Since the publication in 1840 of a brief but valuable memoir by J. D. Forbes, in which that author drew attention to “the traces of ancient glaciers” in the Cuillin Hills, that district has remained almost unnoticed by glacial geologists for half a century. This neglect is doubtless attributable chiefly to the difficulty of access to the mountains, a consequence of their peculiar configuration, which in turn is closely bound up with the glacial history of the district. The present contribution is the outcome of observations made during the years 1895–1900 in mapping the central part of Skye for the Geological Survey of Scotland. In traversing the mountains day after day throughout several successive seasons, the writer has been struck especially by the impressive evidence which they present of glacial erosion as the dominant factor in their sculpture, and to enforce this is the chief object of the present communication.

§ 1. In a communication read before the Society, 3rd December 1900, Dr Muir discusses the generalisation, for more than two pairs of variables, of the proposition that: If

then

If we interpret (x, y) and (ξ, η) iis points in a plane, it is manifest that the transformation thereby obtained is a Cremona transformation. It has the special property of being reciprocal or involutive in character; i.e., if the point P is transformed into Q, then the repetition of the same transformation on Q transforms Q into P. Symbolically, if the transformation is denoted by T. T(P) = Q, and T(Q) = T2(P) = P; so that T2 = 1, and T = T−1. Moreover, if the locus of P (x, y) is a straight line, the locus of Q (ξ, η) is in general a conic.

The behaviour of metals under stress has long been the subject of investigation, both by mathematicians and physicists, so that the laws of strength are tolerably complete. Owing to the importance of iron and steel in construction, these materials have been subjected to very extensive tests, particularly in simple tension and compression.

Numerous tests of cylindrical iron and steel bars in torsion are also available, the bulk of these being tests to destruction of samples of material used in actual machines and structures designed by engineers. In such tests scientific accuracy is not of much importance, the chief consideration being the obtaining of sufficient data for use in design. The most accurate torsional work upon iron and steel has been the work of physicists, and nearly all their investigations have been conducted upon specimens of very small sectional area; the reasons for this, no doubt, being that such specimens in the form of wires are easily obtainable, and of great uniformity in size and quality, while large test pieces are costly to prepare, and, moreover, cause considerable difficulty in testing, because of the magnitude of the forces involved. Owing to the mode of manufacture, the physical properties of wire often differ to a considerable extent from turned specimens of iron and steel. These differences may be caused by the hardening effect of the drawing, minute cracks in the wires, want of roundness, and the like. It therefore appeared probable that experiments on the lines indicated by physicists would be of some service, and it was with this idea that the investigation was commenced.

In the early part of 1900 I received from J. H. Ponsonby, Esq., a small collection of land molluses from N.W. Borneo, with a request that I would investigate and report upon the same. This collection, the property of the Sarawak Museum, proved, on examination, to contain examples of two new genera (Wiegmannia and Isselentia) of great interest. In the case of the former genus there were only two specimens, each belonging to a different species; and as more material was very desirable, Mr Ponsonby very kindly invited the authorities of the Museum to send over, if possible, a further collection. This, in due course, arrived, but contained duplicates of Isselentia only, the remaining specimens being all new species, excepting one, which proved to be the Damayantia dilecta of Issel, which, I believe, has not previously been found since described in 1874.

Introductory.—Among the toothed whales (Odontoceti) the porpoise is the best-known representative of those members of the genus Delphinus or true dolphins which present a rounded muzzle as distinguished from a snout, and consequently it has already frequently been subjected to anatomical examination of a more or less detailed character. As in the case of all the Cetacea, however, the rapidity with which decomposition affects the various tissues and organs has hitherto proved a barrier to a prolonged and systematic examination of them, while, even under the most favourable conditions, the increasing putridity of the carcase has seriously militated against the recording of accurate observations.

In a Note published in the Annals of Botany for December 1899, I gave some account of the structure of two stems from the Lower Carboniferous of Scotland, provisionally named Araucarioxylon fasciculare, sp. nov., and A. antiquum, Kr. (Witham, sp.).

In the present paper these stems are described fully, with the help of illustrations, and others, presenting similar points of interest, are added. The species dealt with are the following:—

Calamopitys fascicularis (Araucarioxylon fasciculare of the Note).

Calamopitys beinertiana (Araucarioxylon beinertianum, Kr.), (Göpp., sp.).

Pitys antiqua, Witham (Araucarioxylon antiquum, Kr. of the Note).

Pitys Withami (Pinites Withami, Lindl. & Hutt.).

Pitys primœva, Witham.

Dadoxylon Spenceri, sp. nov.

At the base of the wings of Anopheles maculipennis, Meig, is a small quadrilateral area (fig. 2, Plate) which has escaped the notice of the systematist, since the nervures in which he is interested lie almost entirely beyond the area in question, and which has escaped the notice of the morphologist, because it presents to him but a confused outline of meaningless ridges and intervening depressions of no structural importance. If, however, the well-preserved wing of a mosquito, whilst still attached to the thorax, be examined, a very curious apparatus can be made out, lying across the centre of the said quadrilateral area which is bounded posteriorly by the alula. This apparatus lies at about equal distances from the anterior and the posterior edge of the wing, and divides the base of the wings roughly into two halves.

The breeding habits of this asterid have been noted by M. Sars, who has described the external features of the developmental stages. He observed the peculiar habit of ‘brooding.’ In the spring of 1840 he found several of the parents at very low-tide-mark fixed to stones in their brooding position. The species he examined is described as Echinaster sanguinolentus, and is apparently the same species, though he speaks of the ‘blood-red’ embryo, whereas my specimens were a light orange. They conform exactly to the tint of the oral surface of the parent. The time of breeding of Cribrella oculata at St Andrews appears to extend from February to April inclusive, and throughout this period the parents are found fairly plentifully, adhering to the under surface of rocks, nursing the masses of eggs or young under their bodies. This habit of protecting its young is also pursued by an allied species, Asterias mütteri, which is equally abundant in the same locality, but the breeding of which is effected earlier, i.e., in November and December. I hope to proceed with the study of this species in the near future.

The study of lakes has received more attention on the Continent than it has in our own country. The inland waters of France and Switzerland have been most carefully surveyed, and in America accurate soundings of many of the lakes have been made by the Geological Surveys. But until recent years this work has been almost altogether neglected in Britain; the Government had considered it to be outside the function of the Ordnance Survey, and though of importance to geological research, it has not been undertaken by the Geological Survey. The absence of adequate knowledge concerning the forms of the basins occupied by the lakes has been a serious obstacle to the geological inquiry as to the mode of origin of these basins. But recently, in the English Lake District and in Scotland, this obstacle has been removed to a great extent through the work of geographers, who have carried out a very complete bathymetrical survey of many of the lakes of those regions; and the importance of this work has been recognised by geologists. But in North Wales not only had no attempt been made to ascertain the configuration of the lake-beds, but in many cases even the depths of the lakes remained unknown.