Imagens das páginas

the winter, Mr. Jaines McNab, curator of [the Royal Botanical Gardens, delivered an address on the change of climate in Scotland, Which, during the last fifty years has undergone a considerable lessening of the summer heat. From this cause ■peaches and nectarines cannot be ripened to the same perfection in the open air as formerly, while asparagus, mushrooms, and tomatoes are gradually disappearing. The larch, in spite of the enormous quantities of seed annually imported, if declining in vigour, and there is a talk of substituting for is the Wellingtonia as a nurse-tree. Mr. McNab proposes that a central committee should be appointed to investigate the whole subject of the change of climate in Scotland.

The following is an ephemeris (for 0*1 Berlin time) of the comet discovered by M. Coggia at Marseilles, on the evening of the 10th inst: — November 22, I4h 51° 25s—6" 8'-2; ^November 30, 1411 I4m 305—22° 43''o; December 8, I4h o"'l7s — 32° i'.8. Its elements are:—T = Dec, 4-1348, Berlin mean ftme ; x =94° 23' 14"; S = 254° 14' 9" ; i = 27° 2' 7". Mean Equinox, 1873-0 log. q. = 9-83810.

■ONEof the special results of the United States geological and geographical survey of the Territories, in chargeof Prof. F.V. Hayden. •during the past summer, has been the discovery that Colorado Territory is the centre of the greatest elevation of the Rocky Mountain chain. In Central Colorado the chain proper is about 120 miles broad, made up of three lofty parallel ranges, running nearly north-north-west, and flanked from the west by great plateaus and groups of peaks. Between the ranges lie the great elevated basins known as "parks." The front range, which rises abruptly from the plains, is seen from Denver in a grand panorama 120 miles long. From its snowy serrated crest rise ■many peaks between 13,000 and 14,000 ft. high. On the -west side of the parks is the Park Range, whose highest group is at Mount Lincoln, this and Quandary Peak each rising to about 14,000 ft. The survey has established a permanent meteorological station at Fairplay, 10,000 ft. above the sea, and another at Canon City, about 6,000 ft. These stations are all connected by a spirit-level line, and the comparison •of their observations will be of remarkable interest. The National Range lies east of the Park Range, and is separated from it by the Arkansas Valley. West of the National Range rises the great group of Elk Mountains, five of whose peaks are 14,000 ft. high. So far as known, there are in the district explored during the past season by the survey 72 peaks, ranging from 14,000 to 14,200 ft. in height.

In the article on Local Societies (vol. ix. p. 24) we inadvertently confounded the Manchester Natural History Society with the Microscopical and Natural History section of the Manchester Literary and Philosophical Society. The former of these is extinct—having handed its collections over to the Owens College—and also contributed a handsome sum of money to promote, permanently, the study of Natural History in the Literary and Philosophical Society. This endowment now enriches the Natural History section of that society. Manchester science will gain rather than lose by these changes. The defunct society was never more than the creator and guardian of a museum. That museum will still be preserved and increased, as well as utili-ed, by the College, whilst the Natural History section affords promise of a healthy career of scientific woik.

M. Ciiarsel, of Marseilles, writes as follows to the Bulletin International, of the Observatory of Paris, on the invention of balloons :—In the literary history of the City of Lyons, published by Father Colonuia (1830, vol. i. p. 112), it is stated that in the reign of Louis le Debonnaire, the Archbishop of Lyons learned that some aerial navigators had fallen with their boat on the banks of the Saone, and were going to be put to death as sor

cerers. He ordered them to be brought into bis presence, and after having heard them, he caused them to be nonsuited {It fit mttlrt hors deproch). The memoir of the prelate bears such a character of authenticity as leaves no doubt of the fact The following words are taken verbatim from the memoir: "Videmns exhibere vinctos quatuor homines; tres viros et unam feminam, quasi qui de ipsis navibus ceciderunt, quos . . . exhibuemnt m nostra presentia tanquani lapidandos." It follow*, then, from this memoir, that already, in the ninth century, aerial navigation was known ; how it was accomplished the memoir does not give any indication.

The first Annual Exhibition of the West London Eniooiological Society, established 1S68, will be held on Deceml>er 2 and 3, at the "Mason's Arms," Tichliorne Street, Edgware Road.

A Times telegram from Teheran, November 34, says that Colonel Baker and Lieutenant Gill have arrived at Teheran, and leave immediately for England, inii Tabreez and Erivan. Travelling to the north from Meshed, they passed along the Turcoman frontier by Kelat, Abiverd, Dereguez, Annau, Astrabad, and Nissa. Striking south, they discovered the source of the Attrek at Karakazan, an extraordinary spring near Shirvan, and followed the course of the river ( a considerable distance north* west of Bojnoord, until stopped by hostilities between Bojnoord and the Turcomans. Striking into the mountains, they were enabled to trace the course of the river until it fell into the plains, and also to observe the great range of mountains which runs along the whole Persian frontier from Sarakhs to Kiril Arvat. Existing conjectural maps of this country are quite incorrect.

On the 1st inst. the Earl of Dalhousie formally opened the Art Exhibition and Museum of the Albert Institute" of Dundee, which, with the previously opened portions— free library and lecture-hall — form one handsome block of buildings. In the list of towns, with their scientific societies, published by us a week or two ago, we were surprised to see Dundee, so rapidly advancing in population and wealth, occupy so humble a place. We cannot see how towns like Leeds, Newcastle, Manchester, Glasgow, and others should have their flourishing and well-equipped scientific societies, while Dundee has only one small struggling society of young men, the Naturalists' Field Club. The neighbouring and comparatively stagnant town of Perth, with its large and efficient society, puts Dundee to the blush in this respect. We shall be disappointed if the opening of the Albert Institute in Dundee, a town so dependent for its commercial and manufacturing success on the applied results of Science, does not give an impetus to the study of Science. There are already Science and Art Classes in the town, and we hope to hear soon of the establishment of regular courses of scientific lectures, such as those which are found in several of the large English manufacturing towns, and the formation of at least one flourishing scientific society and field club around the small nucleus already existing. We hope also that the collections in the museum will be made worthy of the wealthy town and be really representative of the treasures of the various kingdoms of Nature. We feel sure that the citizens of Dundee only need their attention to be drawn to the backward state of their town in the matter referred to to rouse them to put it on a level in this respect with the large English towns.

The additions to the Zoological Society's collection during the last week include an Eagle (Spisaelus ?) from Burmah, presented by Mr. H. Fielder; a Macaque Monkey (Maeaau cfitomolgus) from India, presented by Mr. Gore; a pair of Jaguars (Felis onea) bom in the Jardin des Piantes, Paris, received in exchange. ,



I.—Mitraria /"\NLY a tingle specimen was obtained of the little Mitraria, ^"^ which formed the subject of the present communication, and neither its structure nor development was made out as completely as could have been wished. From the Mediterranean species described in a former communication (British Association Report for 1872), it diners in some points of structure and in the mode of annnlation of the developing worm. It possesses the usual Mitraria form, that of a hemispherical dome having its base encircled by a band of long vibratfle cilia. In the.side of the dome a little above the ciliated band is the mouth which leads into a rather wide pharynx clothed with a ciliated epithelium. The pharynx runs through the dome parallel to its base and opens into a capacious stomach which continues in the same direction until it joins the intestine. This then turns down abruptly at right angles to the previous portion of the alimentary canal, and then projects for a slight distance beyond the base of the dome, carrying with it hernia-like the walls of the base.

The true body walls of the future worm, of which the Mitraria is the larva, seem as yet confined to the intestinal segment of the alimentary «ml They already present the commencement of annulation, which, however, exists only on the dorsal and ventral sides, while two broad bands of very distinct fibres may be seen, one on the right and the other on the left side, extending transversely from the dorsal to the ventral surface.

The ciliated band which runs round the base of the dome possesses a rather complex structure. It consists of two concentric rings: an outer one composed of large oval distinctly nucleated cells, and an inner one of a granular structure and yellowish colour, in which no distinct cells could be demonstrated. The cilia form two concentric wreaths borne by the under side of the band, an outer wreath consisting of very long cilia, and borne by the inner edge of the outer portion of the band, and an inner wreath of much shorter cilia borne by the inner edge of the inner portion. The band with its cilia is interrupted for a very short space at the aboral side of the dome. There is probably at this spot an entrance into a watervascular system. No such system, however, was observed in the specimen, though the author had described in another species of Mitraria a system of sinuses which appear to exist in the walls of the dome, and which he regarded as representing^? watervascular system (Brit. Assoc Report for 1872).

Occupying the very summit of the dome is a large, somewhat quadrilateral ganglion, from which two distinct filaments are sent down, one on each side of the alimentary canal, but he was not able to follow these filaments to their destination. The bilateral symmetry of the ganglion suggests its formation out of two lateral halves. Though its very superficial position gives it the appearance of being a mere thickening of the walls, the view here taken of its being a nervous ganglion seems to be the only one consistent with its relations to the surrounding parts.

On each side of the pharynx, a little behind the mouth, is a small oval ganglion-like body from which a filament runs to the ciliated band. Some delicate filaments may also be seen lying between the pharynx and the walls of the dome on which they seem to be distributed, but the author could not trace them to any distinct ganglionic centre.

The great apical ganglion carries two very obvious black ocelliform spots, and besides these two clear vesicles enclosing each a clear spherical corpuscle. The two vesicles may probably be regarded as auditory capsules.

The further development of this larval form has not been observed. It probably consists chiefly in the continued prolongation of the alimentary canal beyond the base of the hemispherical dome, the completion of the annulation by its extension to the right and left sides, and the gradual contraction of the dome and final absorption of the ciliated band.

2.— Tornaria Two specimens of the larval form originally discovered by Johann Muller, and described by him under the name of Tornaria, were obtained, but these unfortunately perished before a sufficiently exhaustive examination of them could be made. On the whole their structure agrees closely with what has been

[merged small][ocr errors][ocr errors]

pointed out by Alex. Agassiz in his valuable and elaborate memoir on Tornaria and Balanoglossus. The species appears to be different from those hitherto described. The gills had not begun to show themselves, and there were but traces of the "lappets" described in other species as appended to the posterior extremity of the stomach.

The author believed that he could distinguish a minute ganglion on each side of the oesophagus ; filaments were sent off from it to the neighbouring parts, and the two were connected to one another by a sub-cesophagal commisure. The water-vascular chamber was very distinct, but the so-called heart was not observed ; while within the body-cavity, lying close to the dorsa pore and over the canal by which the great water-sac communicates with the external medium, was a small, closed, rather thick-walled vesicle containing numerous oval corpuscles. Of the nature of this vesicle the author could not offer any opinion.

The cushion-like body which occupies the summit of the larva exactly as in Mitraria, and supports the two ocelliform spots, was very distinct, and so also was the contractile chord which extends from this to the walls of the water-sac. The author, however, could not here, any more than in Mitraria, regard the cushion-like body as a mere thickening of the walls; he believed it to be a nerve-mass, and thought he could trace two fine filaments proceeding from' it and running down, one towards the right and the other towards the left side of the alimentary canal, but he was not able to follow them for any distance, and he does not regard their existence as confirmed. The extremely superficial situation of this body, which makes it resemble a mere thickness of the walls, is paralleled by that of the great ventral nerve-mass in Sagitta.

The contractile chord which runs to the water-sac is probably attached to a capsular covering of the ganglion, rather than directly to the ganglion itself. This chord, though showing strong contractions by which the summit of the larva is drawn down towards the water-sac, is of a homogeneous structure, presenting no appearance of distinct fibrillar or of other contractile elements.

The author instituted a comparison between Tornaria and Mitraria. We have in both the external transparent pyramidal or dome-shaped body, with a lateral oral orifice, and a basal anal orifice, enclosing an alimentary canal which is divisible into three regions, and takes a partly horizontal and partly vertical direction in its course from one orifice to the other;" we have in both, near the base of the body, the circular band which carries long vibratile cilia accompanied by a row of pigment spots, and in both the cushion-like ganglion carrying ocelli.

From Mitraria, Tornaria chiefly differs in the presence of the thick sinuous and convoluted bands which give it so close a resemblance to certain Echinoderm larvae, and which are entirely absent from Mitraria, and in its water-vascular system with the contractile cord which extends from this to the apical ganglion. If a water-vascular system is present in Mitraria, it consists there of a system of sinuses excavated in the walls of the dome, but without any representative of the great central sac In Mitraria the great apical ganglion carries not only the two ocelli, but also two capsules, probably auditory; these capsules do not exist in Tornaria. In Mitraria the two nerve chords which the apical ganglion sends down one on each side of the alimentary .canal are very distinct; in Tornaria, if they exist at all, they are by no means obvious. Finally, the ciliary circlet is simple in Tornaria, while in Mitraria it is double.

According to Alexander Agassiz's account of the development of Tornaria into Balanoglossus, the great transverse circlet of cilia becomes, by the elongation of the body, gradually pushed backwards, so as to form the anal ciliated ring of the young worm ; in Mitraria the great ciliary circlet remains unchanged in position, and is probably ultimately absorbed, the worm during its development acquiring a new anal wreath of cilia.

3. Anutrangia htmispherua (nov. gen. et spec.) Among the most abundant products of the towing-net was a little hydroid medusa, remarkable for the want of symmetry in the distribution of its gastro-vascular canals. It is of a hemispherical form, with the base about hall-an-inch in diameter, and provided with very numerous (more than 100) marginal tentacles, which arc very extensile, and may at one time be seen floating away to a length of three or four inches and at another coiled into a close spiral against the margin of the umbrella.

* In the species of Mitraria described by J. Muller and by MetschnikcfT, both oral and anal orifices are basal, and the alimentary canal presents a 1 thaped curvature

Each tentacle originates in a bulbous base with a distinct ocellus. No lithocysts are visible on the margin. The velum is of moderate width.

The manubrium forms a small projection from the summit of the umbrella, and terminates in four rather indistinct lips. From the base of the manubrium three rather wide onsets are sent off at equal intervals into the walls of the umbrella. These gradually contract in diameter, and then, as three narrow tubes of uniform diameter, run towards the margin, where they open into the circular canal. The symmetry of the radiating canals is confined to these three primary trunks. From their wide proximal ends each sends off branches, some of which may be traced to the margin where, like the three primary canals, they enter the circular canal, while others can be followed for various distances in the umbrella walls, in which they terminate by blind extremities without ever reaching the margin. These branches are very irregular in the number sent off from each primary canal, as well as in their length and directions.

The generative elements are formed in oval sporosacs developed one on each of the three primary canals at the spot where the wider base passes into its narrower continuation. The ova may be seen within them in various stages of development; they increase considerably in size before the commencement of segmentation, always showing up to that period a large and distinct germinal vesicle with germinal spot and with a distinct nucleolus in the interior of the germinal spot. The development of the ovum proceeds within the sporosac to the segmentation of the vitellus and the formation of the planula, which now breaks through the outer walls of the sporosac and remains for some time adhering to their external surface. The planula differs remarkably from the typical hydroid planula. It remains of a nearly spherical form, never acquiring cilia, and possesses little or no power of locomotion. The gastric cavity, however, is fully formed. The author was unable to follow the ova in their further development.

The little medusa now described, departs in several important points from the typical hydroid medusa. From this it diners in the ternary disposition of the primary radiating canals, and in the irregular non-symmetrical arrangement of those which are subsequently formed. Among the very many specimens examined, the author never found any in which the canals had become regular in their disposition, even in those which had discharged the contents of their sporosacs, and had evidently attained the term of their existence. It differs also from the typical medusa in the form and non-ciliated condition of the planula; and still further in the fact that while the generative elements are borne on sporosacs, developed on the radiating canals, the marginal bodies are ocelli and not lithocyst.

4.—Circe invcrtens (nov. spec.)

Among the hydroid medusas captured in the towing-net, were two or three specimens of a species referable to the genus Circe of Mertcns. It measures about half-an-inch in its vertical diameter, and about a quarter of an inch transversely. It is cylindrical from its base upwards, for about two-thirds of its height, and then contracts abruptly, and arches dome-like towards the truncated summit, which is surmounted by a solid cone of the gelatinous umbrella substance. From the summit of the umbrella-cavity, a solid somewhat fusiform extension of the roof hangs down in the axis of its cavity for about two-thirds of its depth, and at its free end carries the manubrium, which extends nearly to the codonostome. The margin of the umbrella carried eighty very short and but slightly extensile tentacles, which were connected at their bases by a very narrow membraneous extension of the margin, with rather irregular free-edge. Lithocysts are situated at irregular intervals upon the margin. There are about sixteen of them; they consist each of a minute spherical vesicle with a single large spherical concretion. There are no ocelli. There is a moderately wide velum.

The radiating canals are eight in number. They spring from the base of the manubrium, run up the sides of the solid process which hangs from the summit of the umbrella; pass from this to the walls of the umbrella, and then run down towards the margin in order to open into the circular canal.

The generative elements are borne in pendent sporosacs, which spring from the radiating canals close to the summit of the umbrella cavity.

The motion of the medusa takes place by means of sudden jerks, reminding us of the way in which certain Diphydse dart through the water.

The medusa possesses also a very singular habit of partial inversion. This takes place alony the line which separates the dome-like portion of the umbrella cavity from the lower cylindrical portion, and cunsists in the withdrawal of this dome-like summit and the lower portion ol the cavity. When thus inverted the little animal presents a drum-shaped form, with the manubrium hanging far out of the codonostorae.

Alexander Agassiz considers the genus Cine, ai Merteof, as synonymous with Trachynema Gegenbaur, and points out thai the name of Circe had been already used for a genus of mollu&ca, He further removes it from among the true hydroid medusae, and regarding it as closely allied to the -iL^iHid.e, places it along with those in the HaploiU<mea Agassiz, a sub-order of the ZH:cophora.

The author, however, could not see sufficient grounds for the removal of Mertens' genus from the true Hvdrvida, with which the medusa now described agrees in all essential points, includingthe form and disposition of the gaslro-vascular and generative systems and the structure of the marginal lithocysts. Neither could he agree with Alexander Agasaiz in identifying it with, Trachyntma. The greatly developed solid peduncle by which the manubrium in Circe is suspended from the summit of the umbrella-cavity in a way, however, which has its parallel in 7im.i among others, is of itself a character of generic importance by which Circe must be kept apart from Trachynema. It is true that Gegenbaur's Trachynema has the character of a young form, and until we have further evidence of its adult state its amnitua cannot be regarded as established.

Gegenbaur believes that he has established the direct development of Trachynema from the egg without the intervention of a hydriform trophosome, but unfortunately we have no data by which to compare in this respect Circe with Trachynema.

It must be admitted too that in the Imperfect contractility of the marginal tentacles and in the somewhat greater firmness of the umbrella walls the little medusa described in the present communication possesses characters which look towards the sEsinid<e, but these are by no means sufficiently strong to justify its separation from the ordinary hydroid medusae.

5. — Tomopteris

A few young specimens of this beautiful little worm were obtained, and the author was enabled to confirm the statements of Grube and of Keferstein, who describe in it a double ventral nerve chord, though other observers have failed to discover this part of the neivous system and throw doubt upon its existence. In adult specimens examined some years previously by the author no ventral chord could be detected.

The ventral portion of the nervous system consists of two flat ribbon-shaped chords which are given olT from the inferior side of the nerve ring which surrounds the pharynx just behind the mouth. These run parallel to one another, separated by a narrow interval; they lie on the ventral walls of the animal, and may be traced through the narrow taillike termination of the body xs far as its extremity. They present no ganglionic swellings, but opposite to every pair of feet each sends off a filament which passes to the foot of its own side in which it is distributed.

Dr. Anton Dohm has just informed the author that he too had distinctly seen the ventral chord of Tomopteris.


Amongst the papers in the October and November numbers of the American Naturalist, are included Dr. J. L. Smith's Address to the American Association for the Advancement of Science, on Science in America and Modern Methods of Science. —Mr. R. Ridgway describes some new forms of American Birds, which he considers as geographical races, and not distinct species. Included are Catherpes ntcxicanits, var. conspersus j Helminihophaga celala, var. lulescais; Dendr erica vieiiiotii, var. bryanti; D. dominica, var. albilora; D. gratia, var. decora; Myiodioctcspusillus, var.pileolata (Palhs), and Coilurio ludcnicianiis, var. robustus (Baird), which are described and followed by a synopsis of the genera of Certhiola, Juiico, and Cardimilis.— Prof. C. A. Riley has a paper on the Oviposition of the Yucca Moth, in which he shows that the female conveys her eggs into the young fruit by a lateral puncture. The Structure and Growth of Domesticated Animals, forms the subject of a popular lecture by Prof. Agassi*, which is followed by one on Staurolite

Crystals and Green Mountain Gneisses of the Silurian Age, by Prof. Dana.—The Rev. D. T. Hill gives instances of intelligence in Bufo americanus.— Mr. G. W. Morehouse analyses the structure of the scales of Lepisma saeckarina.—Mr. D. Scott gives a popular explanation of the differences between the two genera of North American Goatsuckers, the Whippoorwills (Antrvstomut), and the Nighthawks [Chordeiles), which is followed by a short note from Mr. Packard, jun., on the Embryology of Lin-.ulus, with remarks on its affinities. His results are confirmatory of those of M. Alphonse Milne-Edwards.

The fourth and concluding part of vol. xxviii. of the Transactions of the Linnean Society, is chiefly occupied by a supplementary paper by the Rev. O. P. Cambridge, on New and Rare British Spiders; but also contains some short papers of importance.—I'rof. Oliver describes a new genus of Begoniacex' from New Granada, under the name of Begoniella, a monotypic genus of great interest as respects the geographical distribution of the order; and three new genera of Malayan plants from the herbarium of Dr. Maingay—Ptcleocarpa and Ctenolophon (Olacine*), and Afaingaya (Hamamelidea;).— Dr. M'Nab publishes his important paper on the Development of the flowers of Wehoilschia mtrabilis. Dr. M'Xab considers that in the male flowers of this very remarkable plant we have a very close approach to the Angiosperms, the axis of the flower ending in a mass of tissue which, in the female flower, is the terminal ovule; while, in the femile flower, we have the truly gymnnspermous condition, there being no carpels, but a terminal ovule, the modified end of the axis of the flower, with a single ovular integument, the pollen grains being applied directly to the naked nucleus.


Royal Society, Nov. 20.—"Note on the Electrical Phenomena which accompany irritati m of the leaf of Diomta muscipula," by Dr. J. Burdon Sanderson, F. R.S.

1. When the opposite ends of a living leaf of Diotuza are placed on non-polarisable electrodes in metallic connection with each other, and a Thomson's reflecting galvanometer of high resistance is introduced into the circuit thus formed, a deflection is observed which indicates the existence of a current from the proximal to the distal end of the leaf. This current I call the normal leaf-current. If, instead of the leaf, the leaf stalk is placed on the electrodes (the leaf remaining united to it) in such a way that the extreme end of the stalk rests on one electrode and a part of the stalk at a certain distance from the leaf on the other, a current is indicated which is opposed to that in the leaf. This I call the stalk-current. To demonstrate these two currents, it is not necessary to expose any cut surface to the electrodes.

2. In a leaf with the petiole attached, the strength of the current is determined by the length of the petiole cut off with the leaf, in such a way that the shorter the petiole the greater is the deflection. Thus in a leaf with a petiole an inch long I observed a deflection of 40. I then cut off half, then half the remainder, and so on. After these successive amputations, the deflections were respectively 50, 65, 90, 120. If in this experiment, instead of completely severing the leaf at each time, it is merely all but divided with a sharp knife, the cut surfaces remaining in accurate aprwsition, the result is exactly the same as if the severance were complete ; no further effect is obtained on separating the parts.

3. Effect of constant current directed through the petiole on the leaf-current.—If the leaf is placed on the galvanometer electrodes as before, and the petiole introduced into the circuit of a small Daniel], a commutator being interposed, it is found that on directing the battery-current down the petiole [i.e., Jrom the leaf), the normal deflection is increased ; on directing the current towards the leaf, the deflection is diminished.

4. Negative variation.—a. If, the leaf being so placed on the electrodes that the normal leaf-current is indicated by a deflection leftwards, a fly is allowed to creep into it, it is observed that the moment the tly reaches the interior (so as to touch the sensitive hairs on the upper surface of the lamina), the needle swings to the right, the leaf at the same time closing on the fly.

b. The fly having been caught does not remain quiet in the leaf; each time it moves the needle again swings to the right, always coming to rest in a position somewhat farther to the left than before, and then slowly resuming its previous position.

c. The same series of phenomena present themselves if the

sensitive hairs of a still expanded leaf are touched with a camelhair pencil.

d. If the closed leaf is gently pinched with a pair of forceps with cork points, the effect is the same.

e. If the leaf-stalk is placed on the electrodes, as before, with the leaf attached to it, the deflection of the needle due to the stalk-current is increased whenever the leaf is irritated in any of the ways above described.

f. If half the lamina is cut off and the remainder placed on the electrodes, and that part of the concave surface at which the sensitive hairs are situated is touched with a camel-hair pencil, the needle swiogs to the right as before.

g. If, the open leaf having been placed on the galvanometer electrodes as in a, one of the concave surfaces is pierced with a pair of pointed platinum electrodes iu connection with the opposite ends of the secondary coil of a Du Bois-Reymond's induction apparatus, it is observed that each time that the secondary circuit is closed, the needle swings to the right, at once resuming its former position in the same manner as after mechanical irritation. No difference in the effect is observable when the direction of the induced current is reversed. The observation may be repeated any number of times, but no effect is produced unless an interval of from ten to twenty seconds has elapsed since the preceding irritation.

h. If the part of the concave surface of the leaf which is nearest the petiole is excited, whether electrically or mechanically, the swing to the right (negative variation) is always preceded by a momentary jerk of the needle to the left, i.e. in the direction of the deflection due to the normal leaf-current; if any other part of the concave surface is irritated, this does not take place.

«'. Whether the leaf is excited mechanically or electrically, an interval of from a quarter to a third of a second intervenes between the act of irritation and the negative variation.

"On the Algebraical Analogues of Logical Relations," by Alexander J. Ellis F.R.S.

The object of this paper is to examine the "mathematical theory of logic," thus laid down by Dr. George Boole in his "Laws of 1 hought," p. 37 :—" Let us conceive of an Algebra in which the symbols .1, y, ;, &c. admit indifferently 01 the values o and 1, and of these values alone. The laws, (he ax oms, and the processes of such an algebra will be identical in their whole extent with the laws, the axioms, and the processes of an Algebra or Logic. Difference of interpretation will alone divide them." For this purpose, first the laws of such an algebra have been investigated independently of logic, and secondly the laws of primary and secondary logical propositions as laid down by Dr. Boole, have been developed in an algebraical form, and compared with the former. The main results presumed to be established are :—

1. That there is a fundamental difference between such an algebra and logic, inasmuch as the algebra admits of only two phases, o and 1, and logic admits of three phases, namely, not only none and all, corresponding to o and I, but also some, "which, though it may include in its meaning all, does not include none" (ibid, p. 124), and hence has no analogue in such an algebra; that is, an algebra of o and 1 can correspond only to a logic of none and all.

2. That, notwithstanding this difference, there are certain formal relations of equations which allow the algebra of o and I to be used as an algorithm for the purpose of arriving at certain logical forms, which, however, have then to be interpreted on a basis which has not even any analogy to the algebraical.

3. That the introduction of this algorithm introduces theoretical difficulties, adds to the amount of work, and is entirely unnecessary even for the purposes of the theory of probabilities founded upon it by Dr. Boole.

Mathematical Society, Nov. 13.—Prof. Cayley, and subsequently Prof. Sylvester, in the chair.—The following gentlemen have been elected officers of the new council:—President, Dr. Hirst; Vice-Presidents, Prof. Cayley, and Messrs. Spottiswoode and Sylvester. The retiring members were Prof. Crofton and Mr. J. Stirling, in whose room Mr. Sylvester and Lord Rayleigh were elected.—Mr. Sylvester then gave a description of a new instrument for converting circular into general rectilinear motion and into motion in conies and other plane curves. (A brief sketch of the historical aspect of the communication, from the pen of Mr. Sylvester, forms the subject of a paragraph in Nature of Nov. 13.) Several instruments were placed on the table for inspection.—Mr. W. Marsham Adams exhibited his Mensurator and Cxlometer, and gave a short account of the objects to which they could be applied. The Mensurator is an instrument designed primarily for the instantaneous solution of triangles, but capable, from its construction, of many other uses; such as illustrating most of Euclid's theorems with regard to the triangle, of performing addition, subtraction, rule of three, and extraction of square roots, of solving quadratics and simple binomial equations, and of reducing to mechanism some part of analytical geometry. The Cyclometer is an apparatus consisting of a stand carrying a globe mounted somewhat like a sea compass, and illustrates celestial longitude and latitude, the phenomena of the seasons, the correspondence of the calendar with the solar year, the precession of the equinoxes, the times of sunrise at any place on any day, the position of the principal stars during the night, and the general relations between the conceptions necessary for nautical astronomy. Medals were awarded for both instruments at the Vienna Exhibition. —Mr. S. Roberts (treasurer) read a short note "On the expression of the: ;of a Cartesian by elliptic functions." The author showed that the hyper-elliptic part of the integral which gives the value of an arc of a Cartesian, is reducible to the form which Jacobi has shown to depend on elliptic functions.

Zoological Society, Nov. 19.—Dr. A. Gunlher, F.R.S., vice-president, in the chair. Mr. Sclater exhibited and pointed out the characters of two new species of birds obtained by Mr. Salmon during his expedition to the State of Antioquia, Columbia. These were named Chlorochrysa nitidissima and Grallaria ruficeps.—A letter was read from Mr. R. Swinhoe, H.B.M, Consul at Chefoo, containing a note on the White Stork of China, and stating that he had recently obtained a live Pitta in China, which appeared to be Pitta nympha of the Fauna Japonica.—Mr. A. H. Garrod exhibited and pointed out certain peculiarities in the oecum of a Crab-eating Fox {Cam's cancrivarus).—Mr. Sclater exhibited and made remarks on a pair of horns of the new Bubaline Antelope from the Bogos country, lately named Alcelaphus lora by Dr. Gray.—A paper was sent by Dr. Edward L. Moss, Surgeon in charge R.N. Hospital at Esquimalt, on a singular Virgularian Actinozoon taken at Burrard's Inlet, close to the northern mouth of the Fraser River.— A communication was read from Dr. O. Finsch, containing the description of a most remarkable and interesting new Passerine Bird which he had received from Mr. T. Klinesmith of Levuka, Ovalou, Feejee Islands. This little bird, which was not only new as a species, but also the type of a new genus, he proposed to call Lamprolia Vutoruc.—A communication was read from Mr. W. S. Atkinson, of Darjeeling, containing the descriptions of two new species of Butterflies from the Andaman Islands, which were named respectively Papilio mayo and Euplcca andamanensis.—Dr. Cobbold communicated the first of a series of papers entitled "Notes on the Entozoa;" being observations based on the examination of rare or otherwise valuable specimens contributed at intervals by Messrs. Charles Darwin, Robert Swinhoe, Charles W. Devis, the late Dr. W. C. Pechey, Dr. Murie, and others.—Mr. Edwin Ward exhibited and gave the description of a new Bird of Paradise, of the genus Epimachus, which he proposed to call E. el hoti.—A communication was read from Surgeon-Major Francis Day, containing remarks on Indian Fishes, mostly copied from the original manuscripts of the late Dr. Hamilton Buchanan.—Mr. J. W. Clark read a memoir on the Eared Seals of the Auckland Islands, one of which he recognised as Otaria hookeri, thus fixing the locality of this species.

Linnean Society, Nov. 20.—Mr. G. Bentham, president, in the chair.—Prof. Dyer exhibited a specimen of the fruit of Luffa cegyptiaca, a gigantic species of gourd, grown in this country.— An account of the flora of Monte Argentaro, on the borders of Tuscany, by Mr. Henry Groves, of Florence, was read.—On the Alga: of Mauritius, by Dr. Dickie. The total number of species recorded is 155. These include 17 well-known European species, most of which are cosmopolitan; 23 South African species; 12 Australian; 15 East Indian; 14 species found in the Red Sea; 12 being peculiar to the island.—On a peculiar embryo of Delphinium, by the Rev. C. A. Johns. The interesting point in the structure was the non-separation of the two cotyledons, the plumule forcing itself through a chink in the undivided cotyledon. Dr. Masters stated that this peculiarity is well known to occur occasionally in Ranunculacea:, as well as in some other plants.— On the buds of Malaxis, by Dr. Dickie. This is supplementary to the paper already published in the "Journal" of the Society. —On the Alga; of St. Thomas and Bermuda, by Mr. H. N.

Moseley. These were the results of the explorations on board the Challenger, one marine flowering plant being also found 10 flower for the first time.

Chemical Society, Nov. 20.—Dr. Odling, F.R.S., president, in the chair.—A paper on "the coefficient of expansion nf carbon disulphide," by J. B. Hannay, was read by the secretary. —Dr. Russell then communicated his researches on the action of hydrogen on silver nitrate, giving an account of the precipitation of metallic silver in the crystalline state by means of hydroya. —There were also a note on the action oi zinc chloride on codeine, by Dr. C. R. A. Wright; on the chemical properties of ammoniated ammonia nitrate, by E. Divers, M.D.; and on the analysis of a meteoric stone and the detection of vanadium in it, by R. Apjohn.


Academy of Sciences, Nov. 17.—M de Quatrcfagcs. president, in the chair.—The following papers were read. —An answer to M. Tarry'a remarks on the theory of the sun's spots, by M. Faye. M. Tarry's objection to M. Faye' theory was that, instead of a down-rush, he ought to have employed an up-rush as the cause of the spots, as a terrestrial cyclone rushes up, and not down. M. Faye answered the objections in detail.—Second memoir on the way in which water intervenes in chemical reactions, and on the connection between electro-motive force and affinity, by M. Becquerel.—Studies on beer; a new method of brewing it and rendering it unchangeable, by M. L. Pasteur. The author considers the spoiling and souring of beer to be due to germs, and suggests methods for preventing their access or destroying them during the processes of brewing.—An answer to M. Oudemans' observations on the influence of refraction, &c, during the transit of Venus, by M. E. Dubois.—On the use of the prism for the verification of the law of double refraction, by Prof. G. G. Stoke?,—On certain metallic spectra (lead, chloride of gold, thallium, and lithium) by M. Lecocq de Boisbaudran. The author found that the combination of a metal was attended with the loss of some of the lines it exhibited when in the free state.—On the maximum density of water, by M. Piarron de Mondesir.—On the cooling effects of the joint actions of capillarity and evaporation, by M. C. Decharme.—On the quantity of ammonia contained in atmospheric air at different altitudes, by M. TruchoL The author stated that the ammonia increases as the cloud region is approached, and gave tables of determinations in support of his views.—Remarks on the paper of Pelouze and Audouin on the condensation of liquifiable matters held in suspension by gases, by M.D. Colladon.—Remarks on the paper of M. Derbes on the Pemphigus of Pistacia tcrebinthus compared with the Phylloxera ouereih, by M. BalbianL—On the swellings produced on vine rootlets by the Phyllaxera, by M. Max. Cornu.—On triple planes tangent to a surface, by Mr. W. Spottiswoode.—On the direction of the propagation of electricity, by M. Meyreneuf.—An answer to M. Mercadier's last note on the study of the vibratory movements of an elastic wire, by M. H. Valerius.—Observations on the molecular structure of meteoric iron and on solid ferrous chloride in meteorites, by Mr. J. Laurence Smith.—On the tertiary supranummulitic formations of the department of Herault, by M. Rouville.—The death of M. CL Burdin, correspondent of the mechanical section, was announced.

[blocks in formation]

The Southern Uplands or Scotland, II. By Prof. R. Harknrss,

F.R.S. .S7

Levbold's Excursion To The Argbntinb Pampas 59

A Hkalthv House. , 60

Our Boor Shelf 61

Letters To Thb Editor :—

The Dutch Photographs of the Eclipse of 1871.—J. A. C. Oudemans 61
Elevation of Mountains and Volcanic Theories.—Rev. O. Fishbh,

F. G.S. Cupt Hutton 6t

Deep-sea Soundings and Deep-sea Thermometers.—Hv. Negretti

and ZAMBkA 6a

Rain-gauge at Sea—W. J. Black Capt. I. E. Goodenough . . . 63

Glaciers.—W. T. Blanfurd, F.G.S. 63

Fohann Nepomuk Czsrmak. Isv Prof. M. Foster, F.R.S 63

The Atmospheric Telegraph {.With Illustrations) 64

The Common Frog, V. By St. Geori;b Mivakt. F.R.S. (H'ttA

1 llusiraiioHS) , 67

Astronomical Almanacs 6a

Man Ik The Settle Cave. By Prof. G. Busk, F.R.S 70

Notes 70

On Some Recent Results With The Towing Net On The Soitu

Coast Op Ireland. By Prof. Allman, F.R.S 73

Scientific Serials • 74

Societies And Academies 7}

« AnteriorContinuar »