It is a time-honoured custom in this as in other learned societies, that the annual Session shall be inaugurated and its last meeting closed by an address from the Chair, and it is my duty now to say a few words to you on the occasion of the opening of our 106th Session.

I would have shrunk from undertaking this duty, but for the reason that our indefatigable Secretary, Professor Tait, has expiscated the fact that I am the only one of the Society's Vice-Presidents who has never given any address from the Chair, and thus the Council of the Society was led to insert in their minutes a request—almost equivalent to a command—that I should say something to you on the present occasion. I comply with this, not from any feeling that I am qualified to do so, but on the principle that those who accept the honours of the Society have no right to do so without attempting, however imperfectly, to discharge the relative duties.

Dr John Murray was good enough to send me numerous specimens of Pseudalius alatus, obtained in the summer of 1888 by Mr Robert Gray, on the coast of Greenland, from Monodon monoceros.

This Nematode has been only once described—by Leuckart, but that at a time when the methods of investigation were still imperfect. My results are thus essentially different from his. Leuckart called the species Strongylus alatus, and noted as its habitat the cranial cavity of Monodon monoceros.

This inquiry was commenced in Shanghai at the end of 1884, soon after Koch had published some of his results, and as he was then almost the only worker in the bacteriological field of whom it could be said that he had not published anything, subsequently upset, attention was directed at once to the“comma bacillus.”

Slightly alkaline peptonised meat jelly on plates was used for purposes of cultivation, this being kept at a temperature of 60° to 70° Fahr. by means of an ice chest in hot weather.

The investigators worked independently, but the majority of the cases of cholera under observation were investigated by both.

The mesenteries of many Anthozoa are usually regarded as being arranged in pairs, the members of a pair being adjacent mesenteries. The common shore Anemones, belonging to the Hexactiniæ, show this arrangement very well. In a typical case, the mouth and stomodæum are elongated, and the pairs of mesenteries are arranged in multiples of six. There are six primary pairs passing from the body-wall to the stomodæum, which are complete; six secondary pairs, which may also reach the stomodæum ; twelve pairs of a third series, which are not complete; forty-eight incomplete pairs of a fourth series, and so on.

The magnificent sections of the Archæan and Palæozoic rocks which are presented on the north-west coast of Scotland, have long been known to all British geologists. They occur principally in the counties of Sutherland and Wester Ross, from Cape Wrath on the north to Loch Kishorn on the south. They are not less striking in an artistic, than they are instructive in a scientific point of view. The height of the mountains, their abrupt and precipitous forms, and the thinness, or almost total absence of, superficial covering, are characteristics which combine with great variety and richness of colouring, to produce scenery which stands altogether by itself

In the preceding part of this paper I considered the consequences of a special assumption as to the nature of the molecular force between two particles, the particles themselves being still treated as hard spheres. My object was to obtain, by means of rigorous calculation, in as simple a form as possible, a general notion of the effects due to the molecular forces. My present object is to apply this general notion to the formation and interpretation of the Virial Equation.

In February 1870, the author made a communication to this Society on the Kombe Arrow-Poison of Africa, a product of the Strophanthus hispidus plant. In that communication the nature of its action on the various structures of the body, and the chemical composition of the seeds of the plant, which are the most active part, were described. It was pointed out that the action is chiefly exerted upon the heart and upon the muscles of the body, and that the seeds contain a crystalline active principle of the nature of a glucoside, to which the name Strophanthin was given

A more or less elaborate system of polymorphism is of frequent occurrence in certain groups of colonial Coelenterata. For example, in many Hydroids certain individuals perform the nutritive functions for the colony, others are specialised for reproductive purposes, and so on. The variously modified individuals are connected together by a general coenenchyma, which enables the nutriment elaborated by the gastrozooids to be utilised by other members of the colony. Perhaps some of the most interesting and complex cases of polymorphism are to be found amongst the Siphonophora

The thermoelectric properties of tin, at temperatures below and above its melting point, were investigated by the writer about a year ago, and the results of the experiments were given in a paper read before this Society. In those experiments, however, the height of the melting point of tin made it impossible, with mercury thermometers, to obtain anything but an approximate indication of the change in the thermoelectric properties in passing the melting point.

Lagrange, in his paper “Solutions analytiques de quelques problèmes sur les pyramides triangulaires,” Nouv. Mém. de l'Acad. Roy. … (de Berlin), Ann. 1773, pp. 149–176, gives unintentionally the following expression of the relationship between the mutual distances of five points in space, viz.

where, if the points be called 1, 2, 3, 4, 5, the letters

and Δ, α, α′, α″, β, β′, β″, are certain functions of the said distances.

A system of five points is completely determined by the vectors joining one of them with the other four. If a, β, γ be three of these, the fourth is necessarily δ = xα + yβ + zγ. Hence any property characteristic of a group of five points will remain when x, y, z are eliminated.

The present paper has a three-fold object:—(1) to give a history of the theories of heredity which have been proposed by so many naturalists, with an appreciation of these in the light of recent advances; (2) to gather together the various contributions which have made the modern restatement possible; (3) to enter a protest against what the author believes to be the extreme position so firmly maintained by Weismann, to whom, however, much of the recent progress has been. due.

The genus Phreoryctes has been known to zoologists since the year 1843, but there is no published account of the reproductive system sufficiently detailed to permit of comparison with other Oligochæta. The gonads (testes and ovaries) and spermathecœ were discovered by Leydig, who did not distinguish between ovaries and testes, owing to the immature condition of the specimens studied. This writer considered that the genital products were evacuated through the nephridia of their segment. The supposition is, however, incorrect, as genital ducts exist. Mr W. W. Smith of Ashburton, New Zealand, forwarded to the author in the spring of 1888 a single specimen of a new species of Phreoryctes, which was described in the Annals and Magazine of Natural History for June 1888 as Phreoryctes Smithii. In that paper the gonads and their ducts were briefly described and figured.

In man, in the rabbit, and some other animals the trachea is built up of a series of cartilaginous rings incomplete behind; the rings being completed in this position by the trachealis muscle.

The mucous membrane forms a smooth cylindrical lining for the whole tube, and is covered by a ciliated epithelium.

In the cat and dog the cartilage rings completely encircle the trachea, and overlap posteriorly, and the trachealis muscle, which is well developed, is placed outside the cartilage, and has a powerful action in varying the diameter of the tube.

When this muscle contracts the overlapping ends of the cartilage ride one upon another, and the projecting ends form a vertical ridge down the inside of the trachea, which can be readily seen on slitting the organ open. This ridge is separated by a deep groove from the other end of the plate.

Although the metabolism during starvation has been investigated in the most elaborate and exhaustive manner in the lower animals by many different observers, as yet few observations have been accomplished in man.

In 1880 Tanner undertook a fast of forty days. We have been able to procure only a few fragmentary observations upon his case (British Medical Journal, vol. ii., 1880). At the commencement of his fast he weighed 71.600 kilos., and at the end of twenty-five days his weight had fallen to 60.000 kilos., indicating a loss of about 11.600 kilos., or .162 kilos, per kilo. of his original weight.

After some years of patient observation and research, I have found, from direct experiment, that at certain times the contractile or pulsating vacuole of the Protozoa performs the function of a true kidney, or, in other words, its secretion is capable of yielding microscopic crystals of uric acid.

Three organisms were used in these experiments, namely:- Amœba, Vorticella, and Paramœcium.

In a previous communication I described the apparatus first used for counting the dust particles in the atmosphere. That apparatus was constructed of such materials as could be easily obtained ready made, and was fitted together in such a way that any one acquainted with laboratory work could easily repeat the experiments. Though that apparatus is satisfactory enough for preliminary work, and gives fairly good results, yet it is evidently not suited for regular everyday use; and, besides that, there are certain defects in it which can be avoided in apparatus specially constructed.

Pure mineral magnesium silicates are amongst the most difficult substances to decompose by naturally occurring agents. Pure water exerts no chemical action on them, neither does water containing carbonic acid gas, even although the latter body be present to the point of saturation. Fresh spring, river, or lake waters containing alkaline carbonates in solution are also, as my experiments prove, totally unable to decompose pure natural silicate of magnesia. Of course, it must be remembered that the amount of alkaline carbonate in natural waters is very small.

At no time does Nature furnish us with any proof of bodies existing in a state of absolute rest. The whole molecular world, organic as well as inorganic, is, as far as we can ascertain, in constant motion. In consequence of this well-established principle, every function of the body may rightly be considered as resulting from a change in the molecular state of the organ manifesting such, and as being the expression of a correlative variation occurring in its representative nerve centre. Through the agency of long continuance the visceral disturbances are now carried on in a somewhat automatic manner, and fail to excite any feeling of their existence, although they may at one time, in the evolution of higher organisation have produced a conscious sensation.