AND OF THE PHYSICAL SCIENCES. 



135 



and contractile stalk ; with numerous ciliated and jointed tentaculary bodies attached 

 to the respiratory organs ; the shell compressed, of five unequal contiguous valves, 

 the lower lateral valves larger. Several species are kno^n, of which the most com- 

 mon is that here figured. 



I 



Anatifa lavis^ the Smooth Bernacle ShoU. — In this species the shell is comprossec\ 

 and comparativfly smooth, the striae on its surface not being prominent as in another 

 species, named on that account A. striata. This shell is composed of five pieces, two 

 lateral, and one dorsal; the lower lateral pieces much larger tlian the upper, and the 

 dorsal very narrow and keeled. The pieces are connected by membrane, unless in 

 fi-ont towards the top, where the tentacula project. The body of the animal is of an 

 ublong compressed form, curved and envelojied in a soft skin or mantle. Appended 

 to the branchije or respiratory organs arc ten pairs of long, slender, tapering, curved, 

 and ciliated tentacula, five pairs on each side. At their base are two shorter pairs, 

 and several small flattened and curved organs, equally ciliated, but connected with the 

 mouth. The shell is about an inch and a quarter in length, and is supported upon 

 a peduncle varying in length from a few inches to a foot or even two feet, and in 

 iliameter from a quarter of an inch to half an inch. This peduncle is of a reddish 

 colour, and has an external, transversely corrugated, elastic, cuticular envelope, whieh 

 at its base is attached to a piece of wood, floating or fixed in the sea, and at its upper 

 part to the shell. Internally it consists of a cylinder of longitudinal, whitish, muscular 

 fibres, separated by a large quantity of aqueous fluid, and at the base adhering to the 

 cuticle, which covers the wood, while at the top of the peduncle they are continuous 

 with the body of the animal. The contraction of these muscular fibres of course 

 shortens the peduncle, and throws its envelope into strong transverse wrinkles. These 

 animals adhere often in great numbers to timber of any kind floating in the ocean, to 

 logs, portions of wrecks, casks, and the bottoms of vnssels, and are frequently thrown 

 ashore on the western coast of Britain. Gulls of difi'erent species, but particularly the 

 Great Black-backed and Herring Gulls, sometimes eat the animal as well as its 

 fleshy peduncle. A foolish notion was once generally entertained respecting this ani- 

 mal, and is still prevalent among uneducated persons, namely, that the Bernacle or 

 Brent Goose, Anser Bernicla and A. Brtnta^ originate from it. Thf ciliated tenta- 

 culary organs, which have some slight resemblance to feathers, were the cause of tb's 

 misconception, having been taken for the sprouting quills of the young bird. 



BOTANY. 



Victoria Regia. — On lhe22d January was read to the Royal Geographical Society 

 of Lundon, a note upon this plant by Professor Lindley. " I have great satisfaction in 

 stating to the Society, that some specimens of the flowers of this extraordinary 

 plant, which have lately been received from JI. Schomburgh, completely confirm the 

 statement of that traveller in all essential particulars, and at the same time establish 

 the new genus Victoria upon the most complete evidence. The most startling cir- 

 cumstance named by I\I, Schomburgh was, that the flowers measured fifteen inches 

 in diameter ; one of the specimens now received measures fourteen inches in diame- 

 ter, although its petals have rotted off" in consequence of the bad manner in which 

 they have been prepared. With respect to the genus, it has been already mentioned 

 in the Journal of the Geographical Society, at my nquest, that although Victoria is 

 possibly the same as the Euryale amazonia of Pieppigj yet it is, in my opinion, quite 



distinct from the latter genus. I am not aware that any one in this country, of any 

 botanical reputation, has calhd this opinion in question ; and therefore it may appear 

 unnecessary to notice it further. But Professor Paeppig is so good a naturalist, that 

 it is due to him to state upon what grounds I consider him to be wrong in the genus 

 to which he referred the plant. Euryale is an East Indian water plant, with very 

 large floating leaves, sometimes as much as four feet in diameter, light purple under- 

 neath, and there reticulated with numerous very large prominent veins. It is, however, 

 covered with sharp prickles on the under side of the leaves, the leaf-stalks, flower- 

 stalks, and calyx. In these particulars it agrees with Victoria, but in little else. 

 Victoria has the inner petals rigid, and curved inwards over the stamina, into which 

 they gradually pass ; in Euryale there is no transition of this kind. In Victoria there 

 is a double row of horn-like sterile stamens, curving over the stigmas, and adhering 

 firmly to their back ; Euryale has no such structure. In Victoria there are thirty- 

 six large, uniform, compressed fleshy stigmas ; in lieu of this very singular character, 

 Euryale has only the margin of a cup, with six, seven> or eight curvatures. Victoria 

 has twenty-six cells to the ovary ; Euryale only from six to eight. And, finally, to say 

 nothing of minor distinctions, the ripe fruit of Victoria lies at the bottom of a regularly 

 truncated cup, which stands high above the water, while the flower of Euryale sinks 

 into the water after flowering, and the fruit, when ripe, is invested with the decayed 

 remains of the calyx and corolla. These facts will, 1 think, confirm my original 

 statement, that, notwithstanding the prickles of the leaves and stalks, the gt-nus Vic- 

 toria is more closely allied to Nympheea than to Euryale, and will, 1 hope, set at rest 

 all future ingenious speculations upon the first of these genera being untenable." 



G E O L O GY. 



Remarks on the Erratic Blocks of the Juha, by M. Agassiz. — Having 

 spent several months in the neighbourhood of the Alps, for the purpose of studying 

 the glaciers, and of examining the observations of JIM. Venetz and Charpentier on 

 the great moraines found at a distance from existing glaciers, he was not less struck 

 by the polished appearance presented by the rocks on which they had moved. The 

 flanks of the valley of the Rhone are entirely polished, even to the borders of the 

 Lake of Geneva, more than a day's journey from the glaciers, wherever the rock has 

 been hard enough to withstand the action of the weather. On seeing this phenome- 

 non, evidently produced by the glaciers, which, when they retired, left on their edges 

 the concentric masses of rolled blocks named morurnts^ he remembered that the 

 northern slope of Jura, which faces the Alps, presents similar polished surfaces, term- 

 ed lavts, and on his return to ^'eufchatel, he hastened to examine them more atten- 

 tively. He found that they have no connection with the stratification of the rocks, or 

 with the direction of the chain of mountains, and that they extend along the wliole 

 surface, following its undulations, and presenting an uninterrupted smooth surface 

 wherever the rock has been recently exposed. The furrows which often traverse 

 these surfaces never occur in the direction of the slope of the mountain, but are ob- 

 lique, so that they could not have been caused by currents of water; and the minute 

 markings on the surface are generally parallel to these furrows. It appeared evident 

 that this polishing had been produced by ice; it was found to occupy an extent of 

 more than twenty leagues to the oast and west of Neufchatel, although no one had 

 liken notice of it. As the erratic blocks of the Jura are found resting on these po- 

 l:shed surfaces, the question naturally occurs, whether, as M. Charpentier once sup- 

 posed, the glaciers had extended to the Jura, pushing before them blocks of Alpine 

 rocks, and polishing tlie surface on which they moved. Such an idea is confuted by 

 the fact that the erratic blocks of the Jura are angular, while those of the moraines 

 are always rounded, as are also those of existing glaciers. If, therefore, the erratic 

 blocks in question had been pushed by glaciers to so great a distance, they ought to 

 be much mure rounded than those of the moraines, which ought also to have been the 

 case had they been transported by currents of water. Had the latter been the agent, 

 it is impossible to account for the lakes between the Alps and Jura not having been 

 filled up, especially as it can be demonstrated that they existed previously to the 

 blocks. Nor can the phenomena be accounted for by the supposition of the angular 

 blocks having been transported on floats of ice moved by currents of water : for the 

 erratic blocks of Jura do not rest immediately on the polished surfaces, but on a bed 

 of rolled pebbles several feet in thickness, the larger at the surface, and the smaller, 

 often as fine as sand, at the bottom. Now, had the transportation been effected by 

 currents, the reverse would have been tha case. The existence of fine sand on the 

 surface of the polished rocks, also proves that no powerful cause has acted on the sur- 

 face of Jura, since the period at which these Alpine rocks were transporteil ; and the 

 fine lines on the polished surfaces are no doubt due to this sand, which, however, 

 could not have been moved by a current of water, for neither torrents nor lakes, when 

 charged with sand, produce any thing analogous on the same rocks. I\I. Agassiz is of 

 opinion that most of the phenomena attributed to great diluvial currents, and especi- 

 allv those recently described by M. Selfstroem, have been produced by ice. 



MISCELLANEOUS. 



Peakl-Fishing in Arabia. — The Pearl-bank extends from feharja to Biddulph's 

 Group. The bottom is of shelly sand and broken coral, and the depths vary from five 

 to fifteen fathoms. The right of fishing on the bank is common, but altercations between 

 rival tribes are not unfrequent. Should the presence of a vessel of war prevent them 

 from settling these disputes on the spot, they are generally decided upon the island 

 where they land to open their oysters. In order to check such quarrels, which, if 

 permitted, would lead to general contusion, two government vessels are usually cruising 

 on the bank. The boats are of various sizes, and of various construction, averaging 

 from ten to fifty tons. During tme season it is computed that the island of Bahrein 

 furnishes, of all sizes, three thousand five hundred ; the Persian coast, one hundred ; 

 and the space between Bahrein and the entrance of the Gulf, including the Pirate 

 Coast seven hundred. The value of the pearls obtained at these several ports is es- 

 timated at forty lies of dollars, or four hundred thousand pounds. Their boats carry 

 a crew varying from eight to forty men, and the number of mariners thus employed 



