The basic properties of living systems are remarkably consistent and involve energy interactions between intracellular and extracellular environments. These interactions predispose living systems to deposit minerals from many solutions. The evolution of biomineralisation was not a single cellular invention but rather the association and perfection of a few of these fundamental properties of cell biology. The components of biomineralisation systems involve some mechanism for modifying the activity of at least one ion, an interface for initiating and possibly controlling crystal growth, a diffusion limited size and a mechanism for manipulating the growth of the crystal lattice. The evolution of these components of biomineralisation in the context of geological time inevitably concentrates on the Precambrian–Cambrian boundary. Over a time scale of less than 50 × 106 years there was a proliferation of metazoan phyla, the mineralisation in a large number of taxa and the exploitation of a diverse set of processes involving agglutinated sediments, silica, phosphates and carbonates. A large number of theories have been proposed to explain why biomineralisation occurred at this particular time. Such theories should recognise the importance of the incorporation of the citric acid cycle into the cellular metabolism of many organisms and its exploitation in an aerobic environment, the development of multicellularity which enormously increased the opportunities for modifying ion activities in diffusion-limited sites, and the exploitation of browsing and carnivorous feeding habits. These influences had major effects on ecosystems and population structures and put considerable selective pressure on the advantages that could be gained from a skeleton.

Land use and the management of our natural resources such as soils and water offer great opportunities to sequester carbon and mitigate the effects of climate change. Actions on forestry, soil carbon and damaged peatlands each have the potential to reduce Scottish emissions in 2020 by hundreds of thousands of tonnes. Most actions to reduce emissions from land use have beneficial effects on other ecosystem services, so if we can cut emissions we can in many circumstances improve the environment. The cost of reducing emissions through land use change can be low in relation to other means of cutting emissions. The Scottish Land Use Strategy and the Ecosystem Approach it calls for, employing the concept of ecosystem services, offers a way of balancing environmental, social and economic demands on the land. Scotland's land, soils, forests and waters are all likely to be significantly altered by future climate change. Each of these components of the land-based environment offers opportunities for mitigation and adaptation to climate change. The emerging new imperatives for securing food, water and energy at a global level are equally important for Scotland, and interact with the need for environmental security and for dealing with climate change.

At the commencement of the 1924 geological expedition to Iceland, which was conducted by Dr G. W. Tyrrell and the present writer, aided by a grant from the Carnegie Trust, the author took advantage of his earlier arrival in Iceland by devoting his time to a detailed survey of Viðey, a small island which lies 3 miles E.N.E. of Reykjavík. His interest having been aroused by a study of the curious rock specimens which Mackenzie collected from that locality in 1810 (author, 1925), the writer intended at first to make only a rapid examination of the island in order to ascertain their field relations, and, if possible, to determine their mode of formation. A day's field work, however, convinced him that a more protracted survey would be amply repaid, and this was accordingly undertaken; during two days, out of the total of ten which were devoted to this work, the writer enjoyed the invaluable assistance of Dr Tyrrell.

On a recent occasion, looking into a small shallow pool near Lahore, I saw here and there on its bottom a reddish appearance, which a closer examination showed to be due to innumerable worms, implanted by one extremity in the mud, and waving their free ends in the water. These were the Limnodrilus described below. A quantity of the mud taken for further examination yielded, though in very much smaller numbers, three other Oligochætes, viz. Branchiura sowerbyi, Lahoria hortensis, and a species of Dero.

In the W of Ireland the Ordovician rocks of South Mayo and Clew Bay are now juxtaposed but a comparison of the sedimentary histories of these two sequences shows that they accumulated in basins which were probably separated during most of their history. The large amount of terrigenous detritus present in the Arenig to Llanvirn elements of the South Mayo succession is not manifest in that of Clew Bay until the Llandeilo/Caradoc, by which time sedimentation in South Mayo had ceased. A comparison of the South Mayo Ordovician with that of Girvan in Scotland demonstrates that both sequences had a similar provenance. This source contained an ophiolite, granites and some (probably pre-Dalradian) metamorphic rocks. Sediment dispersal directions for the two sequences are opposite in sense, being primarily northward in South Mayo and southward at Girvan. The two stratigraphies indicate that basement subsidence behaviour in South Mayo was virtually the opposite of that at Girvan where initial shallow water sedimentation was rapidly succeeded by deep water environments at the end of the Llanvirn. The two basins may thus have been marginal to a single Ordovician arc complex. One reason for the opposite sense of basin subsidence may lie in the suggested reversal of subduction polarity during the Ordovician. In this scenario the South Mayo basin may be envisaged as lying to the N of a northward-facing arc during the early Ordovician. A new, northward, subduction direction instigated during the Llanvirn, resulted in a fore-arc basin at Girvan complemented by a closing back-arc basin in South Mayo.

The Cestode material obtained by the Scotia Expedition consisted of eight adult and three larvæ or immature forms. Of these, one (Anchistrocephalus microcephalus, Rud.) is not Antarctic, having been obtained from the Sunfish (Orthagoriscus mola), at Station 107, in 39° 12′ S., 53° 44′ W., on January 1, 1903.

Previous studies on the cytology of the wild and less highly developed “diploid” forms of potatoes have been mainly concerned with the number of chromosomes. Rybin (1933) in his cytological investigation on the South American cultivated and wild potatoes has recorded 12 as the haploid number of chromosomes in seven species including S. Rybinii. Ratera (1938) reported the same number of haploid chromosomes in S. Parodii and six other species indigenous to Argentine.

The present study is concerned primarily with the secondary pairing of chromosomes at meiosis in six “diploid” species with a view to determining the basic number in potatoes and to ascertaining the exact “status” of these species.

In recent papers published in the Proceedings and Transactions of the Society the importance of Size as a factor determining the morphology of the vascular system of Pteridophytes has been discussed (2, 3, 29). The purpose of this memoir is to submit data concerning the vascular system of roots, and to determine to what extent Size may have acted as a causal factor in influencing the morphology of these structures. It has been pointed out that the most useful material for these causal studies is to be found where there is only primary vascular tissue, free from complexities such, for example, as the formation of secondary wood. In the case of leafy shoots the vascular system is often profoundly influenced by the insertion of the appendages, especially where the latter are of the megaphyllous type. In many of these instances the resulting vascular structure is due to a complex of so many interacting factors that the specific effect of any one is very difficult to determine. To understand the influence of any one factor in particular we must turn, as Professor Lang has pointed out, to the study of favourable cases (19). These are to be found where the structure is of primary nature, unaffected by the activity of secondary meristems, and where the organ in question is influenced as little as possible by the insertion of appendages.

Our first investigation of Scottish plankton in 1901–2, although only tentative and somewhat meagre, was sufficient to show that, as regards the phytoplankton, the lochs of the west and north-west of Scotland were probably richer than any lakes previously examined. Owing to the extraordinary richness of the few collections then examined, it was considered eminently desirable that the investigation should be further extended. This we have been enabled to do by means of a third successive grant from the Royal Society, and the present paper is one of the results of a visit to the north-west of Scotland in July, August, and September, 1903.

The High Tatra granite intrusion is an example of a Variscan syn-tectonic, tongue-shaped intrusion. In some portions of the intrusion, structures occur which appear to be of sedimentary origin. These include structures similar to graded bedding, cross-bedding, troughs and flame structures, K-feldspar-rich cumulates and magmatic breccias. Formation of these structures might be related to changing magma properties, including crystal fraction, development of a crystal mush and a decrease in magma viscosity, stimulated by influx of mafic magma and high volatile content. The suggested processes in operation are: gravity-controlled separation, magma flow segregation, deposition on the magma-chamber floor, filter pressing and density currents stimulated by tectonic activity.

%The formation of the sedimentary structures was also aided by the presence of large numbers of xenoliths that acted as a heat sink and influenced the thermal field in the intrusion, stimulating rapid cooling and crystal nucleation. Sinking xenoliths deformed the layering and, to some extent, protected the unconsolidated crystal mush from erosion by magma flowing past.

%Areas with well-developed sedimentary magmatic structures can be viewed as having involved magma rich in crystals locally forming closely-packed networks from which residual melt was extracted by filter pressing, and preserved in leucocratic pods and dykes. Interleaved, non-layered granite may be interpreted to have formed from the magma with initially low crystal fractions.

%It is suggested that the intrusion was formed from numerous magma injections representing different stages in the mixing and mingling of felsic and mafic sources. It solidified by gravitation-driven crystal accumulation and flow sorting on the magma chamber floor and on the surfaces of large numbers of xenoliths. Shear stress acting during intrusion might have influenced the formation of magmatic structures.

Trace element inversion modelling of Grenvillean anorthosite massifs and associated rocks yield NMORB-normalised trace element profiles enriched in highly incompatible elements; commonly with negative Nb and Th anomalies. Model melts can be divided into subtypes that cannot be linked through fractional crystallisation processes. Most model melts are depleted in the heavy rare-earth elements and can be explained by partial melting of arc basaltic sources (5–60 melting ) with garnet-bearing residues. Some of the model melts have flat NMORB-normalised profiles (for rare-earth elements), have high compatible element contents, and might have been derived from mantle fertilised by arc magmatism, followed by low-pressure fractional crystallisation. Intermediate Ce/Yb types may represent mixtures of these end-members, or less probably, variations in the crustal source composition and residual assemblage. The active tectonic context now favoured for the Grenville Province appears to be inconsistent with plume or thermal insulation models. The heat source for crustal and mantle melting could record either post-orogenic thermal relaxation of a tectonically-thickened arc crust, or basaltic underplating caused by delamination of a mantle root or subduction slab beneath this arc crust. In this context, pre-Proterozoic anorthosites may be lacking, because prior to ca. 2·5 Ga, the crust may have been too weak to be thickened tectonically. The absence of post-Proterozoic anorthosites may be due to the secular decrease in radiogenic heating and cooling of the mantle and crust.

Campbell Island is a small, uninhabited peat-covered island lying in the cool southern ocean 600 km south of the New Zealand mainland. Dracophyllum scrub is the main cover from sea level to 200 m, above which tussock grassland, macrophyllous forbs and tundra dominate. Seven peat profiles from sea level to the tundra zone provide an elevational transect for pollen and charcoal records spanning the last 500 years. Scrub density was relatively low between 200 and 400 cal yrs BP, possibly due to Little Ice Age cooling, but had recovered by the time Europeans discovered the island in AD 1810. Burning and grazing during a brief farming episode (AD 1895–1931) severely reduced scrub and palatable grasses and forbs. Vegetation recovery is now well advanced following cessation of farming and the later elimination of all feral grazing animals, cats and rats. Climates were cool in the southwest Pacific during the farming period, and since AD 1970 the island has warmed by c. 0·5°C. However, there has been no upwards movement of the scrubline despite vigorous regeneration of scrub at lower altitudes. The island's cloudy, highly oceanic climate appears to offset increasing summer warmth, and scrubline is likely to rise only if clearer and less windy, as well as warmer, summers eventuate.

A revision of the Carboniferous lungfish genus Ctenodus is undertaken. Ctenodus is the longest-surviving genus of lungfish from the Carboniferous, and is the only one to cross the Lower–Upper Carboniferous boundary. Five species span the period, with species correlated to stage. Species are distinguished by differences in tooth plate morphology. Ridge number increases from the Tournaisian to the Moscovian, and the length to width ratio decreases. A new, almost complete articulated individual of C. interruptus allows identification of this species from pterygoid tooth plates and other characteristics. These, and new features of the postcranial skeleton, are described for the first time. Ctenodus retains primitive features of the skull roof, such as a pair of C-bones and retention of a D-bone; its contemporaries Conchopoma, Sagenodus and Straitonia show the derived condition of these features. Ctenodus retains primitive features of the lepidotrichia, which are distally segmented and bifurcated. However, it also shows the derived condition of the tail region in having a combined first and second dorsal fin: whether there was a separate caudal fin remains unknown.

Luminescence methods were used to date a palaeoenvironmental coastal exposure on Stronsay, Orkney. The section consists of glacial sediments that are overlain by intercalated peats and windblown sands, implying varying past environmental conditions. Rapid luminescence characterisation was undertaken using screening methods in combination with quantitative dating of selected samples, providing information on depositional processes and chronology. A temporal discontinuity between the glacial sediments and later peats encompasses the period associated with an important Mesolithic site located inland, and implies erosional episodes. The onset of blanket bog formation on Stronsay dates to 3760±330 yrs BP, consistent with observations elsewhere in Orkney and northern Scotland. Periods of enhanced aeolian activity on Stronsay occurred in the late Bronze Age (2700±265 yrs BP) and at the beginning of the Little Ice Age (650±75 yrs BP). Recent periods of sand deposition in the 19th and 20th centuries (AD 1865±20 and 1960±5) correspond to periods of known historic storminess. These results add to an expanding catalogue of data on sand movements throughout the Holocene in Orkney, and set a framework to interpret the evolution of nearby archaeological and natural landscapes from prehistoric to modern times.

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.

Since the preliminary cytological work of Doncaster (1906) nothing has been recorded on the maturation of the thelytokously (female-producing) parthenogenetic saw-flies (Ten-thredinidæ). Doncaster worked with the four species now known, according to Enslin (1918), as Empria abdominalis F., E. pulverata Ritz., crœsus varus Vill., and Hemichroa crocea Geoffr., and he concluded (1907) that the chromosome number in the oocyte, polar nuclei and egg pronucleus was 8, there being two maturation divisions giving rise to an egg pronucleus and three polar nuclei. As stated in our note to Nature (1937) recent work on the thelytokously parthenogenetic species, Pristiphora pallipes Lep., by our colleague, Mr L. C. Comrie, confirms Doncaster regarding the number of maturation divisions and polar nuclei, but raises strong doubts on Doncaster's interpretations of chromosome number and behaviour. Doncaster did not make it clear whether the diploid number was 8 or 16, or whether auto regulation occurred during or after maturation. It appears probable that the real diploid number is 16, for intensive study of over twenty species of saw-flies, carried on mainly by Dr F. Greenshields in this department (unpublished work), shows that the characteristic diploid number for Tenthredinidæ is 16. Further, judging by Mr Comrie's research on Pristiphora pallipes, in which the diploid number is also found to be 16, it would appear probable that autoregulation in Doncaster's types is brought about by fusion of egg pronucleus and second polar nucleus.

The Island of Iona, celebrated for its ecclesiastical remains and venerated as the centre of St Columba's activities and as the cradle of Christianity in Scotland, is designated by various names. In Gaelic it is known as “Hy” or “I” (the Island), and has been termed also “Innis-nan-Druidneach” (the Island of the Druids), “I-Colm-Kill” (the Island of Colum of the Cell). The term “Iona” (or “Ioua”) was used by Adamnan in his Latin Life of St Columba, and was thought to be derived from the Hebrew “Ionah” (a dove). A more probable derivation is from the Irish “I-thon” (the Island of Waves).

The term ‘monchiquite’ has suffered such conflicting usage that a redefinition is here proposed: monchiquites are alkaline lamprophyres with essential brown amphibole and/or biotite but not necessarily with olivine, possessing a near-isotropic feldspar-free base of glass (hyalomonchiquites), analcime (analcime-monchiquites) or nepheline (nepheline-monchiquites). This effectively reverts to Rosenbusch's original definition, whilst accommodating established practices in the subsequent literature. Notwithstanding certain published interpretations, the type monchiquites from Monchique and Rio de Janeiro are hyalomonchiquites.

The Monchique monchiquites are associated with camptonites and sannaites in a dyke swarm invading the Monchique foyaitic intrusion. Field, petrological, geothermometric and geochemical evidence is presented to suggest that these dykes resulted from two mixing processes: (i) a version of Bowen's classic reaction between mafic crystals and alkaline liquids—here between cumulus divines and foyaitic magma; (ii) hybridisation of hydrous theralitic and nepheline syenite magmas, restricted by liquid immiscibility. The secondary origin of certain dykes is evinced by extreme mineralogical disequilibrium. The monchiquites could represent a more advanced stage of such processes than the camptonites and sannaites.