clude that a molecular re-arrangement (umlagerung) takes place below 70°. Different volumes of the salt Mg. SO, 6 H2O at 93° and 50° point to a new modification at 93° since Marignac determined its composition at 50°. The salt Zr SO4.6 H2O also shows a difference in volume at 40° and 69°.-(Ann. phys. chem., n.f., xvii., 561.) C. F. M. [108 R. H. R. METALLURGY. R. H. R. A great feat in metal-working. Messrs. Kloman rolled a steel strip 6 in. wide, in. thick, and 310 ft. long, at their mill at Allegheny. They have contracted with the U. S. spring car motor construction company for an unlimited number of these steel springs. This company had previously applied to all the large English and continental works, and to other American works, without finding any one ready to undertake the work. — (Iron, Nov. 17, 1882.) [109 Molecular condition of metals. - Kalisher has found that sheets of most metals may be rendered crystalline by heat. A zinc sheet will become crystalline at 307° F. tin and cadmium at 392° to 5360°. Most metals obtained by electro-metallurgy give the same result. - (Iron, Dec. 8, 1882.) [110 Steel-iron, M. Keil has succeeded in producing a welded metal which is stated to possess the characters of both iron and steel. It is prepared by pouring the fluid steel on one side of a partition in a mould, and fluid wrought iron on the other: the partition is made of such thickness that it will weld by the heat of the added fluids. This so-called steeliron is said to have been prepared in five ways: 1°, steel by the side of iron; 2°, steel between two layers of iron; 3°, iron between two layers of steel; 4°, a core of steel surrounded by iron; 5°, a core of iron surrounded by steel. (Iron, Dec. 15, 1882.) [111 Compression of metals. An improved method of treating all kinds of metals and alloys has been patented by Mr. Louis Clemandot of Paris; it consists in subjecting them, when raised to a temperature sufficiently high to insure the necessary ductility, to powerful compression, and then allowing them to become completely cool while still under pressure. An increased density and hardness is claimed for metals thus treated. — (Min. and sc. press, Nov. 18, 1882.) [112 R. H. R. R. H. R. and calamine, - -the latter having the axial relation, a b c 1: 1.5564: 0.47657,-and their similarity in composition, datolite being H B Ca Si O,, calamine H2 Zn2 Si Og. He can, however, show no relation between their composition and that of axinite.(Amer. journ. sc., Dec., 1882.) S. L. P. [113 Saussurit. By means of microscopical investigation, A. Cathrein has shown that this mineral is composed of numerous microlites of zoisite in a ground mass of feldspar. He also shows, by calculation from various analyses and optical examination, that the mineral has been derived from plagioclase, more seldom orthoclase, by a loss of silica and alkalies, and taking-up of lime, iron, and water; and that thereby the minerals zoisite and epidote have been formed, giving rise to the microlites, which with the remnant of feldspar make up the mass. (Zeitschr. kryst., vii. 243.) S. L. P. [114 Danburite. This interesting mineral, of which such beautiful examples have been described by Professors Brush and Dana from St. Lawrence County, N.Y., has been lately discovered at Scopi, in Canton Graubünden, Switzerland, and fully identified and described by C. Hintze. The crystals occur in prisms 2-15 mm. long, 4-3 mm. broad; are colorless to wineyellow, and brilliant. The author gives the results of crystallographic measurements, which agree very closely with those obtained from the American crystals with some additional new planes. In habit the crystals vary much from the American. As terminal planes, the pyramid (142), often occurring alone, and macrodome (101) are most frequent. The base, which never fails on the American crystals, was but once observed, and then as a doubtful crystal plane. The prismatic zone appears very much striped. On account of the abnormal size of one of the dome-planes or two adjacent pyramidal planes, the crystals often have a decided monoclinic appearance. The optical properties coincide with those of the American variety. (Zeitschr. kryst., vii. 296.) The above mineral has been analyzed independently by C. Bodewig and A. Schrauf, giving results which are wholly in accordance with the analyses of the American mineral. C. Bodewig's analysis gave SiO2 48.66, Ca O 22.90, B2 O, 28.09, Fe2 03 0.23, Al2 03 0.0899.96.(Zeitschr. kryst., vii. 391.) GEOLOGY. Lithology. S. L. P. [115 The trachytic rocks of Tokay, Hungary. — Professor Szabó gives in this paper the outlines of his new classification of trachytic rocks, the term trachyte covering for him about as extended a range as the term 'greenstone' used to do. His divisions are as follows: A. TRACHYTE WITHOUT BIOTITE. I. Augite-trachyte; with anorthite-bytownite, without biotite or quartz. Olivine very rarely found. II. Amphibole-trachyte; with labradorite-bytownite, augite rarely entirely absent. Quartz wanting. B. TRACHYTE WITH BIOTITE. III. Micaceous-amphibole-trachyte; with audesite-labradorite; with or without quartz, augite, and garnet. IV. Micaceous-amphibole-trachyte; with oligoclase-andesite, with or without quartz and augite. V. Micaceous trachyte; with orthoclase-oligoclase, with or without quartz and amphibole. Augite rarely absent. The micaceous trachytes are regarded as older than the others. The paper contains a discussion of the geological relations of the trachytes in general. The Tokay rocks are the following: 1. Augitetrachyte. 2. Amphibole-trachyte. 3. Micaceousquartz-trachyte. 4. Conglomerates and trachytic tufas. 5. Red plastic clay. 6. Prehistoric and recent alluvium. The microscopic, chemical, and geological characters of the rocks are given, with a discussion of their former nomenclature. ·(Assoc. franç. avanc. x. 532.) SC., In this connection attention may be drawn to two other papers by the same author, relating to the classification of the trachytes: Classification macrographique des trachytes (Bull. soc. géol. France, Dec. 7, 1881); and Die makrographische eintheilung der trachyte. - (Verhandl. k.-k. geol. reichsanst., 1882, 166.) M. E. W. [116 A new basaltic rock. - The name pyroxenite is given by Dr. C. Dölter to a rock from the Cape Verde Islands, composed of augite, magnetite, and a glassy base.(Verhandl. k.-k. geol. reichsanst., 1882, 140.) [117 M. E. W. METEOROLOGY. Ohio state weather service. This service, recently organized, has begun the publication of monthly reports. The November issue contains returns from nineteen stations, including five maintained by the U. S. Signal Service, accompanied by a wellarranged monthly summary. — W. U. [118 Observations at high stations. -The Austrian meteorological service established in 1880 self-recording instruments at Klagenfurt and Obirgipfel, stations situated near each other geographically, but having altitudes of 438 and 2,044 met. respectively. Hourly observations to the end of the year 1881 have been recently published, embracing those of pressure at both stations and of temperature at Klagenfurt only. (Jahrb. k.-k. centr. anst. meteor., 1882.) [119 W. U. Rainfall statistics. Systematic observations of rainfall throughout France are made by the Bureau central meteorologique. The results for 1880, deduced from 1,291 stations, have been collected and studied by M. Th. Moureaux, who publishes twentyfive charts in illustration: eight of these are designed to exhibit the connection between rainfall and barometric depressions, and confirm the opinion advanced by Prof. Loomis from his studies of the U. S. weather-maps, that rain is most abundant in advance of a depression, and that therefore the direction in which a storm will move can be foretold by the distribution of the rain areas. (Sur le régime des pluies en France pendant l'année 1880.) Mr. Symons, through whose efforts more than 2,000 stations in Great Britain have been established, has published valuable suggestions for securing uniformity of practice among rainfall observers. (Symons' meteor. mag., Dec., 1882.) W. U. - [120 Floods in France. Camille Flammarion describes the year ending with November, 1882, as one of very numerous rainy days, although of normal rainfall, in France. In Paris the rainfall at the Montsouris observatory was 543 mm., closely agreeing with the average of other years: but the number of rainy days was 208, and besides these, 100 more were cloudy. As a result, summer evaporation, which ordinarily disposes of much of the rainfall, was this year very ineffective; the ground became saturated, and when the November rains (113 mm.) came, the rivers rose rapidly throughout the country. -(Le Voltaire, Paris, Dec., 1882.) Th. Moureaux gives further account of the rising of the Seine early in December. (La Nature, Dec. 23, 1882.) W. M. D. [121 Auroras. An extensive catalogue of auroras observed in Sweden from 1800 to 1877 has been published by R. Rubenson, director of the meteorological institution of Sweden. It forms the second part of the catalogue of auroras observed since the sixteenth century. The appendix contains descriptions of the auroras, and tables of the annual variation in frequency, and the years of maxima and minima.. (Cat, aurores bor, observ. en Suède, 16th cent. — 1877, part 2.) Mr. J. Rand Capron calls attention to the fact, that the auroral display in November was followed by first a cold and then a warm wave. The doubt raised as to the character of the supposed auroral beam, which was observed in England, and from which the height of the aurora has been calculated, is removed by the statement that it gave the auroral spectrum. - Nature, Dec. 28, 1882.) w. u. [122 GEOGRAPHY. (Arctic.) Theory of an open polar sea. - Mr. George R. Howell, of the New-York state library, read a paper favoring this theory. He remarked that the field of new exploration is rapidly narrowing to that of the north polar region. Among the reasons for the opensea theory are: 10. Water-fowl go regularly each spring northward from Greenland for nesting. As the ice-barrier from 73° to 82° is too cold for birds to raise their young, their nesting-places must be north of this barrier, and in a milder climate. 2°. The occurrence of warm winds from the circumpolar regions, as verified by explorers in high latitudes. 3°. The occurrence of furious gales during the long arctic winter, which would be unaccountable if the region for ten degrees around the pole were as cold as the zone of the icebarrier, and therefore as calm as the equatorial belt. 4°. Morton and Hayes both saw open water in Kennedy channel as far as the eye could reach northward. Mr. Howell spoke of the agency of the gulf stream, which is commonly regarded as limited to the latitude of Spitzbergen. His own belief and theory is, that the waters of the gulf stream have a greater specific gravity than those surrounding the ice-barrier, for two reasons: first, the immense rain and snow fall of the arctic regions must freshen the water and make it lighter; and, second, water is lightest near the freezing-point. The comparatively warm water of the gulf stream dips and passes northward under the ice-barrier, and emerges, with velocity reduced by corresponding currents from the opposite side of the pole, into the comparatively warm polar sea. The same cause would produce an ascending current of warm air, to exert a marked influence upon the atmospheric currents of the whole northern hemisphere. Such in brief is the normal system of water and air currents, according to the theory of the speaker, whose paper was listened to with special interest. — (Albany inst.; meeting Jan. 16.) [123 Sea-otter hunting. The sea-otter hunting in the Kurile Islands, now Japanese territory, has been chiefly farmed out to foreigners as a government monopoly. It is now proposed to form a Japanese company for the purpose of carrying on the business on a larger scale than hitherto. The pelts of Enhydra marina are the most valuable furs known, and the animal is found only in the Kuriles and Alaska in any numbers. — W. H. D. [124 British co-operation in arctic meteorological and magnetic research. Letters have recently been received from Capt. H. P. Dawson, R.A., who has been appointed to undertake the work of establishing one of the chain of circumpolar observing stations in the scheme of the international commission, originally suggested by the late Lieut. C. Weyprecht. During the past summer Capt. Dawson, with two observers and an artificer, started for the Hudson Bay Territory with the idea of establishing a station at Fort Rae or Fort Providence on Great Slave Lake. Funds for the expedition to the amount of $12,500 were guaranteed by the government, $5,000 by the Royal society, and the Canadian government has since added the sum of $4,000. It is supposed that this will suffice to keep the party in the field for at least two seasons. When last heard from, all were well, though somewhat late in reaching their destination. It was not certain at last accounts whether one of the posts above mentioned, or old Fort Simpson, would be decided upon; the last-mentioned offering several advantages not shared by the others, though on some accounts less desirable. 1125 - (South America.) W. H. D. Early exploration of the Amazon. --The reprint of P. Texeira's voyage up the Amazon (1637–1638) is continued. (Bol. soc. geogr. Madrid, xiii., 1882, 266-275.) w. M. D. [126 Bolivian table-land. - The plateau southward from Lake Titicaca was explored and surveyed during a part of 1882, by J. B. Minchin, for the Bolivian government. Its altitude is 12,000 or 13,000 feet, with generally level surface, broken by isolated hills and smaller ranges. On the east, the Cordillera Real, or main chain of the Andes, is composed chiefly of stratified rocks, rising to great heights, and culminating in Sorata and Illimani. On the west, the Coast Range is largely volcanic, with some vents still active. Both ranges are metalliferous. The eastern range has copious rains and an ample plant-growth; the western is dryer and almost barren. The Desaguadero, or outlet of Lake Titicaca, flows along the eastern side of the plateau, over low, flat land, very boggy in the wet season, into Lake Poöpó or Aullagas, about 50 by 15 miles, but with low banks and variable area. From its south-western angle an outlet, the Laca-Ahuira, carries off what is not lost by evaporation. This stream flows underground for three miles of its course, and farther west is lost in the Salinas de Coipasa, which receives several other rivers, some fresh (Llauca, Isluga), some brackish (Sabaya, Cariquima): these salinas are about 400 square miles in area, and of dazzling white surface. A little to the south-east begin the great Salinas de Garcimendoza, with an area of 4,000 square miles, a white and perfectly level sheet of salt, three or four feet thick; in the dry season it can be crossed on horseback. The former area of the lake from which these salinas remain is estimated at 20,000 square miles; its old shore-line is marked by a persistent level calcareous incrustation, 200 feet above Lake Poöpó. - (Proc. geogr. soc. Lond., Nov., 1882, map.) [127 W. M. D. (Europe.) Southern Russia. — J. Garnier gives an interesting account of the region about the river Donetz, visited at the end of 1881. Rocks of the coal-measures give a gentle relief to the surface, the greatest difference found between valley and hilltop being only 150 met.; but the surrounding country is more even, a part of the great plain extending to the Arctic Ocean. The climate is consequently variable; very cold and snowy in the winter season, which begins in October. The rivers and the Sea of Azoff are frozen about four months. A quick change gives warm weather in May, and a fresh vegetation springs up; but the summers are so dry and hot that the harvests often fail. Irrigation cannot be practised, as the streams run in valleys 40 or 50 met. below the general surface. Roads are very bad, except when smoothed over with snow. The peasants pitied the French people who had some winters without snow! Towns are few, and the population is so sparse that the fields are often cultivated only once in three years. Trees are absent, except occasionally on the river-bottoms, and wood is too dear to be used for fuel. The absence of forests is the result, according to Le Play, of the severe climate; Hommaire de Hell says tree-roots cannot penetrate the compact soil; the Cossacks themselves believe the trees have been cut away and not replanted. In spite of many unfavorable conditions, years of good harvest yield immense quantities of grain for exportation. Coal forms an undeveloped resource of the country. It was discovered in the time of Peter the Great, and has lately been studied under the direction of Helmersen; but in spite of its great quantity and excellent quality, it was hardly worked till after the Crimean war; then the better steam navigation of the Black Sea, and the beginning of railroad construction in Southern Russia, gave a new impulse to mining, and in 1881 1,600,000 tons were raised. Still English coal is found in all the ports of the Black Sea. This is largely because the coal from the Donetz mines has no good harbor for export, for the Sea of Azoff is but 4 met. deep at its entrance, the Strait of Kertch; and at Taganrog, its most important port, now connected by rail with the mines, vessels drawing only 3.5 or 4 met. must anchor 25 kil. from the shore, and load or discharge by double transfer to cart and lighter. Although possible with wheat, this is too expensive for coal. The harbors might be much improved by dredging. (Bull. soc. géogr. Paris, 1882, 498.) [128 W. M. D. (Asia.) Across Eastern Gobi. Hermann Mandl, a young German, who went to try his fortunes in the East, spent two years learning Chinese at Peking, and was then engaged, in 1880, as interpreter by Gen. Zozung-tang, who was about to lead an army across the desert to Hami in view of possible difficulty with Russia concerning the occupation of Kuldja. Lieut. G. Kreitner, who had been as far as Ansifan two years before, gives a sketch-map and account of Mandl's expedition from Ansifan across Gobi to Hami, and compares it with the description of the same region in 1875 by Major Sosnowski (Journ. roy. geogr. soc. Lond., 1877, 166). Ansifan is in 95° 56' 50 long. E. of Gr., and 40° 31' N. lat., at an elevation of 1,144 met., on a fertile plain watered by the Sula-ho, which rises in the snowy Nan-san on the south, and flows westward into the desert, ending in the reported Kara-nor. The city suffered greatly in the rebellion of 1868, as did many neighboring towns, and has now only a thousand inhabitants, many of its houses being empty. Kua-Tchou, some twenty miles west-south-west, was at this time completely destroyed, though it still appears on most maps as an important place. On the 26th of July, 1880, Mandl left Ansifan. His party travelled at night to avoid the excessive heat, -the thermometer had registered 107° F. before starting, and was eleven days on the way, averaging fifty miles to a march. The loose sand of the flat desert, and the rough stony paths over the occasional hills, which sometimes rise 120 feet above the plain, made travelling extremely dif -- ficult; the resting-stations were miserable places, often supplied with bad water from their springs. A few antelope were seen on the way. Zo-zung-tang's army consisted of 2,500 men, who crossed the desert in divisions of 500 so as not to exhaust the water-supply on the way: they had not been paid for ten months, and their plundering made their advance like an enemy's invasion. But at Hami the people rejoiced at the coming of the holy general, for since his arrival it rained as it had not for a long time before. Moreover, he had posted orders that all brawlers and opium-dealers should be beheaded, all impostors should be punished with 3,000 lashes and should then have their ears bored with a lance, and he advised the people to let the soldiers have nothing till they had paid for it. Hami lies at the southern foot of the eastern extension of the Tian-san, at an elevation of 960 met., with a broad, well-watered pasture-land stretching thirty miles before it to the desert. Its population is 1,5001,800 (Sosnowski said 10,000) besides a garrison of 3,000. [On Stieler's Atlas, sheet 64, 1881, Ansifan is given as Ngansi Fan tcheu, and is placed in latitude 39° 40', or more than 50 miles too far south according to these data.] — (Peterm. mitth., 1882, 416, map.) [129 W. M. D. Russo-Persian boundary and Merv.-F. v. Stein gives a map and description of the most recent work on the region stretching eastward from the southern end of the Caspian toward the oasis of Merv. A railroad was completed in 1881 from Michailow on the Caspian, south-easterly to KysylArvat (about 130 miles); and it is now proposed to extend this along the inhabited strip of land between the Kopet Mountains and the Kara Kum (desert) to Askhabad, and perhaps to Seraks on the Tedjend (Heri-Rud river). With this object the Russian engineer Lessar has examined the route, and finds it one of very easy grades and construction, for the transition country between mountain and desert is very flat throughout. Levelling showed a depression below the level of the Caspian, about midway on the present railroad; and this is suspected to continue eastward, in which case the Tedjend and Murgab could not in former times have reached the old course of the Oxus, but must after their junction have flowed to the Caspian independently: now they are both lost in the sands of the Kara Kum. The people along the surveyed line gladly accept the present Russian and Persian government of their country, as a guard against the robbing Tekke tribes. The forts or walled towns contain a single street for the bazaars; from this, crooked, narrow, dirty alleys, often shut apart by doors, lead among the mud-huts, the only kind of habitation. In the fields at a distance from the forts, are scattered watch-towers with entrances so small that one must creep through them: the laborers hid themselves in these, blocking up the doorway, on the first appearance of a band of Tekke robbers, and there waiting till they had passed by. In the present better times, the towers are not needed. The former population must have been much larger than the present, for ruins are numerous; but the people have no traditions about their builders. Fields are cultivated only where irrigated; and on the larger rivers, Tedjend and Murgab, dams are constructed to feed numerous branching canals. The districts thus cared for have been much reduced in area in consequence of the plundering of the Tekke bands: the people have been driven off, and the canals are fallen into decay. [The question of the less supply of water is not considered.] The oasis of Merv, as described by O'Donovan, an English ‘correspondent,' contains a dense population, variously estimated from two to five hundred thousand, gathered in numerous villages, but without any central city. Since 1857, it has been in the power of the Tekke-Turcomans, who were then driven from Seraks on the Tedjend by the Persians. They are hospitable; but they are also cruel, deceitful, lying robbers. The men are poor workers; but the carpets, silks, and especially the silk embroideries, made by the women, are celebrated throughout Central Asia. The oasis is watered by the Murgab, which is raised by a dam, then divided into two arms, these into forty-eight branches, and finally into hundreds of canals: all these are under the control of the Tekke, who rent their use to the under tribes of the district. The possibility of Russian advance to this point is a question of much importance for the future of Central Asia. (Peterm. mittheil., 1882, 369, map.) [In this connection may be mentioned the accounts of Lessar's explorations in Proc. roy, geogr. soc., iv., 1882, 486; v., 1883, 1; and of O'Donovan's, id., iv., 1882, 345; and his book, The Merv oasis, London, 1882.] W. M. D. [130 BOTANY. (Structural and physiological.) New apparatus for respiration experiments. This consists of a measured flask holding upon moist paper the seedlings under examination, and connected with a supply of oxygen in a balanced eudiometer. The evolved carbonic acid is absorbed by potassic hydrate in a small receptacle suspended within to the cork of the flask. The amount of oxygen consumed can be read off on the balanced eudiometer, which sinks in a bath of mercury as its contents disappear; the carbonic acid produced is ascertained from the potassic carbonate, and from subsequent treatment of the air in the flask at the close of the trial, by means of baric hydrate. A possible objection to this apparatus is the fact, that some time must elapse after it is arranged before the temperature of the flask and eudiometer can be precisely that of the surrounding air. Professor Godlewski has, however, found this error to be in point of fact unimportant. (Bot. zeit., Nov. 24, 1882.) G. L. G. [131 G. L. G. The structure of the leaves of heath.-Ernst Ljungström divides the species of Erica into four groups depending on the shape and microscopic anatomy of the leaves. Three types are, E. cupressina, E. stricta, and Calluna vulgaris. A fourth group comprises most of the Ericae proper. (Bot. notiser, 1882, 178) G. L. G. [133 Dispersion of Utricularia intermedia. — A few plants were thrown into a swamp at Oeleghem (Belgium) where the water was shallow. By the following year the species had covered several ares. Last March, M. Gilbert observed on the surface of the water minute vesicles blown hither and thither by the winds, and so abundant in amount as to have the appearance of green velvet. These proved to be detached bulblets of Utricularia intermedia formed of whorls of rudimentary leaves on an extremely short axis (see Gray's Manual, under Utricularia). After the development of the axis the air, hitherto entangled in the leaves, escapes, and the bulblet sinks to the bottom, where it speedily develops roots. M. Gilbert notes also that this plant is also dispersed through the agency of the larvæ of caddisflies (a common bait used by anglers). The larvæ have an envelope composed of minute shells, bits of dead wood, fragments of plants, etc.; and sometimes this artificial carapace is furnished with five or six bulblets of Utricularia. These are borne about by the larvæ until at an early stage of growth they become detached from them, and then they take root in the earth at once. -(Bull. soc. roy. bot. Bely., Dec. 28, - 1882.) G. L. G. [134 Fertilization of Gerardia pedicularia. - Professor Bailey, who has already published several observations on the perforation of the flowers of this species by predatory humble-bees, has found that when few of these insects visit the flowers they are not so apt to perforate them. He concludes, with Fr. Darwin, that they only puncture flowers whose nectar they can reach normally, when competition forces them to work very rapidly. -(Amer. nat., Dec., 1882.) W. T. [135 Spring floras. - The influence of temperature has been applied by Dr. Taylor to the explanation of vernal floras. Species that bloom early are frequently identical with, or closely related to, alpine species of the same latitude; and these, as is well known, bear a similar relation to arctic species. Alpine and arctic floras are commonly explained as remnants of the post-glacial flora, which have survived in consequence of the protection afforded by the cold of high altitudes or latitudes. Spring flowers are claimed to receive similar protection by their time of flowering. It is a suggestive fact, that when our early-flowering species also occur at high elevations, or farther north, they bloom much later than with us.-(Nature, Nov. 2; Science gossip, Dec., 1882; Bot. gaz., Dec., 1882.) [136 W. T. Fall blooming of Menyanthes trifoliata. This plant was found blooming abundantly in Rhode Island on the 23d of October, by Prof. W. W. Bailey. The swamp in which it grew had been desiccated by a long summer drought, which seems to have had upon it the effect of its normal winter rest, so that the following autumn rains and continued warm weather induced a season of general and vigorous bloom. (Coult. bot. gaz., Dec., 1882.) S. W. [137 (Systematic and general.) Jamaica ferns. A critical examination of the Jamaica ferns in the herbaria of the British museum and Kew, by G. S. Jenman, results in the addition of eight new species, with some not before credited to the island, and corrections in previous determinations. (Journ. bot., Nov., 1882.) s. w. [138 New American composite.-E. L. Greene redescribes from fuller material his proposed new genus, Holozonia, intermediate between Lagophylla and Hemizonia, of a single species (H. filipes), found in mountain streamlets east of Napa Valley, California. — (Torr. bot. bull., Dec., 1882.) s. w. [139 Forest-trees of the gulf region. A similar but more detailed account of the more important foresttrees in the States bordering the Gulf of Mexico, by Dr. Charles Mohr. - (Ibid.) s. w. [140 Origin of Cassia lignea. -The cassia districts of southern China have been recently visited by Mr. Ford; and the tree which is found to be cultivated there for the supply of Chinese cinnamon, or the cassia-bark of commerce, Professor Dyer of Kew identifies with the Cinnamomum cassia of Blume. An account of its cultivation, the preparation of the bark, etc., is given. (Journ. Linn. soc. Lond., Dec., 1882.) s. w. [141 ZOOLOGY. Coelenterates. Nature of the green cells of Hydra. The ques tion whether any animals are able to produce chlorophyl is now attracting considerable attention; and as Geddes and others have stated that such animals as Hydra and Spongilla do have the power to vegetate their own intrinsic chlorophyl, Dr. Otto Hamann has made a careful examination of the manner in which the green cells make their appearance in the egg of Hydra. From the study of sections through the ovarian ovum at successive stages of development, he concludes that the green bodies are not developed in the egg, but that they make their appearance suddenly, and are full-grown as soon as they are found at all; that they migrate into the ovum, through the supporting layer from the endoderm. He thinks that the bodies which Kleinenberg described in the egg, as the early stages of the green cells, are in reality early stages in the development of the pseudo-cells. Besides examining sections, he has removed the green cells from the body of the hydra, and has cultivated them in water; and he finds that when thus treated they thrive and multiply, and are apparently under conditions of life which are as natural as those to which they are exposed in the cells of the animal. They multiply rapidly in both cases by repeated division into fours. He states, on the authority of Dr. Dalmer, that the green bodies of Spongilla and Paramarcium also multiply by division into fours, and that they will thrive and multiply, like those of Hydra, in water. From these reasons, as well as from the fact that they are not formed by the egg of Hydra, but migrate into it, and from the fact that they have a cell-wall and nucleus, he concludes that they are algae; and he therefore accepts Brandt's conclusion, that, in every case where chlorophyl is present in animals, we have to do with unicellular algae, which are both morphologically and physiologically independent. Brandt's statement that a green Hydra, when placed among specimens of the brown Hydra, inoculates them with its alga, and thus converts them into its own species, he disputes, on the ground that his own experiments in this direction failed, and also for the reason that the two forms are distinguished by many specific characteristics which have nothing to do with the presence or absence of the green bodies.. He also doubts the propriety of giving specific names to these algae at present. As regards the relation between the alga and its host, he believes that the Hydra derives no particular benefit from the oxygen given off by the algae, although it may digest them. He does not regard the alga as in any way dependent upon the Hydra. (Zeitschr. wiss. zool., xxxvii. 457.) A directly opposite view regarding the nature of the green bodies of Hydra is advocated by William Marshall, who concludes, from the fact that they remained without change in a Hydra which was kept in the dark for six weeks, that they are not algae but are characteristic of the animal itself. He regards the green color of Hydra viridis as a protective resemblance to the fresh green plants among which it lives. -(Ibid. 665.) W. K. B. [142 Interesting observations on Hydra viridis. — The paper last noticed contains a number of facts regarding this species, which, although they are not strictly new, have never received due attention. Marshall has verified Baker's observation, made 140 years ago, that, when a parent Hydra is injured, one of the |