Betula is well represented in the Pleistocene deposits of the British Isles; B. nana is often recovered from glacial sediments and tree Betula flourished early and late in the interglacial periods. In western and northern Britain, tree Betula has remained important in the forests since the last glacial period.

Two aspects of the relationship between macroalgae and their environment are considered.

Firstly, the serious deterioration of algal populations in the Joppa area is examined, comparing recent studies with those of G. W. Traill, an active phycologist working on the marine algae of the Firth of Forth in the nineteenth century.

The second aspect of the paper is an assessment of the contribution by macroalgae to estuarine ecosystems. The path of photosynthetically fixed carbon through the growing macroalga, and the various ways it enters the water receive particular attention.

Marking experiments have demonstrated that certain of the rings appearing as surface sculpture on the shells of the lamellibranch Venerupis pullastra are valid as a measure of annual growth. From measurement of these rings the mean monthly and the mean annual growth increments have been calculated. The length-age relationship curve is similar to that of most other lamellibranchs. Reasons for the variation in the mean monthly rate of growth have been examined. The height-length and the thickness-length ratios for various sizes have been calculated and found to follow a simple and direct tangent relationship.

This paper considers the evolution of the concept that the local distribution of animals in the sea is largely determined by the habitat preferences and behaviour of the animals themselves. Examples are mainly taken from studies on invertebrate animals. Nineteenth-century investigations on the behavioural responses of micro-organisms to such variables as light, salinity and oxygen, stimulated analogus investigations on the behaviour of marine invertebrates. From 1920 onwards, various lines of research have developed, notably on the settlement of marine larvae, but also on habitat selection by adult planktonic and benthic invertebrates, and on host finding by parasites and commensals.

Attention has been drawn to the relevance of genetic studies on behaviour, and to the significance of investigations on terrestrial animals. A synoptic view of habitat selection has been advanced in which animals respond to a complex of interacting stimuli from their physical, chemical and biological environment.

Simple models have been presented which consider the influence of dilution of the preferred habitat by less preferred alternatives, alteration of the rate of change of a habitat, the relation between habitat preferences and lethal limits, and the colonisation of new habitats.

Massive calcareous rocks and stones support lithobiont communities of bacteria, fungi, cyanobacteria, lichens, and phanerogams in most parts of Israel. The distribution of these communities is influenced by environmental conditions. Moisture regime of their substratum is the most important factor. Many of the lithobiont communities cause typical patterns of weathering that may be preserved on the rock surface or inside the rock for thousands of years. Knowing the climatic affinities of the lithobiont communities, one can use the uncovered in situ rocks and stones and those that were buried in the past as fossil climate recorders. With this method, the following deductions have been made about palaeoclimates in our area: (i) the wettest period ended 30,000 years BP; (ii) a period drier than the present took place sometime between 10,000 and 30,000 years BP; (iii) the Neolithic Period (9,000–10,000 years BP) was much wetter than the present; (iv) since the Chalcolithic Period (5,000 to 6,000 years BP) the climate of Israel has been similar to that of the present.

The results of a phase I/II study in advanced breast cancer in postmenopausal women of the aromatase inhibitors 4-hydroxyandrostenedione (40HA), miconazole and CGS16949A are described. 40HA, a steroidal compound which is an irreversible inhibitor of aromatase, has been administered to 131 patients by weekly (500 mg) or fortnightly (250 mg) i.m. injections, and daily (500 mg) by mouth. The overall response rate (complete regression (CR) and partial regression (PR)) was 33%; all three dose schedules had similar clinical efficacy. Oestradiol levels were suppressed to a mean of 37–45% of pretreatment values with oral and with weekly i.m. 40HA; suppression was marginally suboptimal with 250 mg i.m. fortnightly. 40HA was well tolerated, especially when administered by fortnightly injections; this dose schedule is to be preferred to weekly injections.

Significant oestradiol suppression and clinical responses did not occur with the imidazole antifungal, miconazole, which was administered to twenty-two patients at doses of 500–1000 mg daily. The non-steroidal aromatase inhibitor, CGS16949A, induced comparable oestradiol suppression to 40HA at doses of 0.6–4 mg daily; 0.6 mg daily appears to be suboptimal. Five of thirty-one patients treated had objective responses, and disease stabilised for at least six months in nine patients. Some suppression of aldosterone occurred with doses of 2 and 4 mg daily, but clinical toxicity of the compound was minor.

Betula nana L., the dwarf birch, is shrub-like in habit. Today it has a relict distribution in the north of Britain. In the Early Post Glacial period, it was widespread throughout Britain. This paper reviews the present understanding of the species in our flora and describes aspects of its morphology, palaeoecology, current distribution, habitat and hybridizaton with the arborescent birches.

Numerous investigations have already been made on the biology of Calanus finmarchicus. The main body of data, however, has been derived from field observations, and while many and important conclusions have been drawn from such work, confirmation of some of them is required by direct experimental methods. Accurate studies on the feeding, metabolism, and breeding of Calanus can only be made on living animals in the laboratory. Some such investigations have already been made by Crawshay, Clarke, Fuller, Marshall, Nicholls and Orr, Harvey and others, but the results have sometimes been obscure owing to the difficulties encountered in keeping Calanus in really healthy condition.

The River Tay and its estuary is one of Britain's largest and most important aquatic systems. Rising at 625 m and flowing for 148 km the River Tay is the largest by flow in Great Britain and has a catchment area of 5031 km2. There are considerable ecological changes from source to estuary. These take the form of transitions, but four main aquatic communities can be recognised: an upper, base-poor, swift-flowing alpine section, then an oligotrophic section with moderate flows at lower altitude, next a much richer, slower flowing, more lowland stretch and finally the upper estuary itself. The problems of classifying and conserving running water systems are discussed and the importance of the Tay system is emphasised. The linear form and catchment size of larger rivers makes it difficult to give them—particularly their lower reaches and estuaries—full conservation protection. The River Tay is sufficiently unique, both physically and biologically, to warrant further scientific investigation and nature conservation protection.

The hydrography of the Forth estuary is described, and various modelling studies that have been carried out are briefly summarised. The description of the hydrography includes information on the currents, salinity, temperature, tidal elevations, and turbidity, as well as physical dimensions and freshwater inputs. The vertical salinity structure of the estuary varies from the well-mixed state to the partially-mixed state, depending on the freshwater input and the tidal range (which determines the amount of turbulent kinetic energy available for mixing). The tides in the estuary exhibit double high and low waters because of shallow-water effects, and there are observations of a small tidal bore. The resuspended solids are found to account for a large fraction of the biochemical oxygen demand in the water column. The modelling studies range from an early physical model, to an analytical model of water-quality, to more recent numerical models produced by the Forth River Purification Board and Imperial Chemical Industries, which were developed in order to assess the impact of proposed discharges on water-quality. Finally, currently active projects are described and suggestions for future work given.

Most of Sinai belongs to the Saharo-Arabian phytogeographical region. It is covered with a sparse vegetation of semishrubs, restricted to wadis or growing on slopes of rocky hills and in sand fields. The high mountains of southern Sinai support a mainly Irano-Turanian steppe vegetation. Smooth-faced rock outcrops supply sufficient run-off water to permit the survival of trees, shrubs, many relict species, and most of the endemics of Sinai. There are 28 endemic species in Sinai, of which 25 occur in the mountainous districts of Sinai. The foothills of eastern Sinai and the coastal area of the Gulf of Elat have a savanna-like vegetation and support thermophilous Sudanian trees and shrubs in wadis and rock crevices.

The basic premise that foraminiferal test morphology is related to function, in this case life position and feeding strategy, and thus indirectly to habitat, is detailed in Jones & Charnock (in press). The following account is based on that work but is in the form of a summary since a detailed description will be published elsewhere. The information used in this paper is from Pearce (1980) who examined Foraminifera in semi-quantitative multiple cores collected in a series of transects running approximately perpendicular to the axis of the Rockall Trough. The Foraminifera were from the surface sections, 0-2 cm, of the cores.

The structure and diversity of fern spores, based on SEM studies, are assessed in relation to general evolutionary trends and systematics. A review of spores of myrmecophytic ferns includes SEM figures of eight species and the ant Iridomyrmex cordataus. The diversity, especially in Lecanopteris spores, is correlated with other characters indicating systematic differences of the species. Convergence is shown in the echinate spores of the neotropical Solanopteris and those of the paleotropical Drynaria and Selliguea. Evidence for adaptation of spore structure to transport by ants is especially clear in the development of filamentous elements, unique among pteridophytes, in Lecanopteris mirabilis. These demonstrate an unusual labile nature of the wall, and provide insight into the functional role of intricate surface formation of spores.

Water economy is a necessary complement of terrestrial life, for the limits of life upon land are, in part, determined by the organism's ability to utilize and conserve the water of its environment. For small organisms of terrestrial habit, the large surface-to-mass ratio and consequent surface evaporation makes the problem of water conservation particularly acute. It is therefore remarkable that the insects constitute the most numerous and varied group of terrestrial animals; and it follows that their success is, in large part, due to their ability to utilize and conserve water in widely divergent environments.

The dependence of plant production in the sea on the presence of nutrient salts, especially nitrate and phosphate, and on illumination has been repeatedly demonstrated. The object of the present work was to find primarily whether, and to what degree, plant and animal production could be increased by adding fertilizers to an enclosed body of sea water under otherwise natural conditions.

Description of a little known anonymous pamphlet, an “Abstract” of the paper read before the Royal Society of Edinburgh, in 1785, in which James Hutton first announced publicly his famous Theory of the Earth. Reasons are advanced for concluding that Hutton himself was the author of the “Abstract”, and that it was published in 1785, some three years before the Royal Society paper was issued in the Society's Transactions. The writer concludes that the “Abstract”, and not, as has hitherto been supposed, the Transactions paper, constitutes the first form in which The Theory was published. The “Abstract” is reprinted in small type on p. 380.

Genetic variation within a crop species is often limited and restricts improvement by conventional breeding methods. This is particularly true for environmental stresses, both biotic and abiotic. Wild relatives of crop plants, however, provide a rich source of novel variation which can be introduced into the crop. Many alien genes for biotic stress resistance have already been introduced into crops; in contrast, the genetic control of abiotic stress tolerance is poorly understood. Genetic engineering of abiotic stress tolerance in the Triticeae is the main subject discussed here with particular reference to salt tolerance in wheat and barley. Methods of alien gene transfer, including locating tolerance genes and restructuring chromosomes, are described. One of the major limitations in transferring genes for stress tolerance is the lack of good tests for resistance or tolerance which is largely due to the fact the physiological mechanisms involved are not fully understood. Genetic markers provide a new opportunity of detecting chromosome segments carrying desired genes easily and efficiently, and these will become increasingly important as the genetic maps of crop species are expanded. Although many stress genes have been located to specific chromosomes, and some have been mapped intra-chromosomally and their dominance relations determined, there is a great lack of knowledge of the control of these genes at the molecular level. Molecular studies of this type are difficult, but it is anticipated that the limitations will be overcome in the near future.

In feathers of a wide variety of unrelated birds non-iridescent blue and related shades are produced by structures. In these, each colour-producing cell of a barb medulla contains a cavity whose outline tends to parallel the cell-boundaries (‘polyhedral’ cavity).

This contrasts with the situation in some other birds with corresponding colour structures where each medullary cell contains a smaller ‘spheroidal’ cavity left by the pycnotized nucleus.

Three different processes of moulding polyhedral cavities are described which modify the thickness of the colour-producing cloudy medium and possibly represent independent evolutionary trends.

The Moray Firth has been intensively fished for many years and has been of great historic importance to the development of Scottish fisheries. The stocks of exploited species in the firth and their relations to other stocks in Scottish waters are described.

Exploited demersal species include haddock, cod, whiting, plaice and lemon sole. The firth is an important nursery area for plaice, and is the most important plaice spawning ground in the North Sea.

The Moray Firth is also an important nursery area for herring. Evidence suggests that these fish recruit to adult stocks in the Minch. In the early 1960s a pair trawl fishery for sprats started and the firth became the most important sprat fishing area in Scotland. However, recruitment of recent year classes has been too poor to sustain the fishery, which has now been closed in order to protect the juvenile heiring which were landed as by-catch.

The distributions of shellfish species are closely related to the bottom sediments. Landings have become increasingly important as the demersal and pelagic fisheries have declined or moved further offshore. The fishery on the Norway lobster is now of particular importance and the catch per unit effort data do not suggest any decline in stock size. Other exploited species include squid, scallops, crabs and lobster.

The tufted duck was chosen as the subject of an energy study at Loch Leven because it is a diving duck which feeds mainly from within the loch and it is present throughout the year, about 500 to 600 pairs nest annually.

Using data from population counts, breeding biology and feeding studies and the analysis of body and egg composition an energy budget for the population has been computed. The values for respiration, R, are calculated on the basis that ‘existence energy’ requirements are 2·5 × Standard Metabolic Rate. Values for rejecta assume an assimilation efficiency of 75 per cent.

The figures have been presented on a monthly basis as there are wide fluctuations in population size, and therefore energy demand during the year and between years. In 1970 very large numbers of tufted ducks were present on the loch during autumn. The additional demands of these birds over 4 months represent an increase in the annual energy requirements of almost 50 per cent.

Chironomid larvae account for 60 per cent of the food of the tufted ducks at Loch Leven; other important food items are caddis larvae and molluscs (mainly Valvata spp.).

Expressed on a /m2 basis and over a full year the energy demands of the tufted ducks represent a small proportion of the total energy available at Loch Leven. However, water depth and the depth of the food in the substrate reduce the actual availability of the food and probably reduce the usable feeding area to 20 per cent of the total loch area.