--

Mexican copper-smelting. A native process of working copper ores is described by W. B. Devereux, as now being practised in the state of Jalisco, Mexico, and as producing very pure copper by using two tons of charcoal to one ton of ore. A basin eighteen inches in diameter, and three inches deep in the centre, is made in the earth, and lined with oakashes. Upon one side of the basin two tuyeres are placed, which are blown by a hand-bellows. A log is placed with one end across the basin at right angles with the tuyeres, and is supported on a roller, so that it can be fed up as fast as it is consumed. The charcoal and calcined ore are placed on the side of the log opposite to the tuyeres, and are renewed as fast as they are burned and melted away. Three hundred pounds of ore are said to be smelted in four hours. The copper and cinder settle into the basin; and, when the latter is full, the charcoal is scraped away. The slag, as it cools on the surface, is lifted off in cakes until the copper is exposed. This is allowed to cool. The cake of copper is then removed, and the operation begins again. The copper is so pure that it can be rolled without cracking. The whole smelting process is performed without the aid of a single tool that cannot be obtained in the chase, in the woods, or in the clay-bank. The calcining of the ore is done in an English calciner, left on the location by a former company. — (Trans. Amer. inst. min. eng. ; Col. meeting, 1882.) R. H. R. [598

The patio process in San Dinas, Mex. - As described by Richard E. Chism, the broken silver ore is ground in an arrastre till there is no more grit. It is then brought to the patio, or large, circular, concave, paved floor. Here it is treated at intervals with mercury, salt, and sulphate of copper, and is stirred and worked by the feet of mules. It is then exposed to the sun for some days. Finally, the amalgam formed is washed and retorted. The cheapness of the plant is its great recommendation. This paper is a carefully written description (giving figures) of the process as it is at present used. (Trans. Amer. inst. min. eng.; Col. meeting, 1882.) R. H. R. [599 Charcoal-making in retorts. In a paper on charcoal as a fuel in metallurgy, John Birkinbine states, that at the Bangor furnace, Mich., there are fourteen kilns of eighty cords capacity, in which sixteen thousand cords of wood are annually carbonized. At the Elk Rapids furnace, Mich., there are twentytwo one-hundred-cord kilns, in which forty thousand cords of wood are each year converted into charcoal. The acetic vapors are exhausted from all these kilns by Peirce's patent method, and converted into acetate of lime and methylic alcohol. The two plants produce daily seventeen thousand pounds of acetate of lime, and two hundred and fifty gallons of alcohol.

That the charcoal is not deteriorated by the collection of the acetic vapors, is proven by the reports of the managers of these plants, and by the remarkable records made by both these furnaces. — (Trans. Amer. inst. min. eng.; Col. meeting, 1882.) [600

AGRICULTURE.

Artificial and natural digestion of proteine. — Stutzer, having devised a method for the separation of the true proteine of fodders from the non-proteid nitrogenous matters, has applied this method to the study of the action of acidified pepsin solution on the proteine of feeding-stuffs. As the general result of his experiments, he finds that the nitrogenous matters of fodders may be divided into two groups, called by him proteine and nucleine; the former of which is entirely digestible, and the latter entirely indigestible. Stutzer's results on certain feedingstuffs agreed quite closely with those that have been obtained in actual digestion experiments with animals, and suggested the possibility of thus artificially determining the digestibility of this important class of nutrients in a very simple manner; but no comparative experiments on identical samples were made.

This deficiency has been supplied by Pfeiffer, who has compared the actual digestibility of meadow-hay and lucerne-hay, by sheep, with the results obtained by Stutzer's method. The results of three experiments are given. In each case the actual digestibility was somewhat less than that indicated by Stutzer's method.

A portion of the nitrogenous matter of the solid excrements, however, consists of billiary products, and other matters not derived directly from the food, and therefore not properly classed with its indigestible matters. When this was taken into account in calculating the actual digestibility, a closer agreement was obtained than is shown by the above figures.

On the other haird, however, the nucleine of the solid excrements, as determined by Stutzer's method, was twenty-five to thirty per cent less than the amount found in the fodder, showing that some of the latter must have been digested. It would seem, then, so far as conclusions can be drawn from three experiments, that Stutzer's proposed method may serve to give an approximation to the digestibility of the proteine of a fodder, and possibly prove a useful addition to the methods of fodder analysis, but that his artificial digestion does not correspond in all respects with natural digestion. (Biedermann's centr.-blatt, 1882, 739.) H. P. A. [601

Digestive fluids of the horse. - Space permits only a summary of the more important results obtained in this valuable investigation by Ellenberger and Hofmeister.

a. The saliva. The mixed saliva contains an energetic diastatic ferment, which acts at once on cooked starch, but more slowly on uncooked. Potato-starch is not saccharified during mastication, but minute quantities of oat or barley starch may be. Both the parotid and the submaxillary saliva have a diastatic action, though it is not so energetic as that of the mixed saliva. The action of the mixed saliva equals 'the product of the actions of its components.' In

the blood of the horse, and also in most other fluids and organs, diastatic ferments are present, but in much less quantity than in the saliva. Slightly acidifying the saliva, or mixing it with small quantities of artificial (acid) gastric juice, does not hinder the diastatic action. Greater concentration of the acid hinders the action, but does not destroy the ferment. The saliva acts slowly upon cane-sugar. The parotid saliva contains traces of a peptonizing ferment. The saliva does not act upon cellulose. It can emulsify the fats, but does not decompose them.

b. The gastric juice, and gastric digestion. The gastric digestion of the horse is of more importance than has been hitherto supposed. It continues from one meal to the next. When oats are fed, the contents of the stomach constitute a comparatively dry, crumbly mass, containing sixty to seventy per cent of water. With hay-feeding, the contents are somewhat moister. The normal reaction of the contents of the stomach is distinctly acid. The proportion of acid seldom rises higher than two-tenths of one per cent. It is least immediately after eating, and increases gradually. The gastric juice of the horse is much less acid than that of the carnivora. At the beginning of digestion, only lactic acid is present. Subsequently, hydrochloric acid appears, and more abundantly with hay-feeding than with oats; but lactic acid is always present. In the contents of the stomach there is always found a diastatic, a lactic, and a rennet ferment, and a ferment which dissolves proteine. Starch is digested to a large extent in the horse's stomach: the action is most rapid during the first one or two hours, though depending somewhat on the quantity and quality of the food. Vegetable proteine is energetically digested, and converted into peptones. The action is slight at first, but augments, reaching its completion in three to eight hours, according to the amount of food present. When large amounts of food are taken into the stomach, much pepsin and acid must be secreted to neutralize the alkaline saliva, and initiate digestion; and, consequently, the time required for digestion is longer. If more food is taken in such a case, that previously eaten is crowded into the intestines in an undigested state. -(Biedermann's centr.-blatt, 1882, 805.) H. P. A.

GEOLOGY.

[602

Atlantis revived. - Professor Hull has published twenty-seven "Paleo-geological and geographical maps of the British Islands and the adjoining parts of the continent of Europe," showing the distribution of the exposed strata of the different geological periods, and their concealed extension. In portraying the latter he has been largely aided by the numerous borings which have been made during the last twenty-five years. Some of the maps show the known and theoretical distribution of land and water during the different geological periods.

In preparing these maps, Prof. Hull has become forcibly impressed with two leading ideas, - first, that the present North Atlantic Ocean must for a long lapse of time have been a continental area, whence was derived, to a large extent, the sediment of which many of the British formations are composed; and, secondly, that the Old Highland districts of the British Isles, once they had sprung into existence as such, ever after endeavored to retain their ascendency. He considers "that the North Atlantic was mainly land during the Laurentian, Cambrian, and lower Silurian periods, and was the source of the sediment of which these great formations are composed. It probably first assumed large proportions as a sea or ocean, when so much of the then sea became land;

namely, at the close of the lower Silurian period. But there are grounds for believing that it was largely in the condition of land-surface in still later times; namely, during the carboniferous, Permian (dyassic), triassic, and Jurassic periods, as evinced by the thickening of the sediment both towards the north-west and south-west of the British Isles. This great continent of Atlantis was the parent of much of the strata which now overspreads the plains of Britain and of the adjoining continental areas. With the cretaceous period, its permanently oceanic form and features set in, and were vastly extended during that and the succeeding period of the nummulitic limestone." A description of each plate is given, which is clear and systematic, containing many references to different authorities used. A discussion of each map would require a memoir as large as the original: suffice it to say, that the work has been prepared with care, and reflects great credit on its author. There are many points in the geology of North America which would appear to be strongly in favor of Mr. Hull's views; such as the Jurassic age of the Rocky-mountain uplift, and the absence in the same region of any Silurian strata, the carboniferous limestone reposing on the Taconic or on older rocks, showing that region to have been land during the formation of the vast Silurian sediments of the Mississippi basin; the absence of more recent formations on the north-eastern coast; the fresh-water nature of the Richmond trias, etc. Prof. Hull has done well in attacking the theory of the permanence of ocean-beds, which, in my opinion, is not borne out by the geological facts; and a perusal of his work should encourage others to enter into this very interesting field of research. —(Trans. roy. Dubl. soc. (2) i. xix.) J. B. M. [603

Meteorites.

The Cranbourne meteoric iron.-Two large blocks of meteoric iron were found in Victoria, Australia, in 1854; one mass weighing several hundredweight, and the other three or four tons. This last was sent to the British museum, and has recently been studied quite thoroughly from the chemicomineralogical point of view by Dr. Walter Flight, of that museum.

When this mass was found, only a small portion projected above the soil, while the remaining portion was embedded in tertiary sandstone overlying basalt. Dr. Flight states that the entire mass consists of metallic minerals, and is destitute of silicates. In the course of the analysis, the nickeliferous iron was found to contain numerous minute, brittle, strongly magnetic, apparently square prisms, which form about one per cent of the mass. These prisms are slowly and with difficulty acted upon by HCl, but are readily dissolved in H N 03. To this, after analysis, the symbol (Fe,Ni)P was given, and it was regarded as corresponding to Gustav Rose's rhabdite.

Certain scales were observed lying on the faces and between the plates of the nickeliferous iron crystals, that were in the form of equilateral triangles, having the thickness of stout writing-paper, pliant, strongly magnetic, and of a pure white color. It was found to contain 70.138 % iron, and 29.744 % nickel, and was regarded as being the same as Gustav Rose's tänite, and Zimmerman's meteorine. Since the composition was first definitely made out by Dr. Flight, he proposes for it the name edmondsonite. It would certainly have been a more gracious thing if he had allowed Rose's name to stand, instead of yielding to the species-making mania, and thereby increasing the confusion in mineralogical nomenclature.

The analysis of a brittle, magnetic powder, which

dissolved easily in H NO, and which was regarded as schreibereite, gave the formula (Fe, Ni), P. A large brass-colored, oblique crystal, showing perfect basal cleavage, dissolved readily in aqua regia, but was only slowly acted upon by II Cl or by H NO 3 alone, and gave, on analysis, the formula (Fe,Ni) P2. Another crystal was found, which was apparently a square prism, having brilliant metallic sides, with a dark, almost black centre. Its analysis gave the formula (Fe, Ni), P. Graphite occurs occasionally in this meteorite, both in nodules and in plates. The nickeliferous iron was also examined for occluded gases; and carbonic acid, carbonic oxide, hydrogen, nitrogen, and marsh gases, amounting in bulk to 3.59 times the volume of the iron, was extracted.

It is to be regretted that more attention is not paid by chemists to the question of the average composition of meteoric masses as a whole, instead of giving their time exclusively to the analysis of the distinct minerals the mass may happen to contain. — (Geol. mag., Feb., 1883.) M. E. w. [604

METEOROLOGY.

Canadian weather-review for February, 1883. This review has been issued very promptly. It consists of a compilation of items of interest relating to storms, temperature, precipitation, etc., for Canada. The mean temperature was much below the normal, especially in the maritime provinces. At Sydney, C. B., the defect was 7.1°. A very important table is presented, showing the total number of hours of sunshine at thirteen stations of the dominion. Since the well-being of crops is dependent, in large measure, on the amount of sunshine, such records, it would seem, would be of great value. The service finds 71.2 per cent of its probabilities fully verified. Full record is given of the special disturbances of the magnetic needles at Toronto. These show very markedly the intimate relation between the aurora and magnetism, as has been known for many years. Auroras were seen on the 1st, 4th, 22d, and 27th.

State weather-services. - The Ohio weatherservice has issued its report for January. This shows an addition of six stations since the November report, there being twenty-five in all at the present time. Thirteen of the stations have barometers. The observations, day by day, are published in full, and will form a more satisfactory basis for more detailed study than can be had from stations at greater intervals.

The Tennessee weather-service has issued its first monthly report for February. This shows that twenty-two stations are now observing the weather, and twenty-eight more are soon to join in the work. It is to be hoped that these stations of observation will not only add to our store of knowledge, but also increase interest in a large mass of people to whom an accurate forecast of the weather is of great consequence. The observation of rainfall, for example, is one of the simplest that can be made, and, all along the watersheds of our rivers, would assist very materially in the discussion of floods, droughts, etc. [606

H. A. H.

GEOGRAPHY.

Reviews. Japans landwirtschaftliche und allgemeinwirtschaftliche verhältnisse,' by Georg Liebscher (Jena, 1882), is reviewed by Alf. Kirchhoff in Ausland, 1882, 81-887.

The geographic observations in Nordenskiöld's 'Umsegelung Asiens und Europas auf der Vega' (Leipzig, 1882) are summarized in Ausland, 1882, 947-954.

'In fernen osten; reisen des grafen Szechenyi in den jahren 1877-1880,' by G. Kreitner (Vienna, 1881), is reviewed by A. H. Keane in Nature, Dec. 21, 1882. Elwes' translation of Capello, and Ivens' narrative, 'From Benguela to the territory of Yacca' (London, 1822), is noticed by E. C. Rye in Proc. roy. geogr. soc., iv. 701. -W. M. D. [607

-

(Africa.) Wissmann's letter from Cairo. — Under date of Jan. 5, Wissmann wrote to the German-African association from Cairo, where he was detained by sickness that began on his homeward voyage up the Red Sea. The following abstract notes his more important statements, but his route is difficult to follow from lack of his names on even the most recent maps. Early in December, 1881, Wissmann left Kingenge, with Pogge and a caravan of two hundred men, and, on passing the Lulua, reached the limit of the west African wooded savannahs, and entered the thickly populated prairies of central Africa. Lake Mukamba was reached in the middle of December, in lat. 5° 45′ S., concerning which further details will be given. Passing the populous district of the Bashilange, the explorers came to the Lubi on Jan. 5, 1882, and entered the country of the Bassonge (sing., Mussonge), a fine, strong, industrious race, living in neat villages, with houses surrounded by gardens, and separated by straight streets shaded by palms and bananas. They work in iron, copper, clay, and wood, and understand weaving and basket-making. Two days' march through forests inhabited by elephants and buffaloes led them to the residence of the king, Katjitch, on the Lubilash (Sankuru), lat. 5° 7′ S., where they rested a week. On starting again, there was some difficulty at first in obtaining permission to go; for the king wished them to stay and help him against an attack from the Bakuba on the north. Leaving the Lubilash on Jan. 29, they crossed a fertile, well-watered region, occupied by warlike Bassonge, by long villages of Benecki (sing., Munecki), and by the timid Kalebue, nearly all of whom are cannibals, and, on March 8, came to the Lomami, lat. 5° 42. From here to Tanganyika were found the Batua (Stanley's Watwa), who seem to be the remaining tribes of the early people of this region. They live in miserable huts, without industry or agriculture, and subsist on wild fruits and by hunting. On April 17, the party arrived at Nyangwe on the Lualaba, lat. 4° 13' S., and were well received and aided by the Arabs of that half-civilized town. There the explorers parted. Pogge turned back on May 5; and, after some delay, Wissmann started eastward with a small party on June 1, having much trouble with his men and the people, on the way, till he reached the great lake. There, at Ruanda, he enjoyed the hospitality of the English missionary, Griffith, and made a four days' excursion to the Lukuga, concerning which he promises interesting information as to the part it plays as Tanganyika's outlet. Crossing to Udjidji, the rest of his way led through less unknown country. His most important détour was to Uhha' (Udjowa?), where King Mirambo received him in the most friendly manner, with roast beef and champagne. On Sept. 5 Wissmann was welcomed to Tabora by the French missionaries there, and shortly afterwards reached the German station in Gonda, where he found Böhm and Reichardt about to start on an extended journey farther inland, Kaiser having already set out. On Nov. 15 he arrived safely on the eastern coast.—(Ausland, 1883, 134; Comptes rendus soc. géogr. Paris, 1883, 90.) W. M. D. [608

Rio Bembe.-D. T. das Neves prefaces an account of his exploration of this river, generally given as the

Limpopo on the maps, with an historical sketch of the native government of the region, of which Muzila, son of Manicussa, is at present the head. After the Zambezi, the Bembe is the largest river of eastern Africa. Its valley is very fertile, suitable for the growth of sugar-cane, cotton, etc., and is well populated. To the northward the country is more healthy for Europeans. Its fine forests of valuable wood contain many elephants, and its saline lagoons are full of hippopotamus; but, "in consequence of the absence of native population, the tsetse-fly is found everywhere through it." In a somewhat exalted peroration, the author concludes with, "We have traversed a vast area of the province of Mocambique, finding it all most salubrious and excellent for occupation by the white race. It possesses all the conditions to make it suitable for the immigration of millions of Europeans, who will find its soil more fertile than that they have left. It is perhaps the most populous region of all tropical Africa; and its millions of natives, placed in contact with civilization, will become consumers of innumerable European wares.' -(Bol. soc. geogr. Lisboa, 1882, 336.) [609

W. M. D.

BOTANY.

Ice-plant (Mesembryanthemum crystallinum). M. Herve Mangon calls attention to the ease with which this plant can be cultivated on a large scale as a source of potash. According to him, the fresh plant contains about half of one per cent of potash.-(Comptes rendus, Jan. 8, 1883.) G. L. G. [610

Loss and gain of nitrogen by arable soil. - M. Dehérain gives a very interesting account of his experiments at the station at Grignon, which may be summarized as follows: the loss of combined nitrogen which a harvested field sustains is not due exclusively to the removal of the crop, but is largely attributable to the oxidation of nitrogenous matter in the soil, and its escape in the form of nitrates in drainage-water. The loss is greatest when the use of fertilizers has been most generous, and it ceases when the fields lie fallow. The reason for the latter is, that then the air penetrates less deeply. The results are quite in accord with those previously reached at Rothamsted. (Comptes rendus, Jan. 15.)

G. L. G.

[611

Solar radiation, and assimilative activity. — Timiriazeff, whose experiments upon the action of chlorophyll are of great importance, has lately published in a short note a few of his more recent results. Quantitatively determined, forty per cent of the amount of solar energy absorbed by a green leaf under the most favorable conditions is converted into chemical work. He calls attention to the usefulness of Langley's bolometer in such investigations. (Comptes rendus, Feb. 5.) G. L. G. [612

The difference between the chemical constitution of living and dead protoplasm has been further studied by Loew; and the results of the investigation, too complicated for a short abstract here, accord in the main with those previously noticed in this journal. — (Pflüger's archiv, Feb. 12.) G. L. G. [613 Fertilization of Yucca.-The deliberate pollination of Yucca-flowers by a tortricid moth (Pronuba), to insure the production of seed for its young to feed upon, is will known through the publications of its discoverer, Prof. Riley. From an abstract of a paper read last summer at the Montreal meeting of the American association, by the same observer, it appears that the act of collecting pollen by Pronuba for

the fertilization of the Yucca "is as deliberate and wonderful as that of pollination. Going to the top of the stamen, she stretches her tentacles to the utmost on the opposite side of the anther, presses the head down upon the pollen, and scrapes it together by a horizontal motion of her maxillae. The head is then raised, and the front-legs are used to shape the grains into a pellet, the tentacles coiling and uncoiling meanwhile. She thus goes from one anther to another until she has a sufficiency." The conclusion of Dr. Engelmann, that the apices of Yucca stigmas are not receptive, is confirmed. "The exceptional self-fertilization in Yucca aloifolia, the only species in which it is recorded, is shown to be due to the fact, that, in the fruit of this species, there is no style, the stigma being sessile, and the nectar abundant, filling and even bulging out of the shallow opening or tube. The flowers are always pendulous; and the pollen falling from anthers can, under favorable circumstances, readily lodge on the nectar."-(Amer. nat., Feb.) W. T. [614

Pollination of the fig.-Some light has been thrown on the much-vexed question of caprification, and the relation of the caprifig or Caprificus to the fig-tree, by the studies of Fritz Müller and Paul Mayer. It appears that the caprifig is the male figplant, as Linné believed, and not a distinct race, as Solms-Laubach has recently maintained. Fig-seeds produce both Caprificus and fig-seedlings. The relations between these two forms of an originally monoecious species, and the gall-fly (Blastophagus), on which it now relies for crossing, are very curious. Three broods of the insects each year are brought to maturity in as many crops of flowers of the caprifig; the first two of which are absolutely infertile, while the last does not average one seed to two figs. On arriving at maturity, the wingless males, after escaping from the fruit in which they have developed, seek out other pistils containing females, which, being impregnated before their release, afterward escape, and penetrate other young figs belonging to the next crop, on either caprifig or fig-tree, to oviposit. Being dusted with the pollen of the strongly protogynous flowers from which they have come, they pollinate the receptive stigmas over which they creep; but the flowers of the caprifig only are accessible to their ovipositors. As a result of fertilization, the fig-tree ripens its fruit rapidly, and its seeds are soon scattered by frugivorous birds; but that of the caprifig never becomes eatable. (Müller, Kosmos, Aug. 5, 1882; Mayer, Mittheil. zool. stat. Neapel, iii.; Abstracts, Biolog. central-blatt, Nov. 15.) [615

--

W. T.

ZOOLOGY.

Coelenterates.

The origin of the spermatozoa in Medusae.— In a short paper on this subject, Merejkowsky calls attention to the interesting fact, that the mature reproduction-follicle of Cassiopea or Rhizostoma bears à close resemblance to the same organ of Pelagia during its very young stages. At a very early stage of development, the immature follicles are almost exactly alike in all three genera; but in Cassiopea they undergo very little change. The mature organ is a simple ovoidal pouch, lined with endoderm-cells, and filled with spermatozoa. According to the brothers Hertwig, Pelagia passes through a similar stage long before maturity is reached; but its development in this genus does not stop here, and it finally becomes a long irregular pouch, the tortuous ramifications of which are interlaced in an inextricable tangle. It is easy to discern that the simple pouches of

Cassiopea open, when mature, into the genital sinus, into which Merejkowsky has seen the ripe spermatozoa escape. He believes that similar openings probably exist in Pelagia; and he thinks the failure of the Hertwig brothers to find them is due to the great complexity of the mature follicle in this genus, rather than to the absence of openings.

The paper also contains a minute illustrated account of the transformation of the endoderm-cells which line the follicle into spermatozoa. (Arch. zool. exp. gén., 1882, 577.) W. K. B. [616 Endodermal nervous system in hydroids. — Dr. Lendenfeld states that he independently discovered in Australian species of Eudendrium and Campanularia the ring of glandular cells which has been recently described by Weissman and Jickeli in Eudendrium. He also finds in all the Campanularidae which he has examined a well-developed nerve-ring of endodermal origin, running around the proboscis, just inside the oral opening. In this region a number of sensory cells are found, with stiff hairs, which project among the cilia of the endoderm-cells. The study of sections shows that these sensory cells are connected with the ganglion-cells; and the processes which are given off from these ganglion-cells anastomose with each other in such a way as to form a complete nerve-ring around the mouth. This ring he regards as the central nervous system of hydroids; and he calls attention to the fact that it not only originates from the endoderm, but is without a homologue in the medusae, since none of the medusae are known to have a nerve-ring in this position. (Zool. anz., Feb. 5.) W. K. B.

Crustaceans.

[617

Color in Idotea. - Carl Matzdorff has published an elaborate and fully illustrated memoir on the color of Idotea tricuspidata (= irrorata), -a variously colored isopod abundant on both sides of the North Atlantic. After describing the various color-varieties, which he arranges in five groups, and the minute structure of the integument, particularly the hypodermal pigment-cells, which he regards as true chromatophores, the author discusses at great length the physiology of the changes of color, and the origin of color-varieties. The changes of color are directly influenced, neither by food, temperature, light, nor saltness of the water, but are sympathetic changes induced by the color of the surrounding objects. Warmth and light, however, accelerate, and cold and darkness retard, the color-changes. As in other animals, changes in color are produced by contraction and dilatation of different sets of chromatophores. The synonymy of the species is discussed, and a long list of works cited is given; but Dr. Matzdorff, while agreeing with Harger, that the American irrorata and the European tricuspidata are the same species, rejects the earlier name because it has been used only by Americans!-(Jena. zeitschr. naturw., xvi. 1.) [618

S. I. S.

The Challenger Amphipoda. — The Rev. T. R. R. Stebbing gives preliminary descriptions of some of the more striking new forms of Amphipoda from the Challenger expedition. Only nine species and one genus are described. Unfortunately, no allusion whatever is made to the region or depth from which any of the specimens come. - (Ann. mag. nat. hist., March, 1883.) S. I. S. [619

VERTEBRATES.

The reaction time of olfactory sensations. The time elapsing between the moment of stimulation and the giving of a signal to indicate the perception

of a sensation by the person experimented upon, has been measured for auditory, tactile, visual, and gustatory sensations. Beaunis has now added to the list by a series of observations made on himself in regard to the reaction time of olfactory sensations. From the table which he gives, it is clear that stimuli, as ammonia and acetic acid, which excite, not merely fibres of the gustatory nerve, but also nerves of common sensation, have a shorter reaction time than stimuli which act only or mainly on the nerve-fibres concerned with the sense of smell proper. Excluding ammonia and acetic acid, the table includes camphor, assafoetida, ammonium sulphide, chloroform, carbon disulphide, valerian, mint, and carbolic acid; and the reaction time increases in the above order from .50 to .67 of a second. It was found impossible to determine accurately the moment of olfactory perception of musk. The numbers show that the olfactory reaction time is longer than tactile, visual, or auditory.

In a foot-note the author states, that, since writing his paper, he has learned that Buccola of Turin had been, about the same time, at work on the same subject, and had reached results in the main concordant with those above stated. (Comptes rendus, xcvi. 387). H. N. M. [620

Fine structure of bone.-G. Broesike has published an extensive memoir on this subject (Archiv mikr. anat., xxi. 695), of which Eberth has published an abstract, here reproduced. The first part of the paper deals with the limiting-sheaths of the osseous canal system. The sheaths may be isolated by the action of acids on completely macerated bones. They are but slightly pliable, and reproduce perfectly the forms of the canals. They may be destroyed by certain reagents quicker than the basal substance of bone, from which they are therefore different, their substance resembling keratine in the author's opinion. The sheaths are wanting in embryonic and all young bone. The author speculates as to their origin: he thinks they must arise either as a precipitate from the lymphatic fluids, or else by decalcification of the basal substance. (Neither of these views appears probable.) The osseous corpuscles form a continuous network by the union of their processes. These cells probably have no membrane, and the nucleus soon degenerates. With increasing age, the cells loose their process, and become jagged and smaller, so that there is a space around them; then follows fatty metamorphosis of the protoplasm, and finally complete fatty degeneration, of which the products may be resorbed. The author advances the (very improbable) hypothesis, that the corpuscles are killed by smothering in carbonic acid, accumulated in parts of the bone remote from the blood-vessels. The basal substance consists of uncalcified gelatine, yielding fibrillae, embedded in a calcified cement. The lamellae are formed by primitive layers of fibrillae, which do not intercross and intertwine, although the sets of parallel fibrillae run in various directions. The author distinguishes between regular and irregular fibrillar tissue. (Fortschr. med., i. 10.) c. s. M.

[621

Nerves of the small blood-vessels.-L. Bremer gives a brief résumé of previous opinions on this subject, and reports his own observations made principally on frogs and lizards. He asserts that his statements also apply to the warm-blooded vertebrates. The fine capillaries are accompanied by usually two naked nerve-fibres, which anastomose with one another, and give off fine branches which form a plexus around the vessel. The threads of the plexus give off fine knot-like thickenings on the side towards the wall of the vessel, and these knots are the ultimate terminations. On the veins and arteries there are