The main interest in the healing of an injured nerve centres, naturally, on the regeneration of the axon. As the birthplace of the new fibres the central stump has attracted and received considerable attention, and the histology of the peripheral stump has been very fully investigated, particularly by Cajal (1928), and more recently by Young (1942), Weddell and Glees (1941), and Holmes and Young (1942). In contrast to our accurate knowledge of conditions in the central and peripheral stumps, there are scant records of the progress of repair at the injured region when the lesion results in the total destruction of the nerve fibres.

In the course of experiments on rabbit sciatic nerves designed to test the effect of interference with the blood supply on the regeneration of injured nerve (Bacsich and Wyburn, 1945 a and 1945 b) total degeneration was accomplished by a severe crush with artery forceps. This gave us an opportunity to study the early histological changes in the crushed areas of these nerves.

The patterns of movements of indigenous and displaced trout (Salmo trutta) in a small loch were obtained by ultrasonic tracking techniques. Comparisons of these were made by developing stochastic simulations of their movements based on an analysis of the frequency distributions of step lengths, angles of turn and the percentage time spent actively swimming.

The dispersal and escape of displaced fish from an unfamiliar area of the loch can be explained principally in terms of random turning. Nose plugging appears to influence the distribution of the angles of turn without significantly altering the time taken to escape and return home.

Indigenous trout show a strong preference for turns of 180°, indicating a tendency to turn in their tracks. Although a simulation of the indigenous fish shows slower dispersion than displaced fish, it is insufficient to explain the containment of movement within a home range. It is probable that successive steps are not independent and there may be some association between step lengths and subsequent angles of turn. The implications of their autocorrelation are discussed.

The definition of the name “kylite” is reviewed and it is suggested that its usage should be discontinued. What is now emphasised as the criterion of most importance in distinguishing “kylites” from crinanites and teschenites is the development of a strongly zoned purplish pink augite in advance of feldspar. Basic alkaline doleritic rocks in which the augite develops in this manner could be referred to simply as kylitic. Specimens were systematically collected from the picritic sill near Dalmellington which is kylitic in type. Rocks from different levels in this sill have been chemically analysed, and also unzoned olivine (Mg74.4) and zoned augite. A vein (and the augite from it) in the kylitic sill near Troon, known as the Hillhouse Quarry Sill, have also been chemically analysed. The chemical compositions of all these analysed rocks and of the analysed augites are compared with appropriate data from, in particular, the sills of the Shiant Isles and Lugar, and the Black Jack Sill in New South Wales. Some relationships of kylitic rocks with the differentiation trends in these sills are briefly discussed with the aid of variation diagrams. On the basis of the available evidence it is inferred that in the olivine-rich Dalmellington Sill, olivine has accumulated prior to intrusion and that subsequent “flowage differentiation” has apparently been inoperative.

Although common seals (Phoca vitulina L.) do occur in the Firth of Forth, the grey seal (Halichoerus grypus Fab.) is by far the most abundant species in the area. Some pups are born along the north shore of the outer firth but the vast majority are born on the Isle of May. This colony has increased in size from less than twenty-five pups in 1975 to more than 900 in 1986. Studies using conventional and radio tags indicate that many of the seals at the Isle of May originally came from the colony at the Farne Islands, off the Northumberland coast. Information from the Fame Islands population is used to predict future changes at the Isle of May. If current trends continue, more than 2000 pups could be born each year by the end of the century. However, it seems unlikely that this will occur. Management methods for controlling habitat damage are discussed.

A detailed consideration of the morphology, peritoneal and topographical relations, blood supply and certain aspects of the histology of the alimentary tube are considered in these two rare lemurines, the anatomy of which has hitherto been very incompletely known. Evidence is presented of the structural apartness of Hapalemur from Lepilemur and Lemur and therefore for its separation in a separate subfamily of Lemuridæ. Differences between Hapalemur and Lepilemur are seen in the stomach, cæcum, colon, spleen, liver and gall-bladder. The resemblance of the spleen of Hapalemur to that of the marsupials proclaims its primitive status, while the fissuration and relative sizes of the main hepatic lobes show noteworthy differences in the two genera. In some respects Hapalemur approaches the Cheirogaleinæ, but cannot be included by definition within that subfamily.

Grain stored in bulk forms a man-made ecosystem with a limited, non-regenerating energy supply. However, frequent interference results in an immature, unstable ecosystem with a relatively simple structure and composed of species with limited specialisation, and high growth and reproductive rates. Microbial colonisation commences soon after ear emergence, by what have been termed “field” fungi. These usually have a minimum water potential for germination of −22.4 MPa (> 0.85 aw), have to contend with large diurnal changes in environmental conditions and seldom develop further in store. Sometimes, especially in humid tropical climates, species more typical of stored grain (“storage fungi”) also develop before harvest, and even produce mycotoxins. This differentiation between fungi characteristic of field or store is historical and their classification on ecological requirements would be preferable.

In this paper the subject of faunal zonation in the ocean floor from the intertidal, and over the continental shelf, slope and rise and to the abyssal plain is examined on the basis of faunal change at the generic and species level. The region investigated over a period of five years aboard R/V Eastward is a Beaufort-Bermuda transect, approximately 75 kilometres wide and 500 kilometres long and bounded between 32° and 36°N latitude and 64° and 79°W longitude. A new method, involving numerical indices reflecting changes in the composition of taxa, endemism and diversity between adjacent depth levels, was developed for defining faunal boundaries. Isotherms and isobaths utilised by earlier authors for characterising deep-sea boundary on a global scale do not coincide with natural faunal boundaries. This study analyses the vertical distribution of 128 species of isopod crustaceans and 28 species of large epibenthic invertebrates. The zonation patterns seem to correspond with correlations in environmental conditions such as currents, topography and sediments.

We suggest four major vertical faunal provinces, characterised at the generic level, namely (1) the Intertidal Faunal Province; (2) the Shelf Faunal Province; (3) the Archibenthal Zone of Transition; and (4) the Abyssal Faunal Province and internal zones within these characterised at the species level. The main aspects of interest include the presence of a narrow ‘meso abyssal zone’ with a species maximum, the demonstration of the true transitional nature of the Archibenthal Zone in biotic and abiotic factors and the characteristic low-biomass Red Clay environment showing definite faunal isolation from the continental margin.

The meagre history of the study of the fungi of birchwoods in Britain is offered as an introduction to more recent studies in the British Isles and in continental Europe. Four categories of fungi (parasites, suspected mycorrhizals and lignicolous and humicolous saprophytes) are recognized and discussed. Examples of the most frequently found species-associations are given in relation to environmental factors.

Three main types of Hebridean freshwater lochs occur in the Loch Druidibeg National Nature Reserve; eutrophic calcareous machair lochs near the Atlantic coast, mesotrophic lochs on the edge of the moor and oligotrophic lochs on the peatlands. Chloride/calcium concentrations, highest in lochs near the sea, fall away rapidly inland and are lowest in the moor lochs. The fauna of eutrophic and mesotrophic lochs includes a few euryhaline brackish-water species Potamopyrgus jenkinsi, Diaptomus wierzejskii, Neomysis integer and Gammarus duebeni. G. duebeni alone penetrates the oligotrophic lochs. Freshwater sponges are widespread but are absent from the machair lochs and there are no triclad planarians. The fauna of fast and slow stream segments is described. Loch Bee, a man-made lagoon, unlike the open brackish lochs of North Uist, is an unstable habitat and its fauna has changed considerably since it was investigated in 1933. The fauna consists mainly of brackish-water species and a few stenohaline marine species which are confined to its seaward ends. The sequence of faunistic change in the Howmore estuary, Lochs Roag and Fada, a Site of Special Scientific Interest (SSSI), is described; the brackish-water fauna is reduced by the volume of fresh water passing through the system. A brief account is given of the unusual dominance of Hyalinella punctata and Potamopyrgus jenkinsi in Loch Ardvule (SSSI), South Uist.

Coprophilous fungi form an easily recognised ecological group adapted to severe disturbance. They survive as spores on herbage and are ingested, chewed, subjected to digestion, exposed to competition within the gut, egested and then suffer further competition and environmental variation. Studying the ecology of fungi on rabbit dung has several advantages, both for research and teaching. These include ready availability, ease of replication, simple techniques for varying the environment and levels of competition, and the possibility of adding spores to sterilised food. This is illustrated by studies on three aspects of the ecology of coprophilous fungi.