THE Borough of Maidstone has issued an excellent and well-illustrated guide to the local museum and art-gallery, with a history of Chillington Manor House, in which the natural-history collections are preserved. Special attention is devoted in the museum to the local fauna, both recent and extinct, notices of various groups of which are given by local naturalists and geologists. The illustrations include photographs of the type-specimen of Chelone benstedi, a local Chalk chelonian now in the British Museum, and of part of the cranium of Odontopteryx toliapica from the London Clay of Sheppey, preserved in the Maidstone collection, the only known specimen of that remarkable bird except the type.

THE all-importance of selection to breeders and, in perhaps a somewhat smaller degree, to plant-growers (where hybridisation comes more largely into play), is universally admitted, but difficulties arise in practice when, as is generally the case, it is desired to improve more than a single characteristic of the animal or plant under experiment. As an aid in overcoming these difficulties, Messrs. Pearl and Surface, in the July number of the American Naturalist, suggest the adoption of a system of selection index numbers," "the idea of which is to combine in a single numerical expression the values of a series of important characteristics, all of which a breeder may be desirous of improving simultaneously. The analytical expression of this idea is discussed in the article, with illustrations drawn from maize and poultry raising, and it is thus shown that the index numbers form a valuable adjunct to the score-card in judging stock.

Two notes on the feathers of kalij pheasants (Gennæus) are communicated by Prof. A. Ghigi to vol. xii. of the Rendiconto of the Royal Academy of Sciences of the Institute of Bologna, the first of these relating to a case of mutation in Gennaeus swinhoei, while the second is devoted to the development of the secondary sexual characters in G. argentatus and certain other birds. In the case of Swinhoe's kalij, certain marked variations from the normal type made their appearance in the feathers of a bird born in captivity, and as these cannot be attributed to hybridism, they are regarded as an instance of true mutation. In the second note the variations from the normal type of colouring and pattern produced in the feathers of the silver-pheasant and its hybrids by accelerated and retarded development are described and figured, and their bearing on the production of secondary sexual characters discussed.

FROM among a number of articles on natural history and geological subjects forming the second part of the fourth volume of Aus der Natur, we select for notice one by Prof. O. Jaekel on a new "find" of Devonian vertebrates between Cassel and Marburg, which has already yielded some very interesting remains, and is likely to produce many more in the near future. From this deposit, which is especially rich in armoured " placoderms,' remains of no fewer than sixty different species of fish and fish-like vertebrates have been obtained, mostly in a wonderfully fine state of preservation, five or six of these belonging to forms previously known only by small portions of the armour. The author gives a restoration of the external form of Coccosteus, based on the new material, and differing very widely from the one in Dr. Smith Woodward's Catalogue of Fossil Fishes." As now restored, the creature has four paired fins, a low but long dorsal fin, with a gap above the interval between the paired fins, and a somewhat similar ventral fin, continued along part of the long, whip-like tail, this long,

slender tail being hypothetically added from evidence supplied by Dr. Traquair. In conclusion, Dr. Jaekel remarks that the most noteworthy feature in the new deposit is the occurrence of the remains of a number of forms of placoderms in one spot, whereas in other places only a few such are found in association. It indicates, in the author's opinion, a kind of "explosive development."

WE have often been surprised at the curiously unscientific, but unfortunately very common, use of the term ovum by medical writers to designate a human embryo which has developed very far beyond the unicellular condition to which alone the term ought to be applied. We believe that a certain section of the medical profession is apt to question the importance of preliminary scientific education, but the short time spent by the medical student over his elementary biology would not be wasted even if it did no more than give him some idea of accurate terminology. The immediate occasion for these remarks is afforded by a paper by Maximilian Herzog in a recent number of the American Journal of Anatomy (vol. ix., No. 3), in which the author describes a very young human embryo, closely resembling that known "Peters' ovum. Our information as to the early stages in the development of man is, from the nature of the case, so extremely meagre that any fresh light on the subject will be welcomed by embryologists. The embryo in question is regarded as representing the earliest stage of normal human development hitherto known, perhaps from one to two weeks after fertilisation.

as

THE Bulletin of the Liverpool School of Tropical Medicine, of which the first number has just been issued, contains correspondence relating to malaria and mosquito reduction at Ismailia and Helouan. At Ismailia the expense of the anti-malaria measures has averaged 18,000 francs per annum. In 1903 malaria cost the Suez Canal Company 38,200 francs; in 1908 this item dropped to 16,800 francs.

WE have received the second number of the Eugenics Review (i., No. 2, July), published quarterly by the Eugenics Education Society. The contents include editorial notes and reviews of books, and articles by Sir Francis Galton, Mr. John Russell, Miss A. H. P. Kirby, and others. The review cannot fail to be both interesting and instructive to all those who have the welfare of the race at heart.

NICOLLE and Adil-Bey in 1902 reported that the infective particles of cattle-plague virus would pass through the Chamberland porcelain filter "F," and their results were confirmed by Yersin. E. H. Ruediger states (Philippine Journal of Science, iv., 1909, No. 1, p. 37) that he was not able to verify these results, and in a second series of experiments, using four different filter candles, confirms his previous work, no filter candle having been found to allow the cattle-plague virus to pass through.

IT is a usual custom in pharmacological work to state the dosage of drugs as so much per kilogram of bodyweight of animal or man, the subject of experiment or treatment. Prof. Benjamin Moore points out in the Biochemical Journal (iv., Nos. 5, 6, and 7, July) that this method of stating dosage is inaccurate, the dose of a drug for two individuals of different size, apart from peculiar idiosyncrasies, being proportional, not to their weights, but to their body surfaces, in other words, to the twothirds powers of their weights. Thus an adult of 150 lb. weight cannot be given fifteen times the dose for an infant

of 10 lb., but much more nearly a dose only six times as much. It may be that it is this principle which limits the value of some drugs. Thus atoxyl will cure trypanosome infections in mice and rats, but in cattle, horses, and man it is much less effectual. A rat of 140 grams weight can be safely given 0.02 gram of atoxyl. If the dose were proportionate to the body-weight, a man ought to be able to tolerate 10 grams, but, as a matter of fact, about 1 gram is the maximum safe dose, which is in close correspondence to the two-thirds powers of the ratio of weights (1/500).

THE progress of forestry in the University of Cambridge is briefly summarised in the second annual report of the forestry committce issued recently. It is announced that Mr. H. J. Eiwes has made an offer to provide 1000l. towards the erection of a building to serve as a museum and a laboratory, where special attention would be devoted to the study of home-grown timbers. The reader in forestry, Dr. A. Henry, has taken steps to test the suitability of the western larch, Larix occidentalis, a native of North-west America, for planting as a forest tree in the British Isles and Europe; the canker disease of the common larch is being made the subject of systematic experimental investigation by Mr. E. R. Burdon.

HORTICULTURAL and general botanical articles form one of the leading features of the Country Home. The August number contains a contribution by Mr. G. C. Nuttall on plant aspects and plant names, in which, by means of a few examples and clever illustrations, the author shows the reasonableness of popular floral names; it is suggested that the subject is a suitable one for investigating during a holiday. A practical article on tomato culture is provided by Mr. F. W. G. Blyth, where again the excellent reproductions from photographs are conspicuous, and Mr. W. L. Térasse gives advice on the intensive cultivation of strawberries. The monthly calendar and special instructions for the month's work in garden and greenhouse add to the value of the publication.

OWING to loss of the paper for printing, the early numbers of the Philippine Journal of Science for the current year have been delayed. The first botanical number opens with a contribution, by Dr. E. B. Copeland, on the ferns of the Malay-Asiatic region. Largely in connection with the identification of specimens from the Philippines, Dr. Copeland has acquired a knowledge of the ferns of the Malay Archipelago, which has induced him to present a fern flora of this region. This first part refers to ten families, from the Ophioglossaceæ and Marattiaceæ to the Cyatheaceæ. Keys and short diagnoses are given for each family, genus, and species. The most striking innovation is the reduction of the genera Alsophila and Hemitelia to Cyathea. Cyathea thus becomes a genus of about 400 species, of which one-fourth occur in the region under consideration; Dicksonia and Balantium are retained. Under Marattiaceæ a fifth genus is provided by the author's monotypic genus Macroglossum, and Kaulfussia is lost under the synonym Christensenia.

MR. W. J. BEAN contributes to the current number of the Kew Bulletin (No. 6) a note regarding the effect of the past winter on trees and shrubs in Kew Gardens, with special reference to plants of recent introduction. It is pointed out that alternations between cold and unseasonable warmth were more potent than the actual intensity or duration of cold, and, incidentally, it is noted that plants growing in low, damp situations were killed, while

specimens situated on drier ground survived. A considerable number of recently introduced Chinese plants, including Davidia involucrata and Ailanthus Vilmorinii, came successfully through the ordeal, and the author gives a list of rhododendrons from north India that may be considered hardy. Bamboos suffered greatly, with the exception of Arundinaria nitida and A. fastuosa. Other shrubs that proved hardy are Erica stricta, Cistus laurifolius, Genista virgata, and Vaccinium padifolium.

THE Bulletin of the College of Agriculture, Tokyo Imperial University, Japan, vol. viii., 1909, No. 2, contains a paper by S. Kusano on the cytology of Synchytrium puerariae and S. decipiens, parasitic fungi belonging to the phycomycetes, with bibliography, and illustrated with several excellent plates; a description of a new species of moth belonging to the genus Latirostrum, by T. Miyake; and a revision of Japanese Arctianæ, insects injurious to farm crops and fruit and forest trees, by the same author, with descriptions of some new species.

A SERIES of Bulletins, Nos. 141-4, issued from the Colorado Agricultural College, deal with various phases of market-garden work. No. 142 discusses general problems such as tillage, manuring, &c., in the light of local experience, and lays stress on the conditions which must be fulfilled in Colorado if success is to be attained. Among them is the necessity for "shade" crops, i.e. for crops grown with the view of shading the ground from the sun's heat, or, in winter, of reducing the loss of heat by radiation, and thus of keeping the soil temperature more uniform. Another effect of a "shade " crop in summer is to diminish loss of water by evaporation. The other bulletins deal with special crops-grapes, cabbages, and celery.

SOME of the most important agricultural problems of Cape Colony are associated with water supply, and that this fact is recognised is abundantly proved by the number of articles devoted to it in the Agricultural Journal of the Colony. The Karoo is a dry region, and at the same time possesses a very rich soil; this combination is not unusual, and can be paralleled in the dry belt of British Columbia, of parts of the United States, and elsewhere. Its productiveness is limited by the water supply, and recourse is had to various methods for conserving and increasing the amount found to diminish loss of water by evaporation, and dams of moisture in the soil. Special methods of cultivation are are built to store rain-water, which can then be used for irrigation. Attention is also being directed to the effect of forests on water supply.

THE Bulletin de la Société d'Encouragement pour l'Industrie nationale (vol. iii., No. 3) recently published a long and interesting article by M. Hitier on agriculture in Russia. The various regions are described, and a good account is given of the black soils, the steppes, and other well-marked types of soil. Analyses are quoted showing the presence in black soils of o'5 per cent. of nitrogen, 7 per cent. of organic matter, and distinct quantities of carbonates, along with sufficient potash and phosphates; the area covered by these wonderfully fertile soils is considerably larger than that of France. The natural conditions are eminently favourable for agricultural development, but the economic conditions, especially the collective ownership of land and the power of the Mir, are regarded as great obstacles, and the author does not consider any advance possible until these artificial hindrances are removed.

THE movements of the deeper waters of the Skagerack form the subject of an interesting paper by Dr. O. Pettersson which is published as No. 47 of the Publications

de Circonstance of the Conseil Permanent International pour l'Exploration de la Mer. Dr. Pettersson finds that in the underlying deep waters there is a tidal oscillation which can have daily, monthly and annual periods. These oscillations produce variations in the temperature and salinity of the sea at certain depths, and their investigation becomes of great commercial importance owing to their action in determining the coming and the migration of the herring shoals. The great annual oscillation of the coastal water in the Norwegian sea shows amplitudes of more than 100 m., and the corresponding expansion of the coastal waters of the surface to the westward, in the summer months, was found by Hjort and Nansen to cover an area more than 100 miles broad.

A

THE fourth report on earthquakes in Jamaica, by Mr. Maxwell Hall, contains a catalogue of shocks recorded since the commencement of the weather service in 1880, and some interesting particulars regarding the fracture of cables by the earthquake of January 14, 1907. The cable to Colon was broken four miles south of Bull Bay, and to the south of the break the cable was so deeply buried in mud that it parted in the attempt to raise it. more extensive break took place at twenty miles further south, where the cable had been dragged from west to east, and the fractured ends were fully a mile apart, and further south the cable was again buried in mud and had to be abandoned. Captain Morrell, of the repairing ship Henry Holmes, reports that the two ends of the cable fitted together perfectly, the cable was in perfect condition, there were no signs of erosion, and the wires were broken clean as by a tremendous strain, which he considers to have been produced by a landslide from the direction of the shallow water to the deeper. Mr. Hall points out that the soundings indicate a gradient of 740 fathoms in five miles, or about 1 in 6, on the average, from the California bank, but where the great break occurred the sea-bed is apparently level or nearly so; consequently, he considers, the dragging of the cable for a mile or So to the east, and the parting of the ends to the same extent, could only have been produced by a great chasm opening in the bed of the sea to the east of the great break.

THE first part of the " Bergens Museums Aarbog for the current year records an important discovery at Jaederen of a house of the Middle Iron age. It consisted of a single oblong room, the roof resting on beams set upright, distinct marks of which were found in the clay floor, and the interior being filled with remains of the birch-bark roofing. The fireplace was a paved depression in the centre, but fires had been made also in other parts of the apartment. The antiquities discovered were, on the whole, disappointing, consisting mainly of earthenware pots and grindstones, of which illustrations are given in the report. This discovery is notable, because this is the first house of this type which has been found in Norway; but in Sweden they are well known in Gotland, Oland, and Uppland, and they seem to have been noticed in Finland.

PROF. JUNE DOWNEY contributes an article on muscle reading to the July number of the Psychological Review. By muscle reading is meant that well-known communication between one person, the guide, and another, the subject, by means of involuntary movements of the guide, when his attention is riveted in a given direction. The writer contends that concentration of the guide's attention not only induces free involuntary movements, but also leads to more complex forms of "automatic" activity. For instance, although the guide's attention may be

momentarily distracted, his involuntary movements persist unaltered. Or, again, despite his concentrated attention in a given direction, his movements may have reference to a preceding test instead of to the present one. Unfortunately, the scant experimental data given in the present paper and her defects of experimental method make it difficult to accept with confidence any of the writer's interesting conclusions.

DURING a stay at the Sonnblick Observatory (3106 metres) in July, 1908, Dr. A. Wagner, of the Austrian Meteorological Office, made some interesting observations on cloud elements, the results of which are published in the Sitzungsberichte of the Vienna Academy for December last. The author deals with the water contents, both in the gaseous form, as shown by the hair hygrometer, and in its fluid form in drops or ice-crystals, also with the size of the drops. During thick fog the humidity was generally more than 100 per cent., and only sank below that amount when the sun became visible through the fog. The mean of the measurements of the fluid contents of the clouds was about 2 grams per cubic metre; the greatest value was 4.84 grams, and the smallest o 12 gram. The total of the fluid and gaseous contents varied between 9.98 grams and 4.17 grams per cubic metre; the fluid contents were always less than the gaseous. Visibility was found to be inversely proportional to the fluid contents; its dependence on the size of the drops could not be determined, owing to the few measurements made of the latter. The mean diameter of the drops, determined by the optical method, was 33 μ, but only eighteen such observations were made, on three days.

THE July number of the Journal of the Röntgen Society contains a paper by Dr. G. H. Rodman on the historical collection of sixty-three Röntgen-ray tubes which has been got together by the society, and is now in the possession of the authorities of the Victoria and Albert Museum at South Kensington, and will in a short time be installed in two show-cases in the museum. The paper is well illustrated by photographs of the tubes, and will be of great use to those who are unable to pay a visit to the museum to inspect the tubes themselves.

A VALUABLE report by Dr. H. Happel on the present position of our knowledge of the properties of the monatomic gases is to be found in the Physikalische Zeitschrift for July 15. The author, after giving an account of the theoretical advances made by Sutherland and by Reinganum on the assumption of hard spherical molecules, refers to the older work of Maxwell and Boltzmann, based on the molecules repelling each other according to the inverse fifth power of their distance apart. Не shows that the experimental work done during recent years on the viscosity, heat conduction, and diffusion of the simpler gases does not provide more than general support for any of these theories, and that there is great need of further investigation of these properties over very wide limits of temperature. The theory of the gas-liquid state and the theory of binary mixtures as stated by van der Waals have, in Dr. Happel's opinion, proved valuable weapons in the hands of those who, like Ramsay. Travers, Dewar, and Kamerlingh-Onnes, have beer engaged in investigating the thermal properties of the monatomic gases and of mixtures of them.

Α PAPER on refrigerating installations, with specia! reference to the arrangements necessary when narrow limits of temperature are required, was read by Mr. Robert Baliour at a meeting of the Institute of Marine

Engineers held at the White City on July 24. The author's references to the difficulties of dealing with beef are particularly interesting. Beef is much more difficult to keep in condition during a voyage than mutton. The temperature must never be low enough to produce solidification; such would cause the substance of the meat to burst, and on thawing the meat would have a flabby appearance, which would depreciate its value, although perfectly wholesome as food. The temperature should be maintained as nearly as possible at 29.5° F. The animals must not be excited immediately preceding slaughter, or have any sprained joints which would produce decomposition of the joint oil. The atmospheric conditions must not be thundery or sultry at the time of slaughter, or the air heavily charged with moisture, and scrupulous cleanliness must be observed throughout. Indeed, the ideal conditions for the slaughter-house should be those of the operating theatre of a modern hospital. An article in Engineering for July 30 states that there has not hitherto been much success in the bringing of chilled beef from Australia, but an experiment is now being made with a large consignment, and will be watched with interest.

a

IN the recently issued report of the proceedings of the International Committee of Weights and Measures at its meeting held in March last, the following points are of interest. Investigations made at the bureau of the committee at Sèvres have shown that when water at temperatures between 6° C. and 8° C. is saturated with air, the density of the water is diminished by about three parts in million. Vols. xiv. and XV. of the Travaux et Mémoires of the committee, which are expected to be published shortly, will include the researches of M. Chappuis on, the above subject, and also an account of the experiments conducted by MM. Benoît, Fabry and Perot with respect to the length of the metre in terms of wave-lengths of light. The former volume will also contain three important memoirs on the mass of a cubic decimetre of water. The committee announces the adhesion of Chili and Uruguay to the metric convention, and expresses much satisfaction with the proposal of our Colonial Office to distribute copies of the convention to all the British colonies and dependencies. The report includes

two appendices by M. Guillaume. The first is a supplement to his paper entitled "Récents Progrès du Système métrique," which was presented to the general conference of weights and measures in 1907, and the second gives an account of the present state of the question of standard end-measures of length. It would appear from the latter paper that Airy's method for determining the lengths of end-bars, which had almost fallen into desuetude, has recently been employed at the International Bureau with considerable success.

THE issue of the Chemist and Druggist for July 31 celebrates fittingly the attainment of our contemporary's jubilee. The occasion of the annual summer issue of the magazine has been taken to publish a history of the growth of the periodical from its modest beginning in 1859 to the important technical journal it has since become. The contents of this jubilee issue remind us that the Chemist and Druggist has for many years given prominence to the scientific aspects of pharmacology, and has insisted consistently upon the value of a knowledge of pure science if scientific principles are to be followed successfully in technical processes. The present issue contains, in addition, an exhaustive account of the proceedings at the annual meeting of the British Pharmaceutical Conference, held at Newcastle-on-Tyne towards the end of last month.

A LIST of the lectures arranged for the session 1909-10 in connection with the extension section of the Manchester

In

Microscopical Society has reached us. The purpose of this section is to bring scientific knowledge, in a popular form, before societies unable to pay large fees to professional lecturers. The lectures are given gratuitously by members of the society, and all fees paid for lectures are devoted to the working expenses of the section. addition to lectures, the honorary secretary is willing to arrange practical demonstrations in microscopy, microscopical exhibitions, and the mounting of microscopic objects, in connection with the work of natural history societies in the neighbourhood of Manchester. It is noteworthy that there are about sixty lectures from which to choose. The honorary secretary is Mr. R. Howarth, 90 George Street, Cheetham Hill, Manchester.

OUR ASTRONOMICAL COLUMN. OBSERVATIONS OF SATURN'S RINGS.-It will be remembered that on the occasion of the disappearance of Saturn's rings in 1907, Prof. Barnard, and other observers, found that even when the rings were at minimum visibility there still remained bright condensations on either side of the planet. These, Prof. Barnard suggested, were possibly due to the sunlight sifting through and being reflected from the particles comprising the crape ring.

Observations made during 1908 tend to confirm this hypothesis, for, when seen very obliquely, the crape ring appeared much brighter than when seen at such times that the rings are more open, thus showing that the particles are probably but sparsely disposed, and would permit of such transmission and reflection of sunlight as was suggested. The relative apparent brightnesses of the inner and outer bright rings as seen at different epochs also change, for during 1908, when the foreshortening of the rings was great, the outer ring appeared to be the brighter. Prof. Barnard suggests that if we could look normally at the surface of the rings the outer one would be relatively dark, and the crape ring, perhaps, invisible. Although careful search was made for it, Prof. Barnard was unable to detect any trace of the outer dark ring discovered at Mount Revard, and subsequently observed at Geneva and Greenwich (Monthly Notices [R.A.S.], vol. Ixix., No. 8, p. 621).

THE RELATIVE ATMOSPHERIC EFFICIENCY OF TELESCOPES. Innes directs attention -In a letter to No. 411 of the Observatory Mr. R. T. A. to the subject of the relative efficiency of telescopes of different apertures as compared with the theoretical efficiencies. By tabulating the results obtained by Burnham, with various apertures, he shows that if the efficiency of the 36-inch Lick refractor be taken as 10, that of the 6-inch refractor used by Burnham is, relatively, 2.5, the efficiency per inch of aperture apparently decreasing regularly as the aperture increases.

This phenomenon is attributed by Mr. Innes to atmospheric interference; with a large instrument it is more difficult to find a night with perfect definition, and it is only on such nights that close doubles, at the limit of the observer's vision and the telescope's power, can be observed.

THE MOTION OF THE POLE.-No. 4344 of the Astronomische Nachrichten contains a paper by Mr. H. Kimura discussing the polar motion and the 2 component during the period 1890-0-1908-5. The investigation of the fourteen-months' period shows that it changed rather quickly, being 436 days in 1893, 442 days (maximum) in 1897, and 427 days in 1907. No such abrupt change of amplitude accompanied this change of period.

The new discussion is opposed to the previous theory that the annual period varies quickly while the fourteenmonths' period remains nearly constant, the opposite appearing to be the case; but, as Mr. Kimura points out, the problem is a complicated one, in which many variables are inherent, and will have to wait for further observations and study before any definite conclusions are arrived at. Special attention must be given to the effect of lati

tude, and it may be found that the slow variation of the 2 component, especially in phase, is not unconnected with the sixty, or seventy-five, year period of the annual term which was announced by Dr. Chandler.

REPORTS OF OBSERVATORIES.-Mr. Hough's report of the work done at the Cape Observatory during the year 1908 cannot be summarised effectively in a brief note, but one or two points may be especially recorded. The Victoria telescope was in use on 165 nights to secure 601 stellar spectra for line-of-sight determinations; the solar parallax programme having been completed in May, the spectrograph was dismounted, repaired, and adjusted, and is now employed in the determination of the radial velocities of 365 stars between declination 30° N. and the south pole. The value obtained for the parallax was 8.800" 0.006". The astrographic telescope was employed in taking proper motion and parallax plates of some of Prof. Kapteyn's "selected areas.

In the report of the Paris Observatory for 1908 M. Baillaud outlines the re-organised programme of the observatory work. Among other things, we note that the small equatorial coudé is to be employed, by M. Hamy, for the study of sun-spot spectra.

SOLAR RESEARCH.-In the August number of the Observatory Mr. A. A. Buss discusses, at some length, the possible purport of the results obtained in recent solar research, dealing principally with appearance of the D, line of helium. In concluding, he states that he has, on a number of occasions in recent years, seen immense "dark" hydrogen clouds projected on the dark background of the sun's surroundings; this phenomenon he attributes to the projection of the clouds against the slight luminosity of the sun's hydrogen corona.

on

A BRILLIANT METEOR.-Observing at Marseilles June 26, M. Borrelly saw a splendid meteor, which appeared at 14h. om. 56s. (Marseilles M.T.), and illuminated the whole of the sky for some three seconds. The light was extraordinary, and the meteor travelled from Pegasus to the Dolphin, above e Pegasi, in a N.E. direction (Astronomische Nachrichten, No. 4339).

The mouth and nasal cavities form an intermediate field between the external surface of the body supplied by the superficial afferents, and the remainder of the alimentary canal and the respiratory passages supplied by the deep visceral afferents. In this region the nature of the effective stimuli alters. Whereas mechanical and physical stimuli are specially effective when applied to the external surface, chemical stimuli, both gustatory and olfactory, become specially effective in the intermediate zone both in the direction of yielding sensations and of inducing reflexes. of this intermediate field to that of the deep visceral Prof. Sherrington next passed from the consideration afferents proper. Formerly, gastric and intestinal movements and digestion were believed to be controlled by mechanical and chemical stimuli affecting afferent visceral controlling gastric and intestinal movements and digestion More recently a deeper insight into the mechanism has revealed a number of difficulties which militate against the acceptance of the older views. For example, the intestinal movements, both the simple pendular and the more powerful and less frequent peristaltic movements, take place in an isolated loop of intestine after section of all the nerves passing to the loop. In this case there cannot only be no conscious reaction, but even no true reflex act. Further, the removal of the abdominal sympathetic in the dog does not cause any obvious alteration in digestion or intestinal movements. Under such conditions the regulation of movements and digestion is controlled by the intrinsic nerve mechanism of the alimentary canal, namely, Auerbach's and Meissner's plexuses.

nerves.

ASSOCIATION.

THE chief points of general scientific interest in the proceedings of the British Medical Association at Belfast are to be found in the communications read in the sections of anatomy and physiology, bacteriology and pathology, on July 28-30. The following account is practically limited to a brief summary of Prof. Sherrington's presidential address to the section of anatomy and physiology, entitled "The Deep Afferents-their Distribution and Function."

In contrast with our considerable knowledge of the surface afferents, our knowledge of the deep afferents is relatively slight. The deep afferent system may be subdivided into a visceral and a muscular portion, using the latter term in a somewhat wide sense.

From one point of view the visceral portion may be regarded as superficial with reference to the lining membrane of the alimentary canal and respiratory passages, but practically this fact may be neglected. The consciousness of the body is normally almost entirely confined to the external surface. When we take food, it normally disappears from our ken after its passage through the fauces, and consequently if we were guided only by our own consciousness we might doubt the likelihood of the existence of visceral afferents associated with sensation. Yet numerous examples of dim visceral sensations, especially gastric ones, might be adduced. For example, after drinking hot fluids a characteristic gastric sensation is produced. Under pathological conditions numerous visceral sensations may be obtained. The explanation and localisation of the latter form a fruitful field, in the investigation of which physiologists, anatomists, and clinicians might usefully combine. Further, it has long been recognised that afferent nerves are not necessarily associated with sensation. Numerous examples of this fact will be given in the course of this account.

Prof. Sherrington next passed to a subject of great theoretical and practical interest, namely, visceral pain. This subject has long formed a field of controversy, largely on account of the obvious difficulties in the way of its investigation. The observations which have been made on visceral pain are best dealt with in historical sequence.

Haller, one of the earliest investigators of this subject, distinguished parts which feel from those which do not feel. He included the viscera, tendons, and blood-vessels amongst the non-feeling parts. His results were largely obtained by investigation of the human subject, using interrogation of the patient as the test. He also experi

mented on animals. The methods of stimulation used in the latter cases were extreme in character, and consequently throw no light on the results which might be obtained by the use of more normal and adequate stimuli. Johannes Müller held views diametrically opposed to those of Haller. He maintained that the viscera are sensitive.

Amongst later observers, Head almost takes visceral pain for granted, and, following Ross, develops the idea of "referred pain." Lennander's papers are the most recent on this subject. As the result of experiments on man, he comes to the conclusion that the abdominal and thoracic viscera do not feel. The parietal peritoneum is also insensitive, but the subserous layer of the peritoneum is highly sensitive even under normal conditions. When slightly inflamed the subserous layer becomes hypersensitive.

Meltzer's results are opposed to those of Lennander. From a large series of experiments, chiefly on the dog, but also on man, he comes to the conclusion that stimulation of the liver and intestines elicits reactions that indicate pain. After a short period of exposure to the air, the viscera appear to become hypersensitive, slight stimuli producing well-marked reactions.

On considering the results obtained by these observers, it is difficult to imagine that the powerful vaso-motor re