathes, which are downy at the edge, and from six to eight inches long, and upon a short compressed spadix, which is closely covered over. The drupes are blackish-brown, and round, with a fibrous dry spongy flesh. The young underground parts of the stem, and the young roots, are said by Desfontaines to be eatable. CHAMELE DON PROCUMBENS, a beautiful little alpine bush, formerly referred to Azalea, from which it differs essentially both in habit and botanical characters. It is a small evergreen creeping shrub, found on the mountains of Europe and North America. The leaves are leathery, shining, turned back at their edge, and about half an inch long. The flowers are minute, and grow in terminal umbels of a light flesh colour. The calyx is fiveparted; the corolla campanulate and regularly five-cleft, the anthers rounded and opening longitudinally. It is occasionally seen in gardens, but it is rather impatient of cul tivation. CHAMELEON, a constellation near the South Pole, formed by Bayer. [BAYER.] The stars are as follows: Chamaerops humilis.] CHAMESAURA. [CHALCIDES. CHIROTES. SKPS.] From some recent experiments, it appears that the parabolic chamber is preferable to the other kinds; and if we suppose that the inflammation of the powder were to commence at the focus, the superiority of effect might be conceived to be owing to that property of this curve by which the rays from the focus, after striking the surface, are reflected in lines parallel to the axis. CHAMEZA (Zoology), a genus of the family Meru- | are said to have been written by him while he stood behind lida, Vigors. [MERULIDE.] the counter. Before the completion of the work however, CHAMBER, a recess formed at the lower extremity of and probably after he had made arrangements with the the bore of a gun, howitzer, or mortar, and in the direction bookseller who published it, he left Mr. Senex, and took of the axis, in order to receive the charge of powder by chambers in Gray's Inn. The first edition of the Cyclo which the shot or shell is to be projected. It is made of a pædia appeared in two vols. fol. in 1728, and was very cylindrical, hemispherical, or parabolical form, and its mag-favourably received. It was published by subscription, the nitude is such as to allow it to contain the quantity of price of each copy being four guineas. Immediately after, powder constituting the charge, but its diameter is less than the author was made a Fellow of the Royal Society. A that of the bore, in order that the fired gunpowder may act second edition of the work appeared in 1738, and a third in more intensely upon the projectile in the line of its direction. 1739. Mr. Chambers was also one of the writers in the The Gomer chamber, so called from the name of the Literary Magazine,' an analytical review of new works, inventor, is made in the form of a frustum of a cone, ter- which was begun in 1735, and continued for some years. minating with a concave hemisphere at the smaller part, He was likewise associated with Mr. Martyn, the botanical which is the extremity of the chamber, and the greater cir- professor at Cambridge, in translating and abridging the cumference coinciding with that of the bore. The shot or Philosophical History and Memoirs of the Royal Academy shell, being placed in close contact with the conical part of of Sciences at Paris,' which appeared in five vols. 8vo, in a chamber of this kind, thus becomes subject to the whole 1742. This task he executed very ill. The only other lite force of the elastic fluid. rary work which has been attributed to him is a translation from the French of a quarto volume, entitled 'The Jesuits' Perspective.' He lived to the last the life of a recluse and a hard student, reading and writing from morning to night almost without intermission. A person who was his amanuensis for six years is said to have related that he transcribed for him, and took down from his dictation in that space of time, not less than twenty large folio volumes, containing as much matter as, if it had been printed, would have made thirty such volumes as those of his Cyclopædia. He died on the 18th May, 1740, at Canonbury House, Islington, and was buried in Westminster Abbey, under a short Latin inscription of his own composition. A fourth edition of his Cyclopædia appeared in 1741, and a fifth in 1746. To the sixth edition, which was brought out in 1750, were added two supplementary volumes, which were compiled by Sir John Hill, the botanist, and George Lewis Scott, the mathematician. These, along with much new matter, were incorporated with the original work in a seventh edition, which began to be published in numbers under the superintendence of the late Dr. Abraham Rees in 1778, and was completed in four vols. folio, in 1785. Chambers's work is also avowedly the basis of the greatly more extended Cyclopædia in the conduct of which Dr. Rees afterwards engaged, and which he lived to complete in forty-five vols. 4to. (London, 1802-1819). Indeed it may be said to have originated all the modern Cyclopædias, both in the English and in other European languages. It was early translated both into French and Italian. In the prospectus of the great French Encyclopédie of Diderot and D'Alembert (afterwards incorporated in the Discours Préliminaire), it is admitted that Chambers's plan is excellent, though the execution of the work is very indifferent. The writers add, that it possibly never would have appeared at all, if there had not previously existed in the French language works from which Chambers drew, without measure and without choice, the greatest part of the matter which composed his dictionary. CHAMBER, IMPERIAL. [IMPERIAL CHAMBER.] CHAMBERLAIN, custos cubiculi, or cubicularius, keeper of the chamber, was an officer of great antiquity, and occurs among many of the earliest nations. In those of the East, as appears from the description of persons employed, chamberlain and eunuch were often synonymous. In the Anglo-Saxon times, in England, the chamberlain appears to have had the name of Camerarius, and had the keeping of the king's treasure (Ealred, in vit. S. Edw. Confess., c. ii. p. 9), by which name this officer also occurs in the Domesday Survey. The office of lord great chamberlain of England was once of the highest dignity, and was held in grand serjeanty from the second year of King Henry I. by the family of De Vere, from whom it passed, by a female heir, to the family of Bertie. By the statute of precedency, 31 Hen. VIII., the great chamberlain's place was next to that of the lord privy seal. In 1714, the Marquess of Lindsay, then hereditary great chamberlain of England, having been raised to the dukedom of Ancaster, surrendered this precedency for himself and his heirs, except only when he or they should be in the actual execution of the duties of the said office, in attending the person of the king or queen, or introducing a peer into the House of Lords. This surrender was confirmed by Stat. 1, Geo. I. c. 3. The duties which now devolve upon the great chamberlain are, the dressing and attending on the king at his coronation; the care of the antient Palace of Westminster; the provision of furniture for the Houses of Parliament, and for Westminster Hall, when used on great occasions; and attendance upon peers at their creation, and upon bishops when they perform their homage. On the death of Robert, the last duke of Ancaster but one, in 1779, the office of hereditary great chamberlain descended to his two sisters, Priscilla Lady Willoughby de Eresby, and Georgiana Charlotte Marchioness Cholmondeley, by whom Sir Peter Burrell, the husband of Lady Willoughby (afterwards Lord Gwydir), was first appointed to perform the duties; and subsequently, in 1821, his son the present Lord Gwydir, who still holds the office of deputy great chamberlain of England. The office of lord chamberlain of the king's household is one which is held during his majesty's pleasure only; and the holder of it is usually changed with the administration. He has the control of all parts of the household, which are not under the direction of the lord steward, the groom of the stole, or the master of the horse; the king's chaplains, physicians, surgeons, &c., as well the royal tradesmen, are by his appointment; the companies of actors at the royal theatres, as part of the household, are under his regulation, and be is also the licenser of plays. CHAMBERS, SIR WILLIAM, is said to have derived his descent from a Scotch family of the name of Chalmers, who were barons of Tartas in France. He was born however in 1726, at Stockholm, in Sweden; whither his grandfather, an eminent merchant, had proceeded some time before, to prosecute certain claims he had upon the government of that country. At two years of age he was brought to England, and put to school at Ripon in Yorkshire. We next read of his making a voyage to China as supercargo, in the service of the Swedish East India Company. This must have been when he was a very young man, for at the age of eighteen he is said to have settled in London, and taken up the profession of an architect and draughtsman. In these capacities, having no formidable rivalry to encounter, he soon obtained considerable reputation. At length he was introduced to the earl of Bute, and by his influence appointed drawing-master to the young Prince of Wales, afterwards George III. Soon after the accession of that king, he was employed to lay out the royal gardens at Kew. In this task he displayed without restraint that predilection for the Chinese style, both of gardening and archi CHAMBERS, EPHRAIM, was born at Kendal in the latter part of the seventeenth century. His father was a small freeholder in Westmoreland, in respectable circum-tecture, of which he had already given intimation in a work, stances. Ephraim, his eldest son, was bound apprentice to a mechanical trade in London. Eventually he became ap. prentice to Mr. Senex, the globe-maker; and it was while in his shop that he conceived the design of the Cyclopædia which has chiefly preserved his name. Some of the articles entitled Designs for Chinese Buildings,' published in 1759. 塩 for the Earl of Besborough, and by various other buildings, obtained much reputation and employment as an architect. In 1771 he was made a knight of the Swedish order of the Polar Star. In 1772 he published his Dissertation on Oriental Gardening.' This is another vindication of Chinese tastes and fashions, and is memorable as having exposed the author to the satiric lash of the poet Mason; to the first part of whose English Garden,' published immediately before, it was suspected to be intended as a sort of answer and confutation. The piece in which Mason took his revenge (if indeed he was the author, which he never acknowledged) was the famous Heroic Epistle to Sir William Chambers, Knight, Comptroller General of his Majesty's Works, and author of a late Dissertation on Oriental Gardening; enriched with explanatory Notes, chiefly extracted from that elaborate performance. This production appeared in 1773, and was followed in 1774 by a short continuation, under the title of An Heroic Postscript. The satire, however, does not seem to have injured its object in any essential respect. In 1775 Sir William was appointed to superintend the rebuilding of Somerset House, which is his best work. In 1791 he published his Treatise on Civil Architecture, of which two new editions, one by Joseph Gwilt, F.S.A., the other by an anonymous editor, appeared in 1824. Each contains considerable additions to the original work. Sir William died on the 8th of March, 1796, leaving a large fortune. As an architect, although his taste was fantastic, he frequently showed considerable ingenuity, and also displayed a certain grandeur in his designs. His staircases in particular used to be much admired. In the time of Sir W. Chambers, pure Greek architecture was only beginning to be known in England, and its introduction was at first not much favoured. The recent indiscriminate adoption of Greek models for public buildings in London has filled the metropolis with structures totally unsuited in external form to improve the appearance of a large city, and often ill adapted in their internal arrangements to the purposes for which they are designed. Instead of large masses and lofty buildings, the streets of London are crowded with mean porticoes and pigmy pillars, attached to edifices of so little elevation, and so much cut up mo small parts, as to lose by comparison with many of the adjoining houses. The street-front of Somerset I' se is in all respects better adapted to a great city than the Greek models which are now generally adopted. After Somerset House, among Chambers's most successful efforts, are the mansion which he built for the marquis of Abercorn at Duddingstone, near Edinburgh, and Milton Abbey in Dorsetshire, which he built in the Gothic style for Lord Dorchester. CHAMBE'RY, the capital of the province called Savoy Proper, is also the most considerable town in all Savoy, and the residence of the military governor of that Duchy, and of the senate or high court of justice for all its provinces. [SAVOY.] It lies, at an elevation of 930 ft. above the sea, in a fine valley, between two ridges which run N. W. and S. E., from the Rhone to the Isère, and may be considered as lower offsets of the Alps. The valley is watered by the river Leisse which falls into the pretty lake of Bourget, eight miles N.W. of Chambery. The valley from Bourget to Montmélian is about eighteen miles long and three broad. It abounds with vines, and the lower part is rich in pastures, but is subject to sudden inundations from the swelling of the mountain streams. The climate is mild, being sheltered from the N. winds. Chambery has a royal college, kept by the Jesuits an academy of sciences, called the Academy of Savoy, which publishes its memoirs; a society of agriculture and cou..merce; a public library, with a cabinet of natural history, and a school of drawing. There are many hospitals, houses for refuge, and other charitable institutions; several of which were founded by a native, General de Boigne, who, after an adventurous career in India in the last century, returned home with a large fortune, of which he devoted several millions of franes to improve his native city. He died a few years ago at his residence of Buisson Rond, near Chambery. The churches of Chambery have some good paintings. The population of the town and suburbs is about 11,000. (Calendario Sardo.) Many families of the nobility of Savoy, some of them very antient, reside in this town. The people of Chambery speak remarkably good French, but the country people have a patois which is a dialect of the Romance language. Provisions are cheap, which is generally the case in Savoy, where incomes are very moderate. Many beggars, especially of the class of country people, are seen in the streets of Chambery. Amad us V. was the first duke of Savoy who established his residence here. town has p oduced many distinguished men; among others, the Abbé de St. Réal, Vaugelas, Albanis Beaumont, known for his travels in the Alps; the painters Berengier and Berger; and the two Counts de Maistre, Xavier and Joseph, well-known in contemporary literature. (Bertolotti, Viaggio in Saroja.) CHAMBORD. [LOIR ET CHER.] CHAMECK. [ATELES. Species 8 ] This CHAMELEONS, CHAMELEON-TRIBE, CHAMELEONIDA (Zoology), the name for a well defined family of Saurians (lizard-like reptiles), whose differential and essential characters may be summed up as existing in the form of their feet, the toes of which are joined or bound up together in two packets or bundles opposed to each otherin their shagreen like skin-in their prehensile tail-and in their extensile and retractile vermiform tongue. Organization, Skeleton. The more striking peculiarities consist in the elevated and pyramidal form of the occipul. the absence of a true sternum, and in certain apophyses of the vertebral column, especially about the tail, where they are placed en chevron, so as to leave at their base a space where the caudal artery, a prolongation of the pelvic, is protected somewhat in the same way as the spinal chord is by the bony case above it, when the prehensile tail would otherwise subject it to pressure in grasping boughs of trees or other solid bodies with its lower surface. The transverse apophyses of the tail are but little developed. The glenoïd cavity is supported upon a short pedicle. The majority of saurians have eight cervical vertebræ, but the chameleon have only five. The first ribs are joined to the mesial line, which performs the office of a sternum, and the following ribs are united to each other by their cartilaginous prolongations towards the mesial line of the belly, so as to protect the abdomen by an entire bony circle. There are, as Schneider has observed, but two shoulder-bones, of which the coracoïd is very small, the clavicle being entirely absent. Cuvier remarked the singular disposition of the wrist. The two carpal bones which come next to those of the fore-arin are articulated upon one large central picce, which receives the five bones which correspond to the netacarpal, three of these being for the external toes and two for the internal, thus forming two oppo-able prel.ensile instruments, the two bundles being bound up in the integuinents and skin to the very claws. In the pelvis, the ilia are long and slender and directed towards the sacrum. with which they partially unite, but are molonged by a cartilage. The hind as well as the fore toes are five, and disposed in the same manner as those of the anterior extremities. The trunk, which has a compressed appearance, is moun ed high on the legs, forming an exception to the majority of reptiles, whose belly touches the ground. [Skull of Chamæleo bifidus.] Organs of respiration.-Cuvier observes that their lung is so large that, when it is filled with air, it imparts a trans parency to the body, which made the antients say that it ined upon air, and he inclined to think that to its size the chameleon owed the property of changing its colour: but with regard to this last speculation he was in error, as we shall presently see. There is not much difference between the esophagus and stomach, which latter is small and bent back upon itself. There is no true pylorus, although there exists, at the point where it should be, a sort of contraction in the membranes, which are there thickened. Organs of Sense. Touch.-On the under surface of the tail and toes are granulated papillæ, probably for the purpose of conveying to the sensorium the nature of the body grasped. The tongue must have a considerable share of the sense of touch; whether it has any high perception of that of tuste may be doubted. Smell.-Most probably not acute; the external orifices of the nostrils are more lateral, and consequently wider apart than in most of the other saurians. Hearing.-There is no visible external ear, but an internal cavity not much developed in the Lones of the sides of the skull, communicating with the throat, and covered externally by the common integuments. Sight.The eyes of the chameleon are remarkable objects; large, projecting, and almost entirely covered with the shagreenlike skin, with the exception of a small aperture opposite to the pupil: their motions are completely independent of each other. It adds to the strange and grotesque appearance of this creature, to see it roll one of its eye-globes backward, while the other is directed forwards, as if making two dstinct surveys at one time. Its sight must be acute, from the unerring certainty with which it marks and strikes its prey. Keproduction.-By means of eggs, which are numerous at each deposit, oval, and enveloped in a white, tough, parcnment-like skin. Hubits, &c.-The chameleons spend their lives in trees, for clinging to the branches of which their organization is admirably adapted. There they lie in wait for the insects which may come within their reach; and it is highly probable that, in such situations, their faculty of changing their colour becomes highly important in aiding them to conceal themselves. Of this faculty, concerning which so much has been written and said, we shall presently treat. The powers of abstinence possessed by this singular race are very great, and hence most probably arose the old fable of their living on air, which was for a long time considered to be the cha meleon's dish. We kept one for upwards of six weeks, and during all that time it never, as far as we could observe, took any sustenance, though meal-worms, and other insects were procured for it. Notwithstanding this fast, it did not appear to fall away much. It would fix itself by the feet and tail to the bars of the fender and there remain motionless, apparently enjoying the warmth of the fire for hours together. Its motions were excessively slow. It was a female, and died after laying a great number of eggs. Hasselquist describes one, that he kept for near a month, as climbing up and down the bars of its cage in a very lively manner. That the chameleon was known to the antients there is no doubt. It was the xauaidiwr of the Greeks and the chumæleo of the Latins. Aristotle's history of the animal proves the acute observation of that great zoologist, for he notices the peculiarities of the animal, the absence of a sternum, the disposition of the ribs, the mechanism of the tail, the motion of the eyes, the toes bound up in opposable bundles, &c. &c., though he is not entirely correct in some points. (Hist. Anim., book 2, ch. xi.) Pliny (Hist. Nal., lib. viii., c. 33) mentions it, but his account is for the most part a compilation from Aristotle. Organs of nutrition and digestion.-The teeth, as in the great majority of saurians, have no true roots: their crowns, which are trilobated *, seem to be soldered as it were upon the edge of the upper border of a groove hollowed in the taaxillary bone: they are connected to the osseous portion and also to each other, so as to present the appearance of an enamelled and denticulated portion of the edge of the bone. But it is the vermiform extensile and retractile tongue which is the chief organ for taking the insects on which the chameleon lives. By a curious mechanism, of which the os hyoides (tongue-bone) is a principal agent, the chameleon can protrude this cylindrical tongue, which is terminated by a dilated and somewhat tubular tip covered with a glutinous secretion, from the sheath at the lower part of the mouth, where the whole of the tongue, with the exception of the dilated tip, remains when at rest, to the length of six inches. When the chameleon is about to seize an insect it rolls round its extraordinary eyeballs so as to bring them to bear on the devoted object; as soon as it arrives within range of the tongue that organ is projected with unerring precision and returns into the mouth with the prey adhering to the viscous tip. Some writers speak of the wonderful celerity with which this feat is performed, and it cer-Zoography,' gives the following translation of the account tainly forms a strong contrast to the other almost ridiculously slow motions of the animal. We have never seen chameleons take a fly, but we have often seen them catch meal-worms; and the operation, though comparatively rapid, was not remarkable for its quickness, but done with an air of deliberation, and so that the projection and retraction of the tongue could be very distinctly followed with the eye. [Chameleon taking his prey.] Power of changing colour.- Passing by the earlier statements of those who have written on the subject, we shall commence with the details of modern times. Wood, in his given by the French academicians of this phenomenon: The colour of all the eminences of our chameleon when it was at rest, in the shade, and had continued a long time undisturbed, was a bluish grey, except under the feet, where it was white inclining to yellow; and the intervals of the granules of the skin were of a pale and yellowish red. This grey, which coloured all the parts exposed to the light, changed when in the sun; and all the places of its body which were illuminated, instead of their bluish colour, became of a brownish grey, inclining to minime. The rest of the skin which was not illuminated by the sun changed its grey into several brisk and shining colours, forming spots about half a finger's breadth, reaching from the crest of the spine to the middle of the back; others appeared on the ribs, fore legs, and tail. All these spots were of an Isabella colour, through the mixture of a pale yellow with which the granules were tinged, and of a bright red, which is the colour of the bottom of the skin which is visible between the granules; the rest of the skin not enlightened by the sun, and which was of a paler grey than ordinary, resembled a cloth made of mixed wool; some of the granules being greenish, others of a minime grey, and others of the usual bluish grey, the ground remaining as before. When the sun did not shine, the first grey appeared again by little and little, and spread itself all over the body, except under the feet, which continued of the same colour, but a little browner; and when, being in this state, some of the company handled it, there immediately appeared on its shoulders and fore legs several very blackish spots, about the size of a finger nail, and which did not take place when it was handled by those who usually took care of it. Sometimes it was marked with brown spots, which inclined towards green. We afterwards wrapped it up in a linen cloth, where having been two or three minutes, we took it out whitish; but not so white as that of which Aldrovandus speaks, which was not to be distinguished from the linen on which it was laid. Ours, which had only changed its ordinary grey into a pale one, after having kept this colour some time, lost it insensibly. This experiment made us question the truth of the chameleon's taking all colours but white, as Theophrastus and Plutarch report; for ours seemed to have such a disposition to retain this colour, that it grew pale every night, and when dead it had more white than any other colour; nor did we find that it changed colour all over the body as Arisotle reports; for when it takes other colours than grey, and isguises itself to appear in masquerade, as Elian pleahantly says, it covers only certain parts of the body with them. Lastly, to conclude the experiments relative to the colours which the chameleon can take, it was laid on substances of various colours and wrapped up therein; but it ook not them as it had done the white, and it took that nly the first time the experiment was made, though it was epeated several times on different days. In making these experiments, we observed that there were a great many places of its skin which grew brown, but very little at a time: to be certain of which, we marked with small specks of ink those granules which to us appeared whitest in its pale state, and we always found that when it grew brownest and its skin spotted, those grains which we had marked were always less brown than the rest,' The details of this experiment should be borne in mind when reading the interesting memoir of Mr. Edwards, to which the reader is afterwards referred. Hasselquist thought that the changes of colour depended on a kind of disease, more especially a sort of jaundice to which the animal was subject, particularly when it was put in a rage. M. d'Obsonville thought that he had discovered the secret in the blood. He considered that the change of colour depended upon a mixture of blue and yellow, whence the different shades of green were derived, and these colours he obtains from the blood and the blood-vessels. Thus he says that the blood is of a violet blue, and will retain its colour on linen or paper for some minutes if previously steeped in a solution of alum, and that the coats of the vessels are yellow both in their trunks and branches; consequently, he argues, the mixture of the two will produce green. He further traces the change of colour to the passions of the animal. When, he observes, a healthy chameleon is provoked, the circulation is accelerated, the vessels that are spread over the skin are distended, and a superficial blue green colour is produced. When, on the contrary, the animal is imprisoned, impoverished, and deprived of free air, the circulation becomes languid, the vessels are not filled, the colour of their coats prevails, and the chameleon changes to a yellow green, which lasts during its confinement. Mr. Barrow (African Travels) declares, that previously to the chameleon's assuming a change of colour, it makes a long inspiration, the body swelling out to twice its usual size, and as this inflation subsides, the change of colour gradually takes place; the only permanent marks being two small dark lines passing along the sides. Mr. Wood conceives from this account, that the animal is principally indebted for these varied tints to the influence of oxygen. Mr. Spittal also regards these changes as connected with the state of the lungs; and Mr. Houston considers this phenomenon as dependent on the turgesency of the skin. Not to go farther into the numerous treatises and memoirs which have been published on this intricate subject, without arriving at a just conclusion, we refer to the conclusion of the able and interesting paper of Mr. Milne Edwards, for whose acuteness the solution of this puzzling phenomenon was reserved. It appeared in the Annales des Sciences Naturelles for January, 1834, and is translated in the seventeenth volume of the Edinburgh New Philosophical Journal, p. 313. The steps by which he first overthrew the received theories on the subject, and then arrived at a knowledge of the cause of the change of colour, are so clearly stated, that we recommend our readers to study the whole memoir, the results of which only we give here. 1. That the change in the colour of chameleons does not depend essentially either on the more or less considerable swelling of their bo lies, or the changes which might hence result to the condition of their blood or circulation; nor does it depend on the greater or less distance which may exist between the several cutaneous tubercles; although it is not to be denied that these circumstances probably exercise some influence upon the phenomenon. 2. That there exists in the skin of these animals two layers of membranous pigment, placed the one above the other, but disposed in such a way as to appear simultaneously under the cuticle, and sometimes in such a manner that the one may hide the other. 3. That every thing remarkable in the changes of colour that manifest themselves in the chameleon may be explained by the appearance of the pigment of the deeper layer to an extent more or less considerable, in the midst of the pigment of the superficial layer; or from its disappearance beneath this layer. 4. That these displacements of the deeper pigment do in reality occur; and it is a probable consequence that the chameleon's colour changes during life, and may continue to change even after death. 5. That there exists a close analogy between the mechanism by the help of which the changes of colour appear to take place in these reptiles, and that which determines the successive appearance and disappearance of coloured spots in the mantles of several of the cephalopods. Geographical distribution. Warm climates of the old world, South of Spain, Africa, East Indies, Isles of Sechelles, Bourbon, France, Moluccas, Madagascar (where it is said that there are seven of the species which belong to Africa). Fernando Po, and New South Wales. Species. The family consists but of one genus, Chama leo, but there are several species. We select Chamaleo vulgaris as an example. Localities, Africa and India. Egypt, Barbary and South of Spain, Cuvier. Central Africa, Col. Denham. India, Gen. Hardwicke. Tripoli, Mr. Ritchie. Egypt, Geoffroy. See General Hardwicke's and Mr. Gray's paper on the saurian reptiles of India in the Zoological Journal, vol. iii, p. 221, where it is observed that the teeth are rarely (as they are described to be by Cuvier) slightly three-lobed. When the animal is alive and in health, the angles of the occipital pyramid and the lines on the side of the face are completely obliterated. It is distinguished from a species from Central Africa, by the occipital keel extending to the centre of the eye, by the back of the head being only slightly lobed, and by the frontal scales being tubercular.' |