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.

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.

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.

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.

The publication by Kidston and Gwynne-Vaughan ïn 1912 of a memoir on Stenomyelon tuedianum Kidston marked the beginning of a proposed series, which was never continued by them, on the Carboniferous Flora of Berwickshire, based upon material collected during 1900 and 1901 from rocks of the Calciferous Sandstone Series (Cementstone Group) at various localities in Berwickshire while Kidston was working with Mr A. Macconochie of the Geological Survey. Brief notes on this material, with identifications of some of the plants found in compression form, were contributed by Kidston to the “Summary of the Progress of the Geological Survey” (Kidston, 1901, 1902 a), where he commented upon the interest and importance of the material; but beyond recording the occurrence of petrified specimens, no further description of these was given at the time. An incomplete list of anatomical species identified from this Berwickshire material was also given by Kidston at a later date (Kidston, 1923, p. 19). Some of the petrifactions, in addition to the Stenomyelon tuedianum already referred to (Kidston and Gwynne-Vaughan, loc. cit.), have been described by various writers, mostly from specimens in the Kidston Collection of Fossil Plant Slides in the Botany Department of Glasgow University, where the majority of the sections is to be found.

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).

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.

Two trilobite faunas of late Ordovician (Sandbian and Katian) age are described from the siliciclastic Karagach Formation, western Tarbagatai Range, eastern Kazakhstan. They comprise 15 families and 24 genera and include the new taxa Agerina acutilimbata sp. nov., Birmanites akchiensis sp. nov., Dulanaspis karagachensis sp. nov. and Kimakaspis kovalevskyi gen. et sp. nov. Most of the Karagach Formation yields graptolites characteristic of the Diplograptus foliaceus [multidens] Biozone, which are associated with the older trilobite fauna; the uppermost part, which is the source of the younger trilobite fauna, contains Orthograptus quadrimucronatus and Dicranograptus hians which suggest a younger age, equating with the lowermost Ensigraptus caudatus Biozone, and the base of the Katian Stage. Most of the trilobite genera in both faunas have a wide geographical distribution in the late Ordovician, although Dulanaspis and Sinocybele are characteristic of low latitude eastern peri-Gondwanan faunas.

When Pax (1) in 1889 constituted his section Sinenses, he was well aware that it contained at least three distinct groups, each of which could with good reason be regarded as separate sections. Of these the one which he designated Poculiformia is the equivalent of Obconica. This group Poculiformia (while sharing in the general definition of Sinenses) he marked off by the beaker-shaped calyx which is generally accrescent after anthesis. In his view the group comes nearer to group Cortusina (i.e. section Cortusoides) than to the more isolated Auganthus (i.e. Sinenses sensu restricto), which may quite well be the case. In its turn the group Cortusina is to be distinguished from Poculiformia by the character of its calyx—a tubular or cylindrical structure. Of the species quoted by Pax as within Poculiformia, only four are now considered legitimate members of Obconica—P. obconica, P. filipes, P. Listen, and P. oreodoxa.

Coprolites of four distinct shapes, cylindrical, discoidal, beaded and irregular masses, are described from 11 horizons within Bed 16 of the Foulden sequence. These coprolites are composed of either phosphatic or claystone material, although they have not been analysed mineralogically or chemically. Their producers appear to have been fish, probably both nektonic predators and nekto-benthonic scavengers or detritus feeders.

Ostracods are poorly preserved and of two broad types, thick shelled paraparchitids including Shemonaella scotoburdigalensis and thin shelled podocopids, possibly species of Carbonita or Cavellina. This ostracod assemblage represents a conservative ‘carbonaceous fades’ fauna which occurs widely in plant-rich sediments in lower Carboniferous (Courceyan) sequences of northern England and southern Scotland. Other microfauna includes spirorbid worm tubes, fish scales, arthropod cuticle fragments, spat of myalinid bivalves, plant fragments and spores. No significant changes in the vertical distribution of the microfauna could be detected.

The microfauna indicates a general fresh to brackish water lacustrine or lagoonal environment possibly with access to quasi-marine conditions.

The district examined in the course of the research embodied in this paper is the south-eastern part of the county of Fife, lying between the coast-towns of Aberdour and Kirkcaldy, and stretching inland to a roughly semicircular boundary enclosing Auchtertool, Raith and Chapel. The area within these limits, amounting to approximately 30 square miles, was mapped on a scale of 6 inches to a mile, and the chief results of the field-work are shown in the map on Plate III.

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.

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.

A comprehensive study of the ∼2200-Ma-old Kuetsjärvi Sedimentary Formation (KSF), NW Russia, was undertaken to contribute to our understanding of palaeoenvironments associated with the global perturbation of the carbon cycle between 2330 and 2060 Ma. Closely spaced drill core samples (n=95) were obtained from a 150-m-thick unit deposited in rift-bound fluvial-deltaic and shallow-water lacustrine settings with a short-term invasion of sea water. Apart from a very few de-dolomitised samples, all other carbonate lithologies are represented by Corg-free, S-poor, quartz-rich dolostones, stromatolites and travertines which have high Sr concentrations (51–1069 ppm) and low Mn/Sr ratios (2·9 ± 2·1). The carbonate succession, excluding travertines, shows high δ13C (+7·5 ± 0·6‰, n=95) with a limited variation (+5·8 to +8·9‰). Fluctuating δ18O values (10·8–20·4‰) were overprinted during diagenesis, regional greenschist-grade and later retrograde metamorphism. Several short-term stratigraphic excursions of δ13C were apparently governed by evaporation and CO2 degassing combined with pulses of12C-rich hydrothermal waters precipitating travertines. However, the 13C-rich nature of the dolostones reflects the global isotopic signal, which was modified in a shallow water lacustrine environment by evaporation, enhanced uptake of 12C by cyanobacteria, and pene-contemporaneous oxidation and loss of organic material. The best proxies to δ13C and 87Sr/86 Sr of coeval sea water recorded in the KSF dolostones are likely to be around +5–6‰ and 0·70406, respectively. The study of the KSF has shown that circumspection is necessary when attempting to model the behaviour and evolution of the global C-cycle in Deep Time. Models which purport to explain global oceanic–atmospheric evolution without first adequately accounting for the possibility that many Precambrian carbonate deposits might be non-marine, or at least influenced by non-marine fluids, should be viewed with caution

Notoungulates, native South American fossil mammals, have been recently objective of several palaeoecological studies. Ecomorphology and biomechanics of the masticatory apparatus, together with micro and mesowear analyses on tooth enamel, were applied in order to understand their palaeobiology. In particular, the relationship between some dental traits (hypsodonty, occlusal surface area and complexity) and body mass is still poorly understood. These features were measured by means of the hypsodonty index (HI), occlusal surface area (OSA) and tooth area (OTA), enamel crest complexity (ECC) and length (OEL). The relationships between these indices were evaluated in five pan-contemporaneous Santacrucian Notoungulata genera from Patagonia: Adinotherium and Nesodon (Toxodontia), Interatherium, Protypotherium and Hegetotherium (Typotheria). While OSA, OTA and OEL were size dependent and strongly correlated, HI and ECC were size independent. All notoungulates analysed have very hypsodont teeth, indicating high rates of tooth wear in response to an increase of abrasives consumed with the food; their tooth occlusal area and complexity could be related to chewing efforts associated with the toughness of the plants consumed. HI, OSA and ECC were considered useful for palaeoecological reconstructions, but the results presented here show that these three features are integrated as a complex, so should not be evaluated separately.

The 6845 ± 50 BP climactic eruption of Mount Mazama discharged 47 ± 9 km3 of vertically zoned calc-alkaline magma, affording a virtually complete section through the chamber. Evidence for two andesitic parents with different trace-element (particularly Sr) and water contents is preserved in the ejecta. Prior to eruption, a dominant volume of rhyodacite was underlain successively by high-Sr andesite, high-Sr crystal mushes, and low-Sr crystal mushes. Intergranular liquids in the high-Sr magmas were probably richer in water than those in the low-Sr magmas. Thermal continuity throughout the ejecta favours eruption from a single, zoned reservoir. Insight into chamber development is given by preclimactic rhyodacitic lavas and tephra erupted between about 30,000 BP and the climactic eruption. The oldest of these lavas, contaminated derivatives of low-Sr magma, contain crystal-poor magmatic inclusions of low-Sr andesite; the youngest has inclusions of high-Sr andesite and, like rhyodacitic pumice in the climactic ejecta, is hybrid magma containing an admixed high-Sr component. A model for steady-state growth of the chamber is inferred whereby repeated recharge, first by low-Sr then high-Sr andesite (± basalt), builds up a cumulate succession, while derivative liquid fractionates convectively, segregates, and mixes with an incrementally growing silicic volume. The magma chamber at Mount Mazama may provide insight into the evolution of some granitoid plutons.

The mumps, or what I beg leave to call angina maxillaris, is an epidemic disease of a very singular nature. It has appeared sometimes to be pretty general; but this has not been the case for many years in this place. It seems to be analogous to, if not the same distemper with that called the branks, by the common people in Scotland. In the general account of epidemics, in the first volume of the Medical Essays of Edinburgh, a disorder is mentioned which seems to have been a flight degree of that which is the subject of the following paper. I have had much practice in this disease, and indeed was once reduced to the utmost danger by it myself.