The variability of the pubescent birch and the probable existence of hybrids between it and two other birches make it a difficult species to classify at an infraspecific level. To some extent, the variation is geographical and to cover its distribution, three subspecies are proposed by the authors of Flora Europaea, sspp. pubescens, carpatica and tortuosa. Two subspecies are recognized in Britain, namely ssp. pubescens and ssp. odorata, but some confusion has arisen through the undetermined relationships between sspp. odorata, carpatica and tortuosa. The rejection of ssp. odorata is proposed as its application, in this case, differs from that intended by J. M. Bechstein, the original authority. An examination of the literature indicates that ssp. tortuosa and ssp. carpatica are probably indistinguishable (a conclusion supported by multivariate analysis) and that the epithet tortuosa can be applied to both taxa. The pubescent birch in the Scottish Highlands may be referred to ssp. tortuosa and, in addition, the high frequency of small-leafed individuals in some populations in the northwest and at higher altitudes, justifies the further distinction of var. microphylla Hartman.

The concept of heritability is discussed in relation to the climatic changes which may affect the variations of age at sexual maturity in the fowl, and it is suggested that genetic and environmental variance, as expressed in the customary statistical formulation, may be largely synonymous terms.

Four groups of Brown Leghorn pullets are compared, one subject to no artificial lighting and the sub-optimal conditions of war years, a second to restricted lighting, and a third and fourth to 14-hour day length. The formal estimates of genetic and environmental variance were respectively 910 and 978, 594 and 546, 188 and 295, and 56 and 135. Further reduction of variability is apparent on subdivision into early and late hatches, heritability being apparently zero in the first case but maintained at an average level in the second.

Changes in variability substantiate the presence of genotype-environment interactions as previously reported, and similar conclusions follow from heterogeneity of regressions of age at maturity on date of hatch.

The visit of Commander Perry's American fleet in 1853, followed by visits of European oceanographic research vessels, initiated Japanese interest in oceanography. Fortunately, because of a long maritime history and experience, such advanced sciences were speedily and easily absorbed in Japan. The U.S.S. Tuscarora (1874) discovered the Tuscarora Trough in the Japan Trench during her trans-Pacific sounding cruise as a preliminary to laying a submarine cable. During her epoch-making scientific expedition around the world (1872–76) the British Challenger visited Japan in 1875 and surveyed parts of the Inland Sea. This was followed by the Swedish Vega Expedition (1879) which first cruised across the Arctic Ocean to Tokyo, the Russian Vitiaz Expedition (1886–89) in the Japan Sea, etc., and the USA Albatross Expedition (1888–97) in the northern waters and Japan Sea.

Spruce plants (one clone of Picea abies (L.) Karst.) were exposed in environmental chambers to different levels of ozone for 42 days to study the influences of enhanced ozone on root tip chromosomes directly after fumigation had ceased. No visible symptoms resulted from these treatments. The classification of chromosomal aberrations was used as a method to characterise the influences on the root tips caused by ozone. In comparison to the control the fumigated variant showed an increased number of chromosomal abnormalities. Another clone of Picea was used to investigate the ‘post-fumigation long-term effect’ in the genetic material caused by enhanced ozone. These clonal trees appeared to be relatively ozone-sensitive, as pigment reduction and chlorotic spots were observed directly after fumigation had ceased. The spruce trees were also exposed in environmental chambers to different levels of ozone for 24 weeks and then they were transferred to a field near the Institute. Some 21 months after the fumigation had ceased those trees that had been fumigated showed an increased number of chromosomal aberrations compared with the control.

The observed chromosomal abnormalities in all the variants of the experiments consisted of chromosomal ‘stickiness’, chromosome breakage, and fragmentation.

Modern ship routing is a matter for specialist forecasters using a mass of meteorological observations processed by large, high-speed electronic computers, as will appear below.

Historically, some form of routing has been practised for centuries as the result of observations made by navigators and explorers as they gradually laid bare the geography of the earth's oceans and continents.

It cannot be known whether the very early navigators followed routes based on weather considerations, but they may have done so in limited areas of the globe. There is some reason to suppose that the Atlantic islands and even perhaps the West Indies were known to the Phoenicians. Legends which suggest this are supported by the finding of a stock of fourth century b.c. Phoenician coins at Corvo in the Azores. It has been reasonably supposed in some quarters that these coins were from a Phoenician trader wrecked on the island whilst on passage westwards, but how far west we cannot be sure.

It has never been seriously doubted that the north-east coast of America was discovered and temporarily colonised by Vikings from Greenland during the latter part of the first century A.D. Certain archaeological finds have been held by some to support this view. An account of some early pioneering voyages has been given by Villiers (1956).

These early voyages can hardly have been consciously weather routed, though some knowledge of the prevailing wind conditions may well have been acquired. Perhaps it was as late as the end of the fifteenth century that the first known weather-routed voyage was made. Henry the Navigator (Prince Henry of Portugal) was intent on finding a way round the Cape into the Indian Ocean in order to oust the Venetians and Arabs from their lucrative trading in that area. He fitted out expedition after expedition, but they all turned back as they hugged the African coast and were caught in the doldrums. Eventually they learned to stand well out to sea and so get the benefit of the N.E. trades and in 1434 they reached the equator. However, it was another half-century before the Cape was reached and this could conceivably be regarded as the first weather-routed voyage.

Electroencephalography has added another important means of investigation of cerebral activity and functioning to the many others previously at our disposal. In applying it, as with the other investigative methods, it is important that we should have clearly in mind exactly what facts it is able to demonstrate and what interpretations we are justified in making of the observed facts. This process of interpretation is difficult partly because it is a two-stage one; the electrical potentials observed are those on the surface of the scalp and these must first be referred back to potential sources (i.e. electrical charges) in the brain itself. These latter must then be interpreted in terms of activities of nerve cells and nerve fibres. The first of these two stages belongs entirely to the sphere of mathematical physics, and the present paper is an attempt to present a working hypothesis which not only suggests a solution of this stage of the problem, but suggests a probable solution of the second stage. The second stage properly belongs to the sphere of physiology, but progress here is rendered difficult by lack of decisive knowledge as to the nature of the elementary unit of central nervous activity.

Present knowledge of long-term changes in benthic species in the Firth of Clyde is reviewed.

Recent work on the annual variations in seasonal cycles of the sand-dwelling bivalve Tellina tenuis da Costa shows some correlations with natural and man-made variations in seawater temperature. Between 1973 and 1984 inclusive good settlements of young occurred on the two beaches examined in the autumns of years when higher mean seawater temperatures occurred in June and July. The implications are discussed in relation to cycles of climatic change. In general, settlements at Hunterston, a thermally enriched area, were considerably greater than at Kames Bay, a site affected only by natural temperature changes. However, T. tenuis at Kames Bay grew to much larger maximum sizes than at Hunterston, except in 1979, when Hunterston animals were larger. The possible interactions of food availability and the modifying effects of heated discharges are discussed.

Earlier results by Dr A. C. Stephen between 1926 and 1951 are reassessed in the light of present knowledge.

The history of Edinburgh's sewage disposal to the sea from the open ditch system of the 17th century to the present day, together with the changes in legislation affecting sewage discharges to the firth, are reviewed. During the last thirty years sewage discharges have been monitored monthly for levels of faecal coliform bacteria at approximately thirty-four shore sites and twenty offshore sites. These coliform counts are used as bacteriological indicators of sewage pollution, in order to assess the risk to humans of infections that might result from the consumption of contaminated shellfish or from bathing in sewage-polluted waters. Most of the areas sampled from the inner firth were shown to be grossly polluted, particularly in late summer, and regularly to exceed guideline levels throughout the year. Since the commissioning of the new Seafield sewage works in 1979, a general improvement in bacterial and viral counts has been recorded on the south shore of the inner firth. In the last decade two European Community directives relating to the quality of seawater for bathing and shellfish growing have been promulgated, which set guideline and mandatory levels for the number of faecal coli in seawater. The Scottish Development Department has recently designated five beaches as bathing beaches and two areas on the north and south shores of the firth as shellfish growing areas. These areas have been regularly monitored by the Forth River Purification Board and the published results of both surveys are analysed. The virological studies carried out by the Forth Pollution Group of Napier College before and after the major change in the sewage discharge pattern into the Firth of Forth are reviewed.

Maps are shown to be the most striking way of displaying the distribution of marine species on a geographical scale. They have been used to indicate not only the presence or absence of a species, but also its abundance. A single map only records the distribution pattern at a particular moment in time, but repeated mapping clearly demonstrates temporal fluctuations. Many ecological insights have been derived from distribution maps especially when they are compared with records of environmental factors such as substratum type, current velocity or temperature. Moreover maps actually stimulate experimental work which seeks to explain the distribution patterns displayed.

Plant biotechnology can serve industrial concerns in two ways; it can lead to new products and to new ways of producing an existing product (i.e. ‘processes’). The technology can be used in any business involved in using or selling plant products. In the agricultural input business molecular genetics is having most effect on the introduction of new variation into crop plants. The first products are likely to involve the introduction of insect and disease resistance and herbicide tolerance; some genes transferred will change product quality. Future applications will involve the control of more complex traits. Biotechnology will also enhance plant breeding via improved technologies (e.g. RFLPs and tissue culture); also the production of hybrids is likely to be enhanced and extended. Early products will also include the production of rDNA microbial products for control of pests and diseases.

Of considerable concern to businesses is whether or not they can make sufficient financial return on plant biotechnology. The reasons behind this concern are the time it takes to introduce a product to the market; the expenditure on meeting regulatory requirements; the overall level of public acceptance of the products and the level of return from the farmer. To ensure a fair return on investment there also needs to be a secure structure of intellectual property protection (patents, plant breeders rights, etc.). Continued success in the application of plant science to agricultural improvement depends on a proper economic environment as well as the advancement of the science.

A wide variety of normal and malignant mammalian cells, as well as inflammatory cells, release extracellular active oxygen species such as superoxide and hydrogen peroxide. Both these species at low levels can stimulate growth and growth responses in a range of normal and malignant cell types. In order to assess the significance of such findings, superoxide dismutase and catalase were added exogenously to the culture medium of hamster (BHK-21) and rat (208F) fibroblasts (non-transformed or oncogene transformed). This resulted in a reduction of cell proliferation and increased cellular uptake of trypan blue stain, suggesting that superoxide and/or hydrogen peroxide may have important roles as extracellular ‘messengers’ promoting cell proliferation and maintaining cell viability. Superoxide dismutase mimics, like superoxide dismutase itself, are also cytostatic towards these cells and provide a basis for the development of tumour-specific antiproliferative drugs.

Sand dunes occur extensively around the coastline of Great Britain and in a wide variety of forms. Management for nature conservation is influenced by a long-term historical perspective which has led to a continued policy of protection. It has aimed firstly to prevent damaging developments such as building and orestry, and secondly to control excessive erosion brought about predominantly by man's own activities. However, an assessment of current nature conservation management problems suggests that at many sites in Great Britain over-stabilisation may be as much a problem as erosion. The implications for management in the face of other competing demands is discussed.

Previous work has shown a sex difference dependant upon œstrogen-androgen balance, in the rate of clearance by the fowl liver of intravenously administered sodium bromosulphthalein. Further observations reported here indicate an apparent rapid fluctuation of the Œ-A balance which takes place in immature chickens, both sexes snowing what is interpreted as hyperœstrogenization about the age of twelve weeks. Attention is drawn to other evidence that profound metabolic and hormonal changes occur at this stage. The effect of exogenous sex-hormones on the clearance rate of BSP has been further studied, particularly the influence of extra androgen on adult males with aberrant clearances unassociated with liver lesions. More evidence for the relation between the rate of BSP clearance and the Œ-A balance is provided by the study of the effect of cessation of ovulation on the clearance, and the effect of the development of virilizing tumours at the site of the rudimentary right ovary after left ovariectomy. Other changes which confirm hyperœstrogenization as assessed by the BSP clearance test are (a) decrease of the packed cell volume, (b) the development of a precipitable phospholipid in the plasma, (c) renal vascular changes, (d) adrenal cortical hyperplasia, (e) a frequent association with oviduct ligament “fibroids” and persistent cystic right oviducts.

The epidemiological approach to the investigation of breast cancer is briefly described with special reference to case-control and cohort studies. Risk factors for breast cancer are then reviewed, paying particular attention to menstrual and reproductive factors and to body weight. Some of the hypotheses which attempt to draw the epidemiological observations together are also outlined.

The effects of exposure to exogenous oestrogens are considered in more detail. There is evidence from one study that the administration of large doses of stilboestrol during pregnancy increases breast cancer risk after a latent interval of about twenty years. Conjugated equine oestrogens administered to postmenopausal women may also slightly increase breast cancer risk after prolonged use. Little information is available about the effects of any other type of “hormone replacement therapy”. Combined oral contraceptives do not appear to have any general effect on breast cancer risk, but prolonged early use, especially use before first term pregnancy, may be harmful to the breast.

The herring population inhabiting the Firth of Clyde has supported an important fishery for hundreds of years. The basis for this fishery was until recently a stock of spring-spawning herring which spawn on Ballantrae Bank in the period February-April and which was investigated intensively by means of larval surveys from 1958 to 1979, when it had decreased to a very low level. In the late 1960s there was evidence of a change in the composition of the landings and during the 1970s and in the present decade the majority of fish caught have been of autumn-spawned origin. There is no evidence of significant autumn-spawning in the Firth of Clyde and autumn-spawning herring in advanced stages of maturation appear to leave the Clyde, returning by the time the fishery opens the following spring.

The spawning origin of autumn-spawned herring in the Clyde has been investigated by tagging experiments, and recaptures have been made in the Irish Sea, off the northwest Irish coast and further north along the west coast of Scotland. However the spawning area of the majority of the fish is unknown.

The herring fisheries in the Clyde, originally carried out by ring-net and anchored drift-net but now mainly by pair-trawl, have been managed by closed seasons and in the past few years by total allowable catch regulations under the control of the European Community.

There is also a population of sprats in the Firth of Clyde which supports a small fishery and spawning of this species takes place earlier in the Clyde than elsewhere around Scotland. Mackerel also make annual incursions into the Clyde and support a small summer fishery. Factors affecting the abundance of pelagic fish species in the Clyde are discussed.

Information concerning the carcinogenicity of bracken fern (Pteridium aquilinum) in different species and organs is reviewed. Various methods used in attempts to identify the plant components responsible are described and the results evaluated. Reference is made to recent and current research in this field (University College of North Wales, Bangor) and includes mutagenic and sterility studies, and the introduction of teratogenic screening by injection of Japanese quail eggs. The many problems still challenging bracken workers are indicated, and a final section deals with the potential hazard to human health in an attempt to link experimental work with epidemiological surveys of human cancer incidence. One important result of the study of bracken carcinogenicity is that active components, previously thought to be harmless, can be found in a wide variety of regular dietary items.

Ectoparasites of poultry in the United Kingdom are reviewed. Mention is made of poultry ectoparasites occurring in other parts of the world and of some ectoparasites of British birds. In south west Scotland ectoparasite infestations appear to have decreased following the intensification of the poultry industry. Occasional outbreaks of Dermanyssus gallinae, the red mite and Ceratophyllus gallinae, the hen flea have occurred in modern poultry units. Cases of louse infestation with Menacanthus stramineus have also been observed from farmyard chickens and bantams. The damage caused by ectoparasites and their role in disease transmission is discussed.

Skin diseases of poultry caused by bacteria, fungi and viruses are reviewed. Skin conditions not induced by trauma are extremely rare in south west Scotland. Traumatic induced skin diseases still occur in modern poultry units and are associated with fighting or the use of poor materials in the structure of the house. Cases of staphylococcal wound infection and staphylococcal arthritis have been observed in poultry units where poor quality wire netting or hard spiky litter have been used as floor materials. Mention is also made of two pigeon diseases, pigeon pox and canker.

A large number of density measurements of the more important rock-types exposed at the surface in Ayrshire and certain neighbouring areas provide information for the interpretation of gravity measurements. The three methods employed of determining density are (1) laboratory measurements of rock samples, (2) gravimeter measurements in mineshafts, and (3) gravimeter measurements over topographic features.

The first method, the most widely used, is the only one applicable to many of the geological formations. A total of 600 specimens measured cover all the common rock types of the Lower and Upper Palaeozoic systems and their associated igneous rocks. Use of the second method is restricted to Carboniferous rocks, in which records from four mine-shafts—Littlemill 5, Mauchline I, Auchincruive I, and Houldsworth—cover much of the Carboniferous succession in south Ayrshire. The third method was seldom applied as there are few suitable topographic features, independent of geological structure, in Ayrshire.

The results of the measurements are summarized, and their reliability discussed. Two contrasts of rock density of regional importance occur in the sedimentary succession of south Ayrshire—the first at the plane of unconformity between Upper and Lower Old Red Sandstone, and the second between Lower Old Red Sandstone and the Lower Palaeozoic greywackes. A marked contrast of local importance occurs between the Permian sandstones of the Mauchline Basin and the underlying lavas and Carboniferous rocks. In north Ayrshire the most important density contrast lies between the Upper Palaeozoic sediments and the associated dense igneous rocks—the Clyde Plateau Lavas, the Millstone Grit lavas, and the thick dolerite intrusions.

Bracken in Britain is a host for 27 species of insect herbivores, with a further 11 species that either feed below ground (and are poorly studied), or appear to be only rarely associated with the plant. A typical site in northern England has an average of 15–16 of these species in any one year. Compared with perennial herbaceous angiosperms with similar wide distributions, bracken is not noticeably depauperate in the number of insect species that feed upon it. Bracken in others parts of the world is attacked by a wide variety of insects, with more species present in the geographical areas where bracken is most common.

The ‘feeding niches’ of some of these insects are reviewed. Most are very rare relative to the biomass of their host plants, probably because of the impact of natural enemies; the effect of most of the insects upon their host-plant is consequently negligible.

Reverse effects, of host-plant upon the insects, are subtle but poorly understood. Experiments to elucidate these effects are briefly outlined.

There is considerable interest in the cultivation of salmonids in several countries. In Norway it is now a question of rate of expansion rather than a question of whether this industry will develop or not. Interest is turning more and more towards sea farming based on Atlantic salmon rather than on rainbow trout.

One of the most important economic factors in fish fanning is the producing ability of the fish. It is essential for the future expansion of fish farming that one develops a more productive animal which is better adapted to captivity.