The author contributes the first of a series of memoirs on the craniology of the natives of the countries comprising the Empire of India. The skulls of the hill tribes were from the Lushai-Chin hill tracts, the Nágá Mountains near Manipur, and Nepaul. The author was indebted for the majority of the specimens to former pupils engaged in the public service in India. A short account of the geographical position and of the external characters of the tribes is given, compiled from the writings more especially of Captain Butler, Colonel Lewin, Colonel Woodthorpe, Surgeon-Colonel Reid, General Sir James Johnstone, and from notes furnished to the author by Surgeon-Captain D. Macbeth Moir, Dr C. L. Williams, Surgeon-Major D. H. Graves, Surgeon-Major Bannerman, and Surgeon-Colonel F. W. Wright.

Eleven adult skulls from the Lushai-Chin hill tracts were examined—nine of which were those of men, two of women. Their characters and measurements were described in detail. Four specimens were dolichocephalic, index below 75; five were between 75 and 77·5, and two from the South Lushai hill tracts were above 80; the mean of the series was 76·l. When the two brachycephalic skulls are excluded the mean index was 74·6, so that the people are in the main dolichocephalic. As regards the relation of length to height the mean of the series was 73·8, and as a rule the breadth exceeded the height. Generally speaking the face was orthognathous and chamæprosopic, the nose was mesorhine, the orbit was megaseme, and the palato-alveolar arch was brachyuranic. The mean cubic capacity of the skulls of nine men was 1353 c.cm., the range being from 1270 to 1480.

The ten skulls to which I would direct attention this evening were collected in the island of New Guinea. The first to come into my possession was given to me in 1895 by one of my pupils, Mr F. N. Johnston, the nine others have been recently purchased from dealers. I am not able to name the tribe or tribes by whom the skulls had been sculptured, neither can I state the precise locality at which they were obtained; but the dealer from whom I bought eight specimens told me that they came from the Purari River district. This river rises in the range of the Albert Victor Mountains, and after a known course of 130 miles, it discharges its waters by several mouths into the head of the great gulf of Papua. It is said to be the largest river in the British territory, next to the Fly River.

In a valuable memoir by Messrs Dorsey and Holmes, on a collection of sixteen decorated skulls from New Guinea, published in 1897, the authors state that although they cannot give the locality from which the specimens came, it is probable that they were collected on the northern shore of the Papuan Gulf, in the British Protectorate. Mantegazza and Regalia have figured a skull from Canoe Island in the Fly River, where the frontal bone was sculptured with four concentric circles. Professor Haddon, in his elaborate memoir on the Decorative Art of New Guinea, says that in the museum at Florence are seven skulls, collected by D'Albertis in the Fly River district, which have designs carved on the frontal bone.

The history of seismological research and discovery may be conveniently divided into three great epochs. 1. We have the recording of earthquakes in the popular significance of the term, with an enquiry into their character, based almost entirely upon the (usually) destructive results of their visitation. 2. We find investigators beginning to appeal to experiment to elucidate some of the effects noticed, with a growing appreciation of the necessity of recording all palpable earthquakes, whether destructive or not. One of the most honoured names in this connection is that of Mallet, whose two volumes on “The Great Neapolitan Earthquake” form a classic in the literature of the subject. Most of the developments of recent times will be found in embryo in the pages of this monumental work. 3. The introduction of instruments for recording earthquakes, and, as a natural consequence, the recognition of pulsations and tremors and the various kinds of earthquake too feeble to be detected by our senses.

At every stage in this history, geological and physical problems of intrinsic difficulty have been encountered; and it is to the discussion of some of the most recent of these that this address is devoted.

From the days of Mallet and Hopkins, numerous reports on earthquakes and seismological phenomena have been prepared and published by the British Association; and the last of these, from the industrious pen of J. Milne, F.R.S., formerly Professor of Mining in the Imperial University of Japan, has a surpassing wealth of detailed facts and of suggested theories.

(1.) Introduction.—In previous papers I have had occasion to discuss at some length the relations between Joule's discovery of the elongations accompanying magnetization in iron and Wiedemainn's discovery of the twist produced in an iron wire under the combined influence of longitudinal and circular magnetizing forces. Following out a suggestion of Maxwell's as to the intimate connection between these two phenomena, I turned my attention to nickel, in the hope of finding the Wiedemann effect in it opposite to what it is in iron in low magnetic fields. The fact that, as Barrett ‡ had shown, nickel contracted in length when longitudinally magnetized, whereas, in low fields, iron elongated wds the ground for this hope, which experiment fully justified.

In a recent paper on the strains produced in iron, steel, nickel, and cobalt tubes in the magnetic field (Trans. Boy. Soc. Edin., vol. xxxix., 1898), I have obtained, on sufficiently reasonable assumptions, values for the strain coefficients at the inner and outer walls of these tubes. Hitherto, work by other experimenters on similar lines had been on ellipsoids, rods, or wires, solid through-out. The theoretical discussion of the Wiedemann Effect (as I have called it) was rendered the more difficult on this account, and also because the current producing the circular magnetization flowed through the magnetized material. In my paper of 1888 referred to above, I make an attempt to get a formula by means of which the Wiedemann effect may be calculated from the Joule effect.

The alteration of the amount of hydrolysis by change of temperature has been directly observed in connection with various salt solutions. In the case of ferric salts, quantitative determinations have been carried out by Wiedemann, employing magnetic methods. He showed that, in the case of the sulphate, the amount of hydrolysis is considerably increased by rise of temperature. A similar effect is observed in the case of gallic sulphate, and here the change is directly evident; a solution of the salt when heated deposits white basic salt, which re-dissolves on cooling. A somewhat analogous case which has recently come under my notice, and which, so far as I am aware, has not been noted previously, is provided by thallic sulphate solution. The thallic salts generally are decomposed more or less easily by water, with formation of a brown precipitate, but dissolve in dilute acids, giving colourless solutions (Crooke, Lamy, Willm, Strecker). An acid solution of thallic sulphate, provided it does not contain too great an excess of sulphuric acid, may be used to illustrate several points connected with the hydrolysis of salts. Dilution with water produces a brown precipitate. A similar precipitate is formed in considerable quantity when the solution is warmed; when the mixture cools, the precipitate slowly re-dissolves, and a clear colourless solution is again obtained. It is therefore evident that the formation of the precipitate is not due simply to a colloidal substance being rendered insoluble, but to a greatly increased hydrolytic action.

In 1865 Lord Kelvin published the results of experiments which first made evident “a very remarkable fatigue of elasticity, according to which a wire which has been kept vibrating for several hours or days through a certain range came to rest much quicker when left to itself than when set in vibration after it has been at rest for several days and then immediately left to itself.” On the strength of Lord Kelvin's statement this elastic fatigue of metals has been regarded as a definitely ascertained fact. But, quite recently (Physical Review, March 1899), Mr Joseph O. Thompson has published a paper “On the period and logarithmic decrement of a continuously vibrating wire,” in which he states that it seems probable that “for constant temperature and constant amplitude the logarithmic decrement is constant.” This conclusion is based upon his observation that the logarithmic decrement, in the case of a copper wire, when the amplitude of vibration varied from about 185° to 175°, had the same value after it had been continuously vibrated through the average arc of 180° for fifty consecutive hours as it had at the commencement of that period. Observations upon other metals seemed to support the conclusion.

Lord Kelvin also stated that fatigue caused an increase of the period of vibration. Mr Thompson finds that “no matter what metal was used, no matter whether the arc of vibration was as small as 20° or as high as 200°, no matter whether the wire was long or short, thick or thin (provided of course the breaking strength of the wire was at least twice the weight of the disc), the result was uniformly the same, namely, that when temperature and amplitude of vibration remained constant, the period of vibration was a constant quantity.”

Introduction.—All craniologists are familiar with the form of craniometer or calliper-compasses at present employed for the purpose of ascertaining the various diameters of the cranial box, and they know that these measurements represent certain facts in connection with the breadth, height, and length of the skull as applicable to a number of accepted fixed points upon the surface of the cranium. In effect these diameters are the direct lengths between two points upon an arched surface, i.e., they are the chords of certain arcs, and by the use of the measuring tape we may ascertain the relative proportions between the arc and the chord which subtends it. When several bones contribute to the formation of the arc we may readily determine the relative proportions between each section of the arc ⟨or the chord of each section⟩ and the chord of the entire arc, but it is a much more difficult matter to segment the chord of the entire arc in terms of perpendiculars prolonged to it from definite points upon the arc. For example, by callipers we obtain the glabello-occipital length or chord of the great longitudinal arc, and by measuring tape we may ascertain the frontal, parietal, and supra-inial sections of this arc, but we do not thereby segment the chord of the arc by perpendiculars prolonged to it from the bregma and the lambda. Again, such important transverse diameters of the skull as the minimum frontal, Stephanic, greatest parieto-squamous, and asterionic, are recorded without reference to their proportions on opposite sides of the mesial plane, while the almost constant visible asymmetry of the skull shows that the mesial plane does not necessarily bisect these diameters.

In March of last year I communicated to the Society a paper giving a detailed account of the procedure adopted in an experimental investigation, which I had undertaken at the request of Lord Kelvin, on the heat of combination of pairs of solid metals in the formation of alloys, along with a statement of some results which had then been obtained.

The pairs of metals chosen were copper-zinc and copper-silver, and, briefly restated, the experiments were conducted as follows:—About half a gramme of alloy, reduced to powder by means of a file, was dissolved in dilute nitric acid, and an equal weight of a mixture of the same two metals in the same proportions was also dissolved under exactly similar conditions The difference between the initial and final temperature in each case is an indication of the heat of solution. If the two results are the same then there is no heat of combination in the formation of the particular alloy tested. But if the heat of solution of the mixture exceeds that of the alloy, then there must be heat of combination in the formation of the alloy equal to that difference. The experimental results, then, afford a means of approximately determining in absolute measure the heat of combination of the metals in the formation of an alloy.

The investigation has been continued since my last communication, and I expect to have it finished and to communicate the results to the Society either towards the close of the present session or at the beginning of the next.

The literature of Duplicity in Birds affords, out of a total of about ninety-five recorded cases of multiple formations of all kinds on a single blastoderm, from the stage of the primitive streak to the fourth day of incubation, only a small proportion of instances of “duplicitas anterior.” Dareste (i.) in his atlas figures three; Gerlach (ii.) adds representations of three others—one case of his own, a second originally described by Ahlfeld, and a third by Reichert; Klaussner (iii.) gives a seventh case; and Bianchi (iv.) describes a monstrous embryo at a later stage (1°5 cm. in length).

Most observers have been content with the partial information derived from the study of the whole object, and only three embryos of this class, which have been studied in serial sections, have been described:—

1st. Erich Hoffman's (v.) with three somites.

2nd. Mitrophanow's (vi.) with six somites.

3rd. Kaestner's (vii.) with seven somites.

§ 1. Consider the induction of an electric current in an endless wire when a magnetic field is generated around it, For simplicity, let the wire be circular and the diameter of its section very small in comparison with that of the ring. The time-integral of the electromotive force in the circuit is 2AM, if A denote the area of the ring and M the component perpendicular to its plane, of the magnetic force coming into existence. This is true whatever be the shape of the ring, provided it is all in one plane. Now, adopting the idea of two electricities, vitreous and resinous, we must imagine an electric current of strength C to consist of currents of vitreous and resinous electricities in opposite directions, each of strength ½C. Hence the time-integrals of the opposite electromotive forces on units of the equal vitreous and resinous electricities are each equal to AM.

§ 2. Substitute now for our metal wire an endless tube of non-conducting matter, vitreously electrified, and filled with an incompressible non-conducting fluid, electrified with an equal quantity, e, of resinous electricity. The fluid and the containing tube will experience equal and opposite tangential forces, of each of which the time-integral of the line-integral round the whole circumference is eAM, if the ring be a circle of radius r; and the effect of the generation of the magnetic field will be to cause the fluid and the ring to rotate in opposite directions with moments of momentum each equal to eAMr, if neither fluid nor ring is acted on by any other force than that of the electromagnetic induction.

It is now well known that after reunion of a divided nerve by means of suture, function may return sooner or later, and that not only does this restoration of function imply simple return of sensation and of the capacity of making voluntary movements, but the re-establishment of complete localisation of sensation and of co-ordination of movements. When it is remembered that the individual nerve fibres are supposed to be paths between well-defined centres and peripheral endings, it is clear that so perfect a restoration of function is in many respects remarkable. Thus, in coapting a divided nerve, it is not likely that this can be effected with so great accuracy, that the corresponding ends of the divided nerve fibres can be brought into apposition. It is more likely that in coapting the nerve, most of the ends of the nerve fibres which are brought into contact are ends which do not correspond; and thus it would be expected that in the reunited nerve new paths for the nervous impulses would be established. And yet, despite this complexity of structure and of function, the reunited nerve seems to be as capable as before the division of subserving its functions.

In suturing divided nerves, care is usually given to secure that the two segments are approximated as nearly as possible in their old relationship. Thus, the perfect recovery of localised and co-ordinated function might be due to a majority of the fibres being thus placed in a position for union as before the division to take place.

In the Report on the Entozoa collected by H.M.S. “Challenger” Dr O. von Linstow described two new tapeworms, which he named Tetrabothrium torulosum and T. auriculatum. The resemblance of the head of T. auriculatum with that of Prosthecocotyle Forsteri described by Monticelli seemed to me to indicate that the Tetrabothrium described by Linstow probably belonged to the genus Prosthecocotyle.

Through the kindness of Sir John Murray, I received from the British Museum the original specimens for inspection, for which I wish to express here my warmest thanks. The following lines give the results of my examination; but before entering upon the description, let me say something on the systematic position of these two animals. As I have already remarked, Prof. Monticelli has rightly erected a new genus named Prosthecocotyle for the tapeworm Tœnia Forsteri, Krefft. To this genus belongs, besides P. Forsteri, other parasites of birds which have been placed in the genera Tœnia, Tetrabothrium, Amphoterocotyle, Bothridiotœnia, Bothriocephalus. According to my researches the following species belong to the genus Prosthecocotyle:—

1. P. Forsteri (Krefft), (syn. Tœnia Forsteri, Krefft), from Delphinus Forsteri (Gray) and Delphinus delphinus, L.

2. P. Monticellii, Fuhrmann (syn. Tœnia erostris, ex parte, Bothridiotœnia erostris, var. minor, Lönnberg), from Fulmarus glacialis, L.

3. P. umbrella, Fuhrmann, from Diomedea sp. (?).

4. P. torulosa (Linstow), (syn. Tetrabothrium torulosum, Linstow), from Diomedea brachyura, Temm.

Sections of the hypocotyl of Ricinus communis are frequently examined as typical of the young stem, in which widely separated vascular bundles are ultimately united by a band of interfascicular cambium, and this by giving rise to secondary tissues connects the xylems and phloems of the primary bundles to form concentric continuous rings.

In the young unthickened hypocotyl of Ricinus there are eight such bundles connected by a continuous starch sheath and one layer of smaller cells immediately inside it. In some sections, however, confusion arises owing to the increase of the number of vascular bundles, and in the case of older hypocotyls these extra bundles are embedded in the cambium ring and have rather the appearance of secondarily formed tissues.

It was in the first instance to clear up the origin of these bundles that, at the suggestion of Professor F. W. Oliver, the following work was begun. Afterwards, as there seemed some advantage in working out in full the arrangement of the vascular system in this plant, which is so frequently used as a dicotyledonous type, it has been followed from the root, through the hypocotyl, to the 1st and 2nd internodes of the epicotyl.

The well-developed primary root of the seedling of Ricinis communis averages about 2 mm. in diameter. About 5 mm. below the junction with the stem it enlarges rapidly to attain the diameter of the hypocotyl, which varies between 4 and 5 mm. It is from this swollen portion of the root that most of the first developed lateral rootlets take their origin.

With a view to ascertain as far as possible the minute changes that occur in the cells of the mucous membrane of the stomach during, and after, activity, I procured from England towards the end of winter a number of newts (Triton cristatus).

When they arrived they were very emaciated, and, indeed, in a starved condition, having no doubt but recently awakened from their winter sleep; they appeared, however, quite healthy, and swam well when placed in water, and took and retained food when given to them in the form of lively worms.

These English newts were fed at the same time with the same weight of worm, and killed at intervals after the meal, one being sacrificed every twenty-four hours, to the end of the tenth day.

Such long intervals were allowed to elapse between each sample taken, because Langley (13) states that during winter in thin and emaciated animals that have been fasting for a considerable time the changes take place very slowly.

These constituted the first set of experiments.

In June of the same year I procured a large number of fine Triton cristatus from the Eft Pond in the Braid Hills near Edinburgh. They were in good condition and very lively.

When worms were given them, they ate them readily, and were hungry again in less than twenty hours. However, to make sure that the stomach was quite empty and in a resting condition, I allowed an interval of one hundred and fourteen hours to elapse after the first feeding, and then, selecting newts of about the same size and weight, fed them a second time, each receiving the same amount of healthy worm.

At the meeting of the Society on the 20th February 1893 I had the honour of reading a paper “On the Early History of some Scottish Mammals and Birds.” Perhaps the title both of that paper and of the present should be “Remarks on the Literature associated with some Early Post-Pliocene Mammals.”

The science of a Species means much more than the naming of its several parts by Latin and Greek derivatives. Even as regards these parts, one would like to know something of extinct forms at the time when they had a place among the living, just as, when dealing with recent forms, we find much to shed light on the structure, probable habits, and surroundings, especially of mammals which became extinct in quaternary time. Questions arise that are worth noting, were it for nothing more than to make it clear that the mere obiter dicta even of able and wide-minded experts may often be misleading. The tendency which prevails to determine species by characteristic bone-marks can never be perfectly satisfactory, because there are many instances in which close structural resemblance is associated with great dissimilarity of habit. It is not so easy as some seem to think to distinguish between several of the long bones of the wolf with the corresponding bones of the collie, or between those of the sheep and of the goat. Then, as to footprints on stiff, tenacious quaternary clays, is there any risk of a label?—“marks of the feet of a small ruminant”—the marks being those of the feet of Sus scrofa (ferus) and not of gentle Ovis aries, L.