animals, which is in fact corrected in the latter part of the volume. In referring to Prof. Tuckerman, we hope it may be long before he must be designated as "the late distinguished American lichenologist." The "conjecture" which "may be hazarded" that the Red Sea "acquired its denomination from the prevalence of this red alga [Trichodesmium erythraum] in its waters," was hazarded by Ehrenberg, if we mistake not, at the time of its discovery. The late Dr. M. A. Curtis, our American mycologist, informed Mr. Berkeley, as we remember, that he and his neighbors whom he instructed, procured no small supply of excellent food from the edible Fungi, which grew around his home, in the center of North Carolina, so abundantly that he opined he might have supported a regiment on them. This, we suppose, is the whole foundation for the extraordinary statement that, "During the latter part of the American war, when meat was scarce and dear, fungi, which grow in immense profusion and variety in America, formed the principal food of the Southern army."

A. G.

3. Seeds that float in water have a certain interest in connec tion with questions about dissemination. Many ranked as such are fruits, botanically speaking, with spongy or cellular pericarp, or with some air-space between the pericarp and the seed itself. But there are a considerable number of true seeds with specific gravity less than that of water, some as low as 0.75. Van Tieghem (Ann. Sci. Nat., ser. 6, i, 383) finds that this is due to different causes. More commonly the seed owes its lightness to its coats, either by a separation in drying between the two, or between the inner and the kernel, leaving an air-space, or by a loose cellular structure of the coat. Sometimes, as in castor-oil seeds, the integument is heavier than water, but the kernel is so much lighter as to float the seed. This comes from a separation of the two cotyledons during the natural desiccation, leaving a considerable cavity filled with air. This is strikingly the case in the large, flat, and very dense-coated seeds of Entada scandens, which are well known to have been wafted across the Atlantic from the West Indies to Northern Europe and left in a condition fit for germination; while in those of Guilandina Bondue, which have been known to accompany the former, the air is interposed between the embryo and the bony coat. The embryo itself, in all such cases, is heavier than water. But to this rule Van Tieghem now brings to light a few exceptions, and these in leguminous seeds. In those of Erythrina crista-galli, the specific gravity of the whole seed is 0.91, that of the embryo itself 0-87. Those of our Apios tuberosa are a little lighter, of our Wistaria frutescens a little heavier than this, but still lighter than water; and various common leguminous seeds, although heavier than water, are much lighter than would be supposed. This proves to be owing to a very loose and open structure of the parenchyma of the inner or upper side of the cotyledons (that which answers to the upper face of the leaf), leaving abundant intercellular spaces and passages, filled with air, which renders this spongy stratum light enough in certain cases to float the otherwise heavy seeds.

A. G.

4. Use of the hygrometic twisting of the tail to the carpels of Erodium.-We have no indigenous or common Erodium this side of Texas; but there and in California one or two species are common. The narrow carpel is pointed at base; the long awn or style in drying bends at right angles with the carpel, and twists in many turns, depending on the amount of dryness, and untwists in a moister air or when wet. We had wondered that no one seemed to have given an account of the way in which this mechanism acts so as to bury the seed in the ground. Dispersed by the wind over the loose or sandy soil which these species prefer, the seed-bearing end being the heavier lies next to the ground, and is the comparatively fixed point, around which the long awn makes circular sweeps, whether in twisting or untwisting. This gives a rotary movement to the carpel, fixes the sharp end in the soil, and, whether twisting or untwisting, causes it to bore into and bury itself in the ground. It is the same with the grain and awn of Stipa. As to Erodium, we have just found that this is described by G. Roux, in the Annals of the Botanical Society of Lyons, France. He adds that, when in this way thus interred, the moisture of the soil soon destroys the epidermis and this allows the long beak to detach itself at its articulation with the style, leaving it planted in good condition quietly to germinate. M. Roux enters into details about the effect of light, heat, chloroform, etc., upon this movement, which seem to us superfluous and wide of the mark.

A. G.

5. The Lemurs not related to the Monkeys.-In the genealogical tables of Hæckel, the Lemurs are made the point of divergence of lines leading to the Insectivores and Carnivores on one side and to the Rodents and the Monkeys on the other. MM. Grandidier and Alph. Milne Edwards, in their recent work on the Mammals of Madagascar, show that the Lemurs have striking peculiarities in the conformation of the allantois and placenta, and not the close relation to the monkeys generally supposed. By injecting the capillary vessels of the placenta and uterus they have studied the vascular relations of the fetus with the mother, and established thus profound differences between the two types, which begin even in their intro-uterine life.-L'Institut, Dec. 29.

6. Fauna of the Greenland Seas.-The Fauna of the Greenland Seas, according to results obtained by the "Valorous" (on its return from Disco), agrees with its land flora in being mainly Norwegian, there being (with the exception of the Echinoderms) an absence of many North American forms, which, as it appears, have not been found east of the meridian of Cape Chidley in Labrador. A Campanularia was obtained identical with one found by Mr. Eaton, of the British Transit-of-Venus Expedition, at Kerguelen's Island; also, in the towing-ne, a sponge-like diatom, Synedra Jeffreysi Dickie, with living Globigerinæ entangled in the connecting protoplasmic matter of its frustules. The deep waters of Davis Straits afforded a mollusk which was long since found fossil in the newer Tertiary of Sicily, and was supposed to be extinct.-Proc. Roy. Soc., No. 164, p. 78.

IV. ASTRONOMY.

1. New Planet.-The discovery of another planet by Herr Knorre was announced by telegram to Prof. Henry, Jan. 11th.

2. Harvard Observatory Engravings.-The last instalments of the engravings from Harvard College Observatory have been distributed to the subscribers. Instead of 30 plates as promised, 35 have been issued. These later plates represent two star clusters, six views of nebulæ, four views of Donati's comet, and three of Coggia's comet. A letter press description of the engravings is, we understand, to be soon issued.

3. The Uranian and Neptunian Systems investigated with the 26-inch Equatorial of the U. S. N. Observatory; by Professor NEWCOMB. Appendix I of the Wash. Obs. for 1873, p. 74.This paper is the first extended contribution of results obtained by the large Washington telescope. It is a discussion of the observations made between November, 1873, and May, 1875, upon the four satellites of Uranus, and the satellite of Neptune. It closes with tables of the motions of the satellites, for a portion of which credit is given to Prof. Holden.

Prof. Newcomb obtains as the most probable value of the mass of Uranus, with an estimated probable error of the denominator of 100. He finds no evidence of any mutual inclination of the orbits of the four satellites and but slight evidence of any real eccentricity. The following are the mean distances from Uranus at the mean distance of Uranus from the sun: Ariel, 1378; Umbriel, 19"-20; Titania, 31" 48; and Oberon, 42" 10. The periods of revolution are 24-520378; 4-144537; 84-705897, and 134-463269. The former two are not changed from the determinations of Lassell and Marth. The inclination of the plane to the ecliptic is 97°-85-0.013T, counting from the epoch 1850.

The only means of estimating the masses of the satellites is a comparison of their light with that of the planet. From this Prof. Newcomb infers that they probably do not exceed 18 of the planet. If so their mutual action, and the sun's action on them, are of no importance. Prof. Newcomb adds: "I think I may say, with considerable certainty, that there is no satellite within 2' of the planet, and outside of Oberon, having one-third the brilliancy of the latter, and therefore that none of Sir William Herschel's supposed outer satellites can have any real existence. The distances of the four known satellites increase in so regular a way that it can hardly be supposed that any others exist between them. Of what may be inside of Ariel, it is impossible to speak with certainty, since, in the state of atmosphere which prevails during our winter, all the satellites would disappear at 10" distance from the planet. The planet always presented itself of a sea-green color. No variations of tint were ever seen. Markings on the planet were not especially looked for, but had any been visible they could hardly have escaped notice."

For the mass of Neptune the value τ is obtained. In the

perturbations of Uranus, Prof. Newcomb used too. The distance of the satellite from Neptune is 16 275, its daily motion 61°25679, its inclination to the ecliptic 145°12; and the orbit so far as observations show is circular.

No trace of a second satellite of Neptune has ever been seen, though it was several times carefully looked for under the finest atmospheric conditions.

V. MISCELLANEOUS SCIENTIFIC INTELLIGENCE.

1. Report on the Compressive Strength, Specific Gravity, and Ratio of Absorption of Building Stones in the United States; by Q. A. GILLMORE. 38 pp. 8vo, with two plates. 1876. Official Report to the Chief of Engineers, U. S. Army. (D. Van Nostrand.)— This report contains the results of a very careful series of experiments on various building stones of the country. The method of experimenting in the crushing is particularly described, and the results as to crushing-strength with the cubes of stone in different positions, and between wood, lead and leather cushions, etc., are given in detail. The tables contain entries of 99 experiments on granites, 43 on limestones, 12 on marbles, and 62 on sandstones.

2. Science and Art Department of the Committee of Council on Education, South Kensington.-The Loan Exhibition of Scientific Apparatus will open on the 1st of April, 1876, and remain open until the end of September. It will consist of instruments and apparatus employed for research and other scientific purposes for teaching, and for illustration of the progress of science and its applications to the arts. Models, drawings, and photographs will be admissible where originals cannot be sent. Forms on which to enter descriptions of objects offered for exhibition may be obtained on application to the Director of the South Kensington Museum, London, S. W., and these forms should be filled up and returned as soon as possible, so that exhibitors may receive early intimation as to the admissibility of the objects they propose to send. The Science and Art Department defrays the cost of carriage, but, while using all possible care, is not responsible for loss or damage. The circular issued expresses the hope that institutions or individuals having instruments of historic interest will be good enough to lend them. The instruments and apparatus desired are of all important kinds connected with the subjects of arithmetic, geometry, measurement, kinematics, statics, dynamics, molecular physics, sound, light, heat, magnetism, electricity, astronomy, applied mechanics, chemistry, meteorology, geography, geology and mining, mineralogy, crystallography, biology, (microscopes, &c.)

3. Works on the Paleontology of the Rocky Mountain Surveys in progress.-The first four months of this year will witness the publication of an unusually large number of works on the invertebrate paleontology of the great Rocky Mountain and adjacent regions, some of which have been delayed several years. The following are either partly or wholly in type and will soon be published.

(1.) Paleontology of the Upper Missouri, by F. B. Meek; a quarto volume of between 500 and 600 pages of text and 45 lithographic plates of illustrations. It is confined to fossils of the Cretaceous and Tertiary periods, and is a very exhaustive treatise.

(2.) Paleontology of Clarence King's Geological survey of the 40th parallel, quarto, by F. B. Meek. This Report comprises about 150 pages of text and 17 lithographic plates. It embraces fossils of Lower Silurian, Devonian and Carboniferous ages and of the Triassic, Jurassic, Cretaceous and Tertiary periods.

(3.) Paleontology of the Report of Capt. Simpson's expedition; quarto, by F. B. Meek. Comprises about 100 pages of text and 5 lithograph plates. Cretaceous and Tertiary periods.

(4.) Paleontology of the Report of Capt. McComb's expedition; quarto. Cretaceous fossils, by F. B. Meek and Carboniferous fossils by J. S. Newberry.

(5.) Paleontology of parts of Vancouver's Island and Washington Territory, by F. B. Meek. About 100 pages octavo, and 6 plates. (6.) Invertebrate Paleontology of Lieut. Wheeler's Explorations and Surveys west of the 100th meridian; quarto, by C. A. White. About 220 pages of text and 21 lithographic plates. This report embraces fossils of the Primordial, Canadian, Trenton, Subcarboniferous, Carboniferous, Jurassic, Cretaceous and Tertiary periods.

(7.) Preliminary Report on the Invertebrate Paleontology of the Plateau Province, by C. A. White, quarto; about 50 pages. It will embrace fossils of the Carboniferous, Jurassic, Cretaceous and Tertiary periods. Among other important facts it will contain an announcement of the existence of open-sea marine deposits at Bijou Basin, forty miles east of Denver, Colorado; the fossils of the deposit belonging to the genera Venus, Mesodesma, Dentalium, Phorus and an Oculina undistinguishable from the species common in the Vicksburg Tertiary beds. This is to form a part of a report nearly ready for publication by Professor J. W. Powell, Chief of the Second Division of the Geological Surveys of the Interior Department.

C. A. W.

4. Geological Map of the 40th Parallel Survey.-Map number II, by CLARENCE KING, Geologist in Charge, and S. F. EMMONS, Assistant Geologist, has been issued as authors proofs, dated Nov. 15th, 1875.—This map, which covers the Green River Basin and most of the Uinta Mountains, a region of great geological interest, will be regarded as a model, as it has not been surpassed in accuracy and artistic execution by any similar work in this country. It is in two sheets, each 24 by 33 inches, and is on a scale of four miles to the square inch. It is the first of the series issued, and will be noticed more fully when the other parts are published.

5. Depth of the North Pacific.-The soundings by the "Challenger" in the North Pacific as given in the Proceedings of the Royal Society, No. 164, afford the following results:

Ålong a line from California to the Sandwich Islands the mean depth is 15,180 feet; and the least depth, about half way, near 13,000 feet.

AM. JOUR. SCI., THIRD SERIES-VOL. XI, No. 62.-FEB,, 1876.