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. [602

GEOLOGY.

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 a 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 HNO3. To this, after analysis, the symbol (Fe, Ni3)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 NO3, 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 HCl or by H NO alone, and gave, on analysis, the formula (Fe, Nig) P2. Another crystal was found, which was apparently a square prisin, having brilliant metallic sides, with a dark, almost black centre. Its analysis gave the formula (Fe, Ni2) 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

Canadian

METEOROLOGY.

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. -H. A. H.

[605

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

Reviews. 'Japans landwirtschaftliche und allgemeinwirtschaftliche verhältnisse,' by Georg Liebscher (Jena, 1882), is reviewed by Alf. Kirchhoff in Ausland, 1882, 881-887.

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

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

6

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.

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.) [611

G. L. G.

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 a 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

A pleuronectoid hybrid.-A curious flatfish was sent to Dr. K. E. H. Krause of Rostock, and has been noticed by him as hybrid between the plaice (Platessa vulgaris) and turbot (Rhombus maximus). No figures or descriptions are given to enable the reader to form an opinion for himself. -(Arch. ver. freunde naturg. Meckl., xxxv. 119.) T. G. [623 The bones of Lophius piscatorius. An article with this caption has been published by Robert MorThe bones of the skeleton are described in the sequence followed by Cuvier, but with Owen's nomenclature. The article is deficient in the clearness and precision which could only result from comparison with related forms. (Proc. trans. Nova Scot. inst., 5, 340.) T. G.

row.

[624

Fishes of Wisconsin. - A Catalogue of the coldblooded vertebrates of Wisconsin has been furnished by Dr. P. R. Hoy to the geological survey of the state. The classification of the first edition of Jordan's manual has been adopted, and a hundred and forty-two species are catalogued. The list is little more than a nominal one, and is replete with typographical errors. It is not evident, either, to what extent the identifications of species can be relied upon, although the author acknowledges "great obligations to Prof. David S. Jordan, as well as to the lamented Copeland, for valuable assistance in determining species." Dr. Hoy thinks that "Wisconsin has, perhaps, the best facilities for fish-culture of any state in the Union," as there are not less than 1,800 lakes,' covering some 1,400 square miles,' in the state. (Rep. geol. surv. Wisc., i. 427.) T. G. [625

Mammals.

Development of the lachrymal duct in mammals. Von Baer referred the development of the lachrymal canal to an evagination of the pharyngeal cavity; Burdach, to a fold in the skin starting from the corner of the eye. The first to assert that it arises as a groove between the upper jaw and external nasal process was Erdl, whose view was shortly after, but independently, advanced by Coste, and since has been widely accepted. Its accuracy became questionable when Born showed (Morph. jahrb., ii.) that the canal arises in amphibians, lizards, and chicks, as an ingrowth from the inner surface of the epidermis. The ingrowing band becomes subsequently constricted, surrounded by connective tissue, and hollowed out into a canal. Ewetzky (Arch. für augenheilk., viii.) found later the same mode of development in cattle.

E. Legal now reports his investigations on this theme, carried out principally on pigs, but also on mice and rabbits. The first indication of the lachrymal canal is at the time when the nasal pits communicate with the mouth by the primitive choanae, and the Jacobson's canal is well developed, while externally the so-called lachrymal furrow may be seen (pigs, 4.2 cm., extreme length). The epithelium of the lachrymal furrow is thicker than the rest of the epidermis, because there are one or two layers of cells between the basal cylinder and the superficial flat cells, which elsewhere alone constitute the epidermis. The inner surface of the epidermis of the furrow grows into a ridge, which begins at the opening of Jacobson's organ into the nasal cavity. The ridge grows higher, and finally separates from the skin, forming a rod, the separation becoming com

pleted soonest at the nasal end. The upper end of the rod is connected with the upper lid, but soon forms a stout branch, which grows towards, but does not reach, the lower lid of the eye. The details of the growth of the rod are fully entered into. The canalization begins late, and at the ocular end, and is effected by the separation of the central cells of the rod. (Morph. jahrb., viii. 353.) c. s. M. [626

Morphology of the mammalian germ.—The strange hypothesis is advanced by Repiachoff, that the impregnated ovum of mammals is a distinct individual, which divides into two individuals. One of the descendants only, Van Beneden's "entodermatic' segmentation-sphere, grows up like a spore into the complete sexual individual. (This seems over-fanciful.)-(Zool. anz., vi. 65.) C. S. M. [627

Harder's glands in rodents.— Karnocki has recently made some studies upon the nature of these structures in rabbits, guinea-pigs, and rats. In rabbits and hares, in contradistinction to all other rodents, the gland consists of two portions,—a superior (white) and an inferior (reddish gray) half, having a common duct. The latter opens near the free border of the eyelid, and, passing backward directly to the gland, divides, giving off many branches to each half. Within the gland the branching increases until the terminal vesicle is reached. The latter consists of proportionally long, broad, and repeatedly branched serpentine passages, with lateral expansions. There is no constriction of the gland proper at its juncture with the duct. This structure distinguishes the Harderian glands of rodents from true acinose glands, and brings them close to the pyloric and other similar glands. The contents of the glands consist of a protoplasmic stroma in which, in the red portion, large fat globules, but in the white portion only small globules, float. The globules in the red portion vary with the age and condition of the animal.

In guinea-pigs the gland corresponds to the red portion in rabbits. The duct is very small, and hard to find. The fat globules of the secretion are of more equal size than in the rabbit. The Harderian glands of rats contain a large quantity of a granular, red coloring-matter, which is not altered by alkalies or Idilute acetic acid, but becomes bleached in dilute mineral acids. The red-colored secretion is confined to that portion of the gland outside the lumen, that within being colorless. It contains no large fat globules.

The remainder of the paper is devoted to the histology and embryology of the glands.

The author doubts if the glands of the corner of the eye in other groups of animals, hitherto described as Harderian glands, are in reality such. — (Proc. Cracow acad.; abstr. in Biol. central-blatt, ii. 709.) [628

F. W. T.