EXTRACTS FROM FOREIGN JOURNALS.

ZOOLOGY.

REMARKABLE INSTANCE OF INTELLIGENCE IN A DOG.-M. Alph. De Candolle has communicated the following observations on the instinct of animals :—Being last October in the neighbourhood of Aiguesmortes, I had occasion to observe a remarkable instance of intelligence in a Dog. The day was hot, and the season unfavourable, by reason of the trade winds so troublesome on the shores of the Mediterranean. After walking several hours in the desert which separates the town of Aiguesmortes from Camargne, we arrived at a plain where we found, in the midst of a whirlwind, some remains of a shipwreck. Out of three Dogs which had followed our guide, two only accompanied us to this spot. Their black hair attracted the rays of the sun, and the poor creatures, like ourselves, seemed to find the sand somewhat too warm to be pleasant. I sat down on a mat half buried in the sand. One of the Dogs quickly conceived the idea of establishing itself near me. It nestled close to a horizontal plank, by way of procuring a little shade, but finding this insufficient, it hollowed the sand until it came to the part moistened by the sea. It then stretched itself with delight in this fresh and shady bed. There, said I, is an undoubted instance of reason. Had it been instinct, every animal of the same species placed in similar circumstances, would have acted alike. But the other Dog, though of the same race and also weary, knew not what to do; it writhed on the hot sand. One of these Dogs evidently remembered that by hollowing the sand hillocks, a cool and moist part is arrived at, and it applied the reminiscence to this particular case. It may perhaps be said that the Dog which made no burrow, had never been on the plain, and had therefore had no opportunity of ascertaining the coolness of the sand underneath. But this is not probable, since both Dogs had been accustomed to the sea shore. This, again, is another difference between instinct and reason; instinct acts without previous experience. The Dog of Peccai, the less sagacious of the two, might perhaps one day have learnt to burrow to the cool part of the sand hills.-[From our own observations, we are convinced that M. De Candolle is right, and that many animals, as the Horse, Dog, &c., &c., possess reason-some individuals even in a considerable degree.-EDS.]

MONOGRAPH ON THE ARVICULES OF LIÈGE. The smaller quadrupeds are among the vertebrated animals which present considerable difficulties to the naturalist, in the discrimination of species. M. Sélys Longchamps has endeavoured to disembrangle the history of the Arvicules; he has found five species in Belgium, three of which were already known in France and Germany, and the other two are new. The number of Arvicules in central and western Europe amounts, then, to six. Here follows an enumeration of the five Belgian species :—Arvicola fulvus, Desm. Length of the body, 3 in. 21., of the tail, 111.; ears scarcely visible.-A. amphibius, Desm., (Mus amphibius, Linn.). Length of body, 6in. 31.; tail, 3in. 4l.—A. arvalis, D.S.L. (Mus

arvalis, Linn.). Length of body, 3in. 91. ; tail, lin. 11. ; ears of moderate size. A. subterraneus, D.S.L. Body, 2in. 91. ; tail, lin. 11. ; ears of moderate size, tail black above, whitish beneath; eyes very small.-A. rufescens, D.S.L. Body, 2in. 91. ; tail lin. 41.; ears rather large; tail black above, whitish below; eyes prominent. This monograph contains four plates, figuring four of the species of the natural size, and giving the heads of two.

A NEW INSTANCE OF A SHOWER OF TOADS.-M. Pontus, a Professor, at Cahors, has communicated to the Académie des Sciences of Paris, another instance confirming the truth of the showers of Toads which have already often occupied the attention of the Academy. "In the month of August, 1834," he writes, "I was in the diligence from Alby to Toulouse; the weather being fine and clear. About four o'clock in the afternoon, three leagues from Toulouse, a dense fog suddenly covered the horizon, and loud peals of thunder were heard. This mist burst upon the road, at about 120 yards (60 toises) from where we were. Two horsemen, returning to Toulouse, whither we were going, and who found themselves exposed to the storm, were obliged to put on their great coats; but what was their surprise and consternation when they were assailed by a shower of Toads. They quickened their pace, and eagerly pressed forward, as soon as they met the diligence, to relate what had happened. I still saw some small Toads upon their cloaks. When the diligence reached the spot where the fog had burst, we beheld the road, and the fields on both sides, covered with Toads, of which the smallest was at least an inch in length, and the largest about two inches, which led me to suppose they were one or two months old. There were three or four layers super-imposed one above the other. The feet of the horses and the carriage wheels crushed many thousands. On the road thus covered we travelled at least a quarter of an hour, at the usual pace.”—Bib. Univ. de Genève.

BOTANY.

NEW FOSSIL PLANTS FOUND IN NORTH AMERICA.-Dr. Harlan has published, at Philadelphia, a thick volume entitled Medical and Physical Researches, &c., 1835. This work contains various papers on Medicine, Zoology, &c. We extract the following notes on various species of fossil plants, recently found in the United States :-Pecopteris obsoleta. This species bears considerable resemblance to P. Cistii of Brongniart, but differs in having the veins of the segments of the leaves slightly, or not at all marked. It occurs in the sandstone of the bituminous strata of coal.

Pecopteris Milleri.-P. Pinnulis obliquis rectis linearibus elongatis vix distinctis nervulis simplicibus valde obliquis. Found in the same localities as the preceding, and resembles the P. Beaumontii, Brong.

Equisetum stellifolium.-E. caule erecto simplici lævi cylindrico, diam. 1-8 pollic. subæquali, ramulis 10-12 ad articulationes caulis verticillatis stelliformibus, articulis vix distinctis superne approximatis, vaginis indistinctis. Occurs in coalfields and bituminous earth in Pennsylvania.

Fucoides Alleghaniensis.—F. fronde compressá rugata apice recurvâ obtusá, ramis inæqualibus digitatis et fastigiatis enervibus nudatis. Found in the compact sandstone under the coal formations, on the mountains bordering the river Juniata, near Sesquehanna.

Fucoides Brongniartii.-F. fronde elongatâ subquadrangulari canaliculatá transverse rugosâ, ramulis inæqualibus sparsis remotis compressis rugatis recurvis nudis. Met with in the same localities as the foregoing species, in the western parts of the State of New York, and near the Welland canal in Canada. -Bibliothèque Universelle de Genève.

METHODS OF CONVERTING ANNUALS INTO VIVACIOUS AND LIGNEOUS PLANTS; by M. Pépin, principal of the Botanical School of the Paris Museum of Natural History.—Two methods are commonly employed for transforming annuals or biennials into vivacious or woody plants :-1st. By preventing the growth of the seeds; 2nd. By grafting an annual upon a vivacious species. Besides these two modes, M. Pépin mentions a third, of which he records but one example, but which deserves to be studied, as an entirely novel circumstance in Vegetable Physiology, namely, the grafting a vivacious plant upon an annual. Let us review the three methods. The first is that most frequently employed. Annuals and biennials only die from weakness induced by the formation and maturation of the seeds. They have aptly been compared to women who die in child-birth. When no seeds are formed, the flowers are double. Thus the double Nasturtium is vivacious, and is produced from slips. M.Pépin has kept plants upwards of twelve years. Chrysanthemum coronarium and Senecio elegans, become double by cultivation, are equally vivacious. The result is the same when the formation of single flowers is prevented or diminished. Corn lasts as long as the intemperatures, (intempéries) or the hand of man prevent it from forming its ears. The Reseda becomes ligneous when the lower stalks, and all the flowers developed during the first year, are removed. Hibiscus vesicarius and trionum, Anthemis triloba, Ageratum cæruleum, Cassinia spectabilis, Enathera biennis, grandiflora, salicifolia, many Malva and Sida-all ornamental annuals become vivacious and more or less ligneous when prevented from flowering at their usual time, or by removing the upper and lower branches. The plants must be housed in winter, as they are natives of a warmer climate than our own. The plan of grafting annuals upon ligneous species is intended to increase the quantity of the sap, in order that they may not be exhausted by the formation of the seeds. Pépin has grafted Ipomea purpurea on Convolvulus paHe made use of the Red Potato, and grafted on one of its branches at the height of a foot. Since the time of the operation (1831), the Purple Bindweed (Liseron pourpre) has put forth several branches, which produced annually abundance of flowers. Kept in a pot, it has almost become woody, and is put every winter into a warm greenhouse. The herbaceous graft, now so successfully employed, furnishes also some remarkable examples. Many annual Solanacea will live a considerable time when grafted on ligneous species of the same genus, or even upon the stems of Potatos, provided they are kept in a warm place in winter. The various annual Tobacco plants may be grafted on the Nicotiana glauca, that beautiful woody species which grows to a greater height than a man. All grafts answer well-whatever be the cause-in a slip or crown, and can live there a considerable time. It is necessary to suppress the first flowers which appear, and to pull off the ends of the branches developed by the graft, in order to give it vigour and to increase the number of ramifications. If the plants grafted are unable to bear the cold, they should be put into the greenhouse. The neighbouring genera, Petunia, Nierembergia, &c., grafted on Nicotiana glauca, or on Taba

tatas.

cum, become equally vivacious and woody. Dianthus caryophyllus and lignosus, are very suitable for receiving the graft of annuals or biennials, as D. sinensis, barbatus, moschatus, so common in gardens. The grafted plants should be taken into the house in winter. The Potato, a vivacious plant, has been grafted upon the Purple Bindweed, and has caused the latter to be so far vivacious as to live three years! Its stem has become thicker than a goose-quill. "It was expected by this means," says M. Pépin, "to hasten the flowering of the Potato, which to this day is scarce of flowers; but if experience has not realized this hope, the result is not the less interesting." May we not conclude, from this observation, that the species grafted not having exhausted the subject by the flowering, this has become vivacious, as if it had been prevented from flowering without being grafted? This method, which at first sight appears singular, is, notwithstanding, probably a confirmation of the principle that it is the formation of seeds that kills annuals.-ALPHONSE DE CANDOLLE, in the Bib. Univers. de Genève, No. 12.

GEOLOGY.

ON THE BASILOSAURUS; A NEW GENUS OF SAURIAN FOSSIL, DISCOVERED IN AMERICA. The discovery of this species is due to Judge Bree, of Arkansas, who found, in 1834, the first vertebra on the fenny margin of the river Washita. Towards the close of the same year, other vertebræ, fragments of the lower jaw, &c., were discovered at Alabama, thirty miles from Chairbome. Several immense vertebræ, teeth, ribs, parts of the shoulder, humerus, tibia, &c., have been obtained; and in May, 1835, another skeleton, promising a rich collection of fossil remains, was found. Near it was a vertebra of the tail of the Mosaurus, or Crocodile of Maëstricht. All these bones, though differing in their proportions and size, belong to the same species; the structure of the lower jaw, which is hollow, indicates that it is an extinct genus of the Saurian class. The comparatively small size of the bones of the extremities, seems to prove that the tail was the principal organ of motion; the anterior members ought to have been fins. The row of vertebræ, extending to more than 100 feet in one specimen, and estimated at upwards of 150 feet in that of Arkansas, proves this enormous animal to have attained or even exceeded these dimensions; and it well deserves the name it has received-Basilosaurus, or King of the Saurians.

MINERALOGY.

THE PROBABLE ORIGIN OF THE DIAMOND.-Naturalists have proposed hypotheses as to the origin of the diamond which ascribe it to a vegetable, and not a mineral, formation. Jameson attributes it to the vegetable secretion of some patriarchal or antediluvian Baobad or Banyan tree of the world before the flood. Brewster considers the stratum in which it is found as neither the production of water or fire, and the diamond itself, like amber, from its combustibility and its powerful reflective properties, as a consolidation of vegetable matter, which has gradually acquired crystallization. Jameson's view is supported by many remarkable analogies of the formation of silex in various Indian plants, as the formation of lime is known to take place in others. The genus Chara is especially rich in the latter as well as the ex

traordinary group of corallines, which have hence frequently been considered as animals. The formation of silex occurs pre-eminently in Indian grasses, bamboos, and even trees. Dr. Moore observed that within the Circars, as far as Nagpore, consequently within the district watered by the Kistna and Godavery, a species of Jungle grass, with which Dr. Roxburgh was unacquainted, grows in immense quantities upon the mountain heights, in the knots of which a secretion of perfect silex takes place. The Calamus rotang, Equisetum hiemale, and certain species of bamboo, also produce these secretions of silex, which are better known by the name of Tabaschir, or vegetable opal. The bamboo in which this Tabaschir is secreted, Langford Kennedy observed in great quantities in the wilds of the mountain around Ramguhr, thirty geographical miles to the west of Calcutta, consequently in the vicinity of the sources of the rivers Brahmani and Mahanadi, along which it may also be distributed. This species of Bambas is called at Ramguhr Kutbinbanse-that is, prickly wild bamboo-and the siliceous secretion Banselochum. It is not every plant which produces this secretion; those who seek it shake the stems, and detect it by its rattling within those plants which exceed in their stem two inches and a half in diameter. In the eastern islands it is found in much larger stems, but it is then of a dirty yellow colour. There are two different kinds; the one nearly white, but opaque, and the other resembling opal, but without any polish. The physicians of the Hindoos use it as a medicine, and it costs from eight to ten shillings the pound. Dr. Turnbull Christie observes that this Tabaschir is not found in all parts of India, nor in all the species of the same genus of bamboo, nor even in all the bamboos of the same locality. The secretion of this silex, therefore, may be referred to certain local and individual vegetable peculiarities which stand in a yet unknown connexion with its range of occurrence, like that of the diamond. As long as the bamboo is green the Tabaschir is moist and transparent, analogous to chalcedony in basalt, which becomes opaque by exposure to the air before it can be removed from the fissure. The Tabaschir possesses a similar property to Chalcedony, for by chemical analysis it produces silex. The bamboos are not the only plants which produce silex. The iron-wood, Calumidiri, and others which have been brought from the forests of Ava, are so filled with condensed carbon that they acquire almost the hardness of diamonds, and rather resemble petrifactions than succulent vegetables. It therefore becomes probable that many of the so called petrified species of wood have killed themselves by a superabundant secretion of the siliceous matter; whence we may comprehend their wide dispersion in both the deserts of Africa and Asia. Similar concretions of silex have frequently been found in abundance in the hard teak wood, the analysis of which, according to Wollaston, gave silex which appeared to come most closely to the diamond carbon, and seemed to support Jameson's interesting hypothesis of the possibility of a vegetable origin of this jewel, but which, indeed, still requires many experiments and observations to confirm.-Ritter Erdkunde, vi., 365.

MISCELLANEOUS.

VAN MANDER AT FLORENCE. Two thirds of the fifteenth century-at which period commenced in Belgium the revival of painting by the invention