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.

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.

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.

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.

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.

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 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.

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 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.

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 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.

Kochiproductus coronus sp. nov., a flanged buxtoniid from upper Viséan limestone of Ayrshire, Scotland, is described and a reconstruction attempted. The possible functions of the flange are discussed. Experiments carried out on a laminar flow table indicate that one effect of this structure would be to check the velocity of incoming feeding currents thus trapping sediment and dense particles on the lower flange but allowing the free inflow of food material.

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.

The more or less flat-lying sedimentary rocks that build up the plateau country of the northern, central, and eastern parts of Spitsbergen range in age from Downtonian to Tertiary. The rocks with which it is proposed to deal in this paper constitute the basement underlying this sedimentary succession in the east central part of Spitsbergen, in the region at the head, and to the east, of Klaas Billen Bay, the north-eastern branch of the Ice Fiord (Map, fig. I). An extension of these basement rocks is to be found in the mountains east of Wijde Bay, and similar rocks are to be found in other parts of Spitsbergen, notably in the western mountain ranges. Formations up to the Tertiary, as well as the Pre-Devonian, are involved in the folding of these western ranges; but the rocks dealt with in this paper may be designated as older than the oldest unfolded rocks in the country.

Calathopteris heterophylla gen. et sp. nov. is described from a single petrified stem found in a loose block at Oxroad Bay, East Lothian. It is approximately 17 cm long and 2 cm diameter, being clothed with the swollen bases of incomplete petioles, many reflexed, and arranged in a dense 2/5 phyllotactic spiral. In most petioles the vascular bundle becomes U-shaped in transverse section with six abaxial mesarch lobes. Other leaf-traces divide in the inner cortex to form three concentric xylem strands which differentiate as they pass outward to form a median triarch bundle flanked by two tetrarch bundles. The stem possesses a medullated stele in which short wide tracheids occur in the medulla. Similarities between the petioles and those of Calathospermum fimbriatum Barnard are pointed out while those with three bundles were probably trichotomous (and ?microsporangiate) like Diplopteridium teilianum Walton.

The typical species of this small section and the first to be described is P. cuneifolia. Within its compass are three other plants which in their time have been given specific diagnoses but are here regarded as coming more properly into the category of subspecies—P. saxifragifolia, P. hakusanensis, and P. heterodonta. P. cuneifolia, thus interpreted, has a distribution extending from N.E. Siberia to Japan, the Aleutian Islands, and the Alaskan coast. The section contains two other species—P. nipponica which is confined to Japan, and P. suffrutescens from the Sierra Nevada of California, thus widely separated geographically.

A two-dimensional (2-D) seasonal model has been developed for simulating the transient response of the climate system to the astronomical forcing. The atmosphere is represented by a zonally averaged quasi-geostrophic model which includes accurate treatment of radiative transfer. The atmospheric model interacts with the other components of the climate system (ocean, sea-ice and land surface covered or not by snow and ice) through vertical fluxes of momentum, heat and humidity. The model explicitly incorporates surface energy balances and has snow and sea-ice mass budgets. The vertical profile of the upper-ocean temperature is computed by an interactive mixed-layer model which takes into account the meridional turbulent diffusion of heat. This model is asynchronously coupled to a model which simulates the dynamics of the Greenland, the northern American and the Eurasian ice sheets. Over the last glacial–interglacial cycle, the coupled model simulates climatic changes which are in general agreement with the low frequency part of deep-sea, ice and sea-level records. However, after 6000 yBP, the remaining ice volume of the Greenland and northern American ice sheets is overestimated in the simulation. The simulated climate is sensitive to the initial size of the Greenland ice sheet, to the ice-albedo positive feedback, to the precipitation-altitude negative feedback over the ice sheets, to the albedo of the aging snow and to the insolation increase, particularly at the southern edge of the ice sheets, which is important for their collapse or surge.

The tetrapod Caerorhachis bairdi, probably from the Pendleian Limestone Coal Group in the Scottish Midland Valley, is rediagnosed and redescribed, and its affinities are discussed. Caerorachis was originally interpreted as a temnospondyl amphibian, based on characters that are now regarded as primitive for tetrapods, or of uncertain polarity. Several features of Caerorhachis (e.g. gastrocentrous vertebrae, curved trunk ribs, reduced dorsal iliac blade, L-shaped tarsal intermedium) are observed in certain primitive amniotes. In particular, Caerorhachis resembles ‘anthracosaurs’, generally considered to be among the most primitive of stem-group amniotes.

The phylogenetic position of Caerorhachis is considered in the light of recently published cladistic analyses of Palaeozoic tetrapods. Most analyses place Caerorhachis at the base of, or within, ‘anthracosaurs’. When multiple, equally parsimonious solutions are found, its ‘anthracosaur’ affinities are shown in at least some trees, and are supported by several informative and, generally, highly consistent characters. Alternative phylogenetic placements (e.g. sister taxon to temnospondyls) are usually less well corroborated.

If the fundamental evolutionary split of most early tetrapods into stem-group lissamphibians (e.g. temnospondyls) and stem-group amniotes (e.g. ‘anthracosaurs’) is accepted, then the revised interpretation of Caerprhachis sheds light on near-ancestral conditions for Amniota.

The Late Caledonian granites of Donegal are all intruded into metasediments of the Dalradian Supergroup of Neoproterozoic age, which were metamorphosed and deformed during the Grampian Phase of the Caledonian orogeny at c. 470-460 m.y. They were intruded in a singular pulse well after the main tectonic event, apparently peaking at 407-402 m.y.; importantly after the strong collision of Laurentia with Baltica on closure of the Iapetus Ocean. The plutons are mainly made up of granodiorite and granite, and are all ‘I’ type, but different to Cordilleran ‘I’ types of the eastern Pacific margin. Major element chemistry indicates they are high-K calc-alkaline rocks with a large range in SiO2 content. However three of the plutons (Fanad, Thorr, Ardara), have very high Ba and Sr contents, even higher than Mainland Scotland counterparts; they are high Ba-Sr plutons. Three plutons (Barnesmore, Rosses, Trawenagh Bay) are evolved and are low-Ba-Sr types, while one (Main Donegal) has atypical, intermediate characteristics. The origin of the magmas is still much debated; here we suggest slab breakoff on Iapetus Ocean closure accounts for the special compositions of these magmas and the other major features of Late Caledonian granitic magmatism, including the singular intrusion peak and the associated appinite-lamprophyre suite.