Sensory nerves are divided into two classes, those of general sensibility and those of special sense. The nerves of general sensibility are distributed to the skin, muscles, or viscera, and convey influences to the brain which give rise to sensations of touch, heat, &c., or to those vague sensations, not definitely localised, which we include under the name of the muscular sense. The nerves of special sense are endowed with special and individual physiological properties. When a nerve of this order is irritated in any way, either by mechanical, chemical, or electrical stimuli, an influence is conveyed to the brain which gives rise to the same kind of sensation as that produced by the normal stimulus on the terminal organ. For example, pressure on the eyeball, as shown by Newton and Young, electrical stimulation by a continuous current, as demonstrated by Pfaff, Helmholtz Ritter, Purkinje, Du Bois-Reymond, and Schelske, produce many of the phenomena of vision, including not only the perception of light, but the perception of various colours and tints. But while this is the case, it is equally certain that each terminal organ responds to its normal stimulus. Thus the retina, though capable of stimulation by pressure or electricity, is specially fitted by its histological structure for the reception of those minute vibrations of the ether which constitute light. But while the terminal organ is capable of receiving a most delicate action of the normal stimulus, the nerve in connection with it is not so affected. For example, although the retina is affected by light, the optic nerve is not so, as may be proved by Marriotte's well-known experiment, by which it may be demonstrated that when the image of an external object falls on the entrance of the optic nerve, there is no corresponding sensation. The nerve is thus insensible to the normal stimulus of the sense organ, the retina.

The unusually fine stem which forms the subject of this paper was found by Mr T. Kerr, of Edinburgh, in rocks of Calciferous sandstone age exposed in a railway cutting at Dalmeny, Linlithgowshire. Mr James Bennie, of the Geological Survey of Scotland, called the attention of Mr Kidston to the fossil, and the latter very generously placed part of the specimen in the hands of one of us for investigation.

Jan Mayen is so inaccessible and so infrequently visited that very little geological and petrographical work has been done on the island. Some rocks were collected during the Austrian “Pola Expedition” of 1882–3; and these were described by Scharizer as porphyritic olivine basalts, with one example of ægirine-trachyte. Four analyses were given, but their quality is so poor that they are practically useless for scientific discussion. Washington lists only one of these, and that among the analyses of inferior quality. The only modern petrographic work that has been done on Jan Mayen rocks is the description of an olivine-trachyandesite by Dr Holmes accompanied by a first-rate chemical analysis by Dr H. F. Harwood, which forms a valuable addition to the seven new analyses recorded in this paper.

Many continental flood basalt provinces contain rhyolites with ‘A-type’ compositions and many studies have concluded that these higher silica rocks are crustal melts from metapelitic or tonalitic country rock. However, although many of the low-Ti continental flood basalt sequences exhibit a marked a silica gap from ∼55–65 wt. SiO2, many incompatible element ratios, and the calculated eruption temperatures (950–1100°C) are strikingly similar between the rhyolites and associated basalts. Using experimental evidence, derivation of the low-Ti rhyolites from a basaltic parent is shown to be a viable alternative to local crustal melting. Comparison of liquid compositions from experimental melting of both crustal and mantle-derived (basaltic) source materials allows the two to be distinguished on the basis of Al2O3 and FeO content. The basalt experiments are reversible, such that the same melts can be produced by melting or crystallisation. The effect of increased water content in the source is also detectable in the liquid composition. The majority of rhyolites from continental flood basalt provinces fall along the experimental trend for basalt melting/ crystallisation at relatively low water content. The onset of the silica gap in the rhyolites is accompanied by an abrupt decrease in TiO2 and FeO*, marking the start of Fe–Ti oxide crystallisation. Differentiation from 55–65 wt. SiO2 requires ∼30 fractional crystallisation in which magnetite is an important phase, sometimes accompanied by limited crustal contamination. The rapid increase in silica occurs over a small temperature interval and for relatively small changes in the amount of fractional crystallisation, thus intermediate compositions are less likely to be sampled. It is argued that the presence of a silica gap is not diagnostic of a crustal melting origin for either A-type granites or rhyolites in continental flood basalt provinces. The volume of these rhyolites erupted over the Phanerozoic is significant and models for crustal growth should take this substantial contribution from the mantle into account.

Biting midges (Diptera: Ceratopogonidae) are a large family of flies that commononly appear in Lower Cretaceous to Miocene strata, with over 280 fossil species (4.3 % of the family), belonging to 49 genera (26 extant; 23 extinct). Morphological characters used in the identification of fossil genera and species are identical to those used in studies of extant Ceratopogonidae and, as a result, their potential indicative value is reliable. Two relictual extant genera, Leptoconops and Austroconops, reported from Lower Cretaceous Lebanese amber, are at least 125 million years old. Certain ceratopogonid genera are indicative for the Lower Cretaceous, Upper Cretaceous, Eocene or Miocene. A morphological character indicative for the Upper Cretaceous and Cenozoic is macrotrichia on the wing membrane of adults. Indicator species and genera are reviewed for all amber deposits. Eocene Baltic amber contains the best known fauna of biting midges, with 109 named species. Some genera are indicative of aquatic and semiaquatic habitats (predaceous genera, subfamily Ceratopogoninae), forests with rotting trees (Forcipomyia), sandy sea shore habitats (Leptoconops), a cold boreal climate (Ceratopogon) or warm climates (Nannohelea, Austroconops, Leptoconops, Meunierohelea, Metahelea). Females require a protein-rich meal and are well known for feeding on the blood of vertebrates, but many feed on other things, so this information can help with the interpretation of palaeoenvironments. Washingtonhelea taimyrica Szadziewski, 1996, described from Siberian amber, is transferred to the fossil genus Palaeobrachypogon: P.taimyricus (Szadziewski, 1996), comb. nov. For Serromyia alphea, mistakenly redescribed and illustrated from Eocene Bitterfeld amber (= Baltic amber) by Szadziewski (1993), a new name – Serromyiaerrata Szadziewski, nom. nov. – is proposed.

New U/Pb results by cathodoluminescence-controlled single zircon dating of rocks from the High Tatra Mountains (Slovakia) constrain ages for the protolith at 2Ga for the granitoids and 3 Ga for the Koncistá migmatite. Concordant single zircon ages date the intrusion of the migmatite precursor at 3567 Ma and the migmatisation at 332 ± 5 Ma. The intrusion of this precursor corresponds with the major granite intrusion in the Western Tatra Mountains. The geodynamic scenario at this time is described as slab detachment of subducted oceanic crust at the active continental margin of Gondwana. The resulting upwelling of asthenospheric mantle brought enough heat for the anatexis of old metasediments and the production of new H- to S-type granites. High Tatra diorites have an intrusion age of 341 ± 5 Ma, constrained by a concordant single zircon age. This age marks the beginning of the Variscan collision of the two convergent continents Laurasia and Gondwana. The intrusion of granites in the High Tatra was confirmed by concordant data at 314 ± 4 Ma, documenting the final stage of the Variscan continent collision.

The following general description of the capsule, trabeculæ, and sheaths of the splenic vessels is based on the examination of the spleen of the Kitten.

The Tunica serosa consists of a single layer of somewhat thick endothelial cells, which is continuous with the peritoneal lining of the body cavity, and in addition of a thin layer of very finely fibrillated connective tissue that lies immediately subjacent to the endothelial layer.

The Tunica propria differs from a true capsule in that it blends along its whole under surface with the splenic parenchyma, from which it cannot be detached without tearing the splenic substance.

The present communication deals with the Nemertines of Millport and its vicinity, the study of which occupied part of the time I spent at the Millport Biological Station during May and June 1909. The material was not completely worked out during my stay there, and most of the section-cutting was left till after my return to India. I wish to acknowledge here the uniform courtesy and kindness which I received from Mr R. Elmhirst, the Superintendent of the Station, to whom my thanks are due for the readiness with which he placed the resources of the institution at my disposal, and for help in other ways.

Between 1897 and 1903 Ardgour was investigated and surveyed for the Geological Survey by J. S. Grant Wilson. His results were published in the Summaries of Progress of the Geological Survey for 1897, 1898, 1900, and 1903, and were later included in Sheet 53 of the Survey's 1 inch to 1 mile maps and in the Glencoe Memoir. Little additional work had been attempted until 1933 when R. M. Shackelton commenced remapping the area. Shackelton was prevented from completing this work, and the writer supplanted him to continue research on the area from 1934 to 1937 under the direction of Professor C. E. Tilley.

The Ardgour estate comprises a rugged, mountainous tract of Argyllshire north of Loch Linnhe. One large and several smaller masses of epidiorite discovered by Grant Wilson (text-fig. 1) have been intruded into rocks of the Moine Series. Apart from large areas occupied by felspathic granulite and other quartzose types there are also limestones in an amount unusual in the normal Moine Series, some finely banded hornfelses and a zone surrounding the epidiorite masses composed apparently of a felspathised or granitised granulite (indicated by a broken line in text-fig. 1). Pelitic types are important in the western part of the area, and, round Sgurr Dhomhnuill in particular, they have apparently been injected by acid material. This at least is the present view, although the ground has yet to be thoroughly studied. There are a number of lamprophyre and basalt dykes, and some granite, in most places brecciated (with the occasional production of mylonite, e.g. Ben Ba), occurs along the line of the Great Glen Fault. Most of the ground is well exposed, although there may be glacial deposits inland and marine deposits round the coast (not differentiated in text-fig. 1).

New experimental determinations of water solubility in haplogranitic melts (anhydrous compositions in the system Qz-Ab-Or and binary joins) and of the viscosity of hydrous Qz28Ab38Or34 melts (normative proportions) and natural peraluminous leucogranitic melt (Gangotri, High Himalaya) are used to constrain the evolution of viscosity of ascending magmas, depending on their P-T paths.

At constant pressure, in the case of fluid-absent melting conditions, with water as the main volatile dissolved in the melts, the viscosity of melts generated from quartzo-feldspathic protoliths is lower at low temperature than at, high temperature (difference of 1-2 log units between 700 and 900°C). This is due to the higher water contents of the melts at low temperature than at high temperature and to the fact that decreasing temperature does not counterbalance the effect of increasing melt water content. In ascending magmas generated from crustal material the magma viscosity does not change significantly whatever the P-T path followed (i.e. path with cooling and crystallisation; adiabatic path with decompression melting) as long as the crystal fraction is low enough to assume a Newtonian behaviour (30-50% crystals, depending on size and shape). Comparison of the properties of natural and synthetic systems suggests that both water solubility and the viscosity of multicomponent natural felsic melts (with less than 30-35% normative Qz) can be extrapolated from those of the equivalent synthetic feldspar melts.

In plates of Rock-Crystal cut perpendicular to the axis of the prism, an unusual kind of polarisation had been observed in the colours seen along the axis. The phenomena were subsequently analysed by M. Biot, who remarked, that in some specimens of quartz, the succession of tints appeared by turning the doubly refracting prism from right to left, while in other specimens the same succession was developed by turning the prism from left to right; and he concluded from his experiments, that the quartz impressed upon the particles of light a rotatory motion, and that this property belonged to the ultimate particles of silex, and was independent of their mode of aggregation.

The same species of colours was afterwards observed, about the same time, by MM. Biot and Seebeck, in transmitting polarised light through considerable thicknesses of some essential oils, and solutions of sugar and camphor; and this new fact seemed to confirm the supposition that the colours were not dependent upon crystallisation.

Detailed studies have been undertaken on in situ spores of the plant Horneophyton lignieri (Kidston & Lang) Barghoorn & Darrah, 1938 preserved in the Rhynie chert. It is concluded that mature spores are trilete, with proximal radial ribbing, and a distal ornament of coni. These spores are identical to Emphanisporites decoratus Allen, 1965, a widely reported and morphologically distinctive dispersed spore taxon. Emphanisporites decoratus is a common element of dispersed spore assemblages from throughout the stratigraphical sequence of the Rhynie outlier, and it is concluded that the dispersed spore taxon E. decoratus was produced by H. lignieri. The nature (reproductive biology, ecology and distribution) of H. lignieri is interpreted on the basis of evidence from the dispersed spore record from the Rhynie outlier and elsewhere. It is concluded that H. lignieri was a common and widespread plant of the Lower Devonian. It flourished in the unusual hot springs environment of the Rhynie chert because it was preadapted to do so, not because it was a highly specialized and adapted plant. Integrated evidence from the in situ and dispersed spore records permits a detailed consideration of the biology of the plant H. lignieri.

Some months ago it was suggested that I should publish my thesis in its unfinished state. I refrained from doing so at that time, as I was unwilling to allow my work to appear until it was ready for publication. When it became apparent that the war. might continue indefinitely. I decided to publish the thesis in such a form as the exigencies of the case would allow.

The Bin and Clashindarroch Forests lie some 40 miles to the north-west of Aberdeen. Clashindarroch Forest, the larger of the two, stretches from the Rhynie-Cabrach road in the south almost to the Huntly–Glass road in the north. The Bogie valley in the east forms another rough boundary for the hill mass that the forest occupies. On the west the area marches with the county boundary. The Bin Forest consists of two main sections—the Bin itself to the north-west of Huntly, and the Balloch which lies between Keith and Grange, being partly in Banffshire. Both of these areas are more or less isolated hills.

The expression “architecture” as applied to the leaf was introduced by Prantl in his monograph on the Hymenophyllaceæ. It may be adopted as connoting the sum of the facts of construction of leaves; together with those principles or methods deduced from them, upon which we find the leaf to be built up. The varieties of size, form, and complexity of leaves appear infinite; but similarities in the scheme of their construction are obvious. It cannot be assumed that where similarities occur they are necessarily due to immediate community of descent. They may or may not be. Parallel development under similar conditions may be, and probably has been often, the source of such similarity. But even so it may be possible to connect the simpler and the more complex within the several lines of nearer relationship, and a study of several such lines may be expected to disclose certain underlying principles or methods which have ruled in the construction of foliar organs at large. The recognition of these, in their evolutionary aspect, is the proper basis for a scientific knowledge of leaf-architecture.

The exposed Precambrian cratonic crust in South Korea is divided into two massifs – the Gyeonggi massif to the north and the Yeongnam massif to the south. Mesozoic granites intruded into both massifs and are mostly I-types. The Jurassic granites form extensive deep-seated batholiths, the Triassic granites are deep-seated stocks and the Cretaceous granites occur as volcanic-plutonic complexes.

The systematic variation of εNd and SrI in the Korean Mesozoic granites could result from the mixing of two components in different proportions to produce the source of the granites. Although most Mesozoic I-type granites were apparently derived from more juvenile crust, the old evolved crustal components seem to have been incorporated in the magmas in various proportions. Mantle–crust mixing can account for the generation of the source of the Triassic and Cretaceous granites in the Gyeongsang basin. On the other hand, crust–crust mixing can feasibly produce the source of the Triassic and Jurassic granites in the Yeongnam massif, the Jurassic granites in the Gyeonggi massif, and the Cretaceous granites in the Yeongdong–Gwangju basin and the Okcheon belt. However, some Jurassic granites in the Yeongnam massif and Cretaceous granites in the Yeongdong–Gwangju basin can be also explained by the mantle–crust mixing. Combined geochemical and isotopic signatures indicate that a simple binary mixing model is inadequate to explain both the geochemical and isotopic data. The chemistry of the granites is considered likely to reflect the composition of the igneous protolith that derived from depleted mantle, which explains why most Mesozoic granites in South Korea are represented by I-types, regardless of their temporal and spatial position. Nd-Sr isotopic signatures of the Mesozoic granites and basement rocks indicate that the continental crust beneath the Korean peninsular is vertically structured by the successive underplating of mantle-derived materials. It is postulated that the crust is vertically stratified from the surface to the lowermost crust with late Archean to early Proterozoic, early to middle Proterozoic (ca. 1·9 Ga), middle Proterozoic (ca. 1·5 Ga), and late Proterozioc (younger than 1·5 Ga) components.

The Permo-Carboniferous eurynotiforms show conspicuous modifications to postcranial and cranial morphology relative to primitive actinopterygian conditions, and represent an important early example of functional experimentation within ray-finned fishes. Although eurynotiforms are represented by abundant articulated fossil material, the internal anatomy of the group is not well known. Microcomputed tomography (μCT) of Eurynotus crenatus from the early Carboniferous (Viséan) Wardie Shales Member of the Gullane Formation of Wardie, Scotland provides detailed information on the jaws, palate and dentition. The lower jaw is deep and bears a well-developed convex dental plate on the prearticular/coronoids. The dentary bears a dorsally directed posterior process and lacks any obvious marginal dentition. The prearticular bears a low coronoid process. Apart from the first and second dermopalatines, and a likely accessory vomer, bones of the palate are tightly sutured or fused. The upper dental plate comprises a longitudinal, concave horizontal dental surface that occludes with the convex lower toothplate, and a more vertical region consisting of anastomosing ridges. The parasphenoid has a narrow anterior corpus and a broad posterior stalk that bears a pronounced midline notch. The smooth, irregularly punctated surfaces of the dental plates are formed by closely packed teeth with conjoined crowns, providing clues to the evolution of the more monolithic toothplates of Amphicentrum from the peg-like teeth reported in the earliest and most anatomically generalised eurynotiforms. The feeding apparatus shows many qualitative and quantitative features consistent with the processing of hard prey items. Eurynotus and its relatives show the first clear example of jaw and dental structures consistent with durophagy among actinopterygians. The origin of the group in the early Carboniferous is suggestive of diversification into newly available ecological roles in the aftermath of the end-Devonian extinction.

It is my intention to undertake a series of Memoirs on that branch of Hydrodynamics which treats of the transmission of reciprocating motion. It may appear superfluous at first, that any further investigation should be bestowed on the general problem, when it is remembered that two of the most able mathematicians of the present age, M. Poisson and M. Cauchy, have devoted so much of their talents and attention to the subject. Yet, when advances are rapidly making in our experimental knowledge, we generally find that the complex and apparently general results, deduced by those who have paid the greatest attention to the science as it presented itself to their view, are in reality only particular cases, when they have to be applied to experiments in their actual form. This circumstance detracts greatly from the value of almost all general investigations; and in this instance it does so in a remarkable degree. The prosecution of the research has been extended in one direction—the prosecution of experimental knowledge has taken another; and thus, in order to meet the challenge of experimenters to keep pace with them, it behoves the theorist frequently to return on his path, and cross over to the line of their march.

Results emerging from the long-term forestry versus upland grassland paired catchment study conducted by the Institute of Hydrology at Plynlimon, mid-Wales, and from studies of the processes controlling the hydrological responses of areas under forest and grassland, have been accepted by the water and forestry industries as a means of determining the probable effects of afforestation in other areas of Britain. When considering proposals in the late 1970s for a further major expansion of forestry, mainly in Highland Scotland, it became apparent that insufficient information was available to predict with confidence the effects in areas where forestry would replace medium height vegetation (heather sp., bracken) or in areas where a significant proportion of the precipitation falls as snow. Against this background a consortium of interested parties (see Hall 1987), agreed in 1981 to fund parallel systems and process studies of the effects in appropriate areas of Scotland. In this paper the initial stages of the systems study, on two catchments in the Balquhidder area of Central Region, are described. Some preliminary results from phase I, in which the catchment water balances under a mature forest and a mixed heather, bracken, grass cover were obtained, are presented. These water balances suggest that water use by the partly forested catchment is lower than that by the control and also lower than Penman ET. These findings are discussed in relation to the Plynlimon results and to information gained in the current process studies. Plans for phase II of the study, in which the mature forest will be clear-felled and part of the heather, bracken, grass control will be planted, are outlined.

The Kilmaluag Formation on the Isle of Skye, Scotland, provides one of the richest Mesozoic vertebrate fossil assemblages in the UK, and is among the richest globally for Middle Jurassic tetrapods. Since its discovery in 1971, this assemblage has predominantly yielded small-bodied tetrapods, including salamanders, choristoderes, lepidosaurs, turtles, crocodylomorphs, pterosaurs, dinosaurs, non-mammalian cynodonts and mammals, alongside abundant fish and invertebrates. It is protected as a Site of Special Scientific Interest and by Nature Conservancy Order. Unlike contemporaneous localities from England, this assemblage yields associated partial skeletons, providing unprecedented new data. We present a comprehensive updated overview of the Kilmaluag Formation, including its geology and the fossil collections made to date, with evidence of several species occurrences presented here for the first time. We place the vertebrate faunal assemblage in an international context through comparisons with relevant contemporaneous localities from the UK, Europe, Africa, Asia and the US. This wealth of material reveals the Kilmaluag Formation as a vertebrate fossil assemblage of global significance, both in terms of understanding Middle Jurassic faunal composition and the completeness of specimens, with implications for the early evolutionary histories of mammals, squamates and amphibians.