Life histories and production of the five common species of Tanypodinae (Pentaneura monilis, Procladius simplicistilus, P. crassinervis, P. choreus and Psilotanypus rufovittatus) in the mud at Loch Leven were measured from March 1971 to March 1972. The methods used to identify each species of larva are described. All were univoltine except Pentaneura monilis which had two generations per year, but the seasonal patterns of the life cycles were different. The average density of third and fourth instar Tanypodinae was 3100/m2 and densities of individual species exceeded 2500/m2 for short periods in Procladius crassinervis and P. choreus. Net annual dry weight production by this subfamily was 2·6 g/m2(57 kJ/m2), with individual species ranging from 1·1 g/m2 (P. crassinervis) to 0·16 g/m2 (Pentaneura monilis). These results are discussed briefly and compared with production estimates for other zoobenthos.

The parents of the three naturally occurring radioactive decay series (text-fig. 1),232Th, 238U and 235U, have existed since the time of formation of the earth and through the process of radioactive decay have continuously generated their shorterlived daughter radio-isotopes. Under conditions where these decay products are not separated from the parents the situation referred to as secular equilibrium may be attained at which the activity ratio of any two daughters in the same decay chain is unity. The time required for the attainment of this situation corresponds to several half-lives of the longest lived daughter nuclide. In a great many instances, however, secular equilibrium is not achieved. Excellent examples of disequilibrium are to be found in the distribution of natural radioactive decay series elements in the oceans and sediments. These situations can be used to advantage in marine geochemistry to obtain information on residence times of elements in the oceans and rates of sedimentation occurring under a variety of conditions.

The distribution of about 80 species of medusae from the Scottish and neighbouring areas over the periods 1935–1939 and 1946–1968 is given. A method of charting has been adopted to give an average picture over the 28-year period so as to reduce as far as possible the effects of variations in annual and seasonal sampling intensity. When the occurrence of a species has, in any one year, been particularly different from the average this has been noted in the text and it is hoped that the average picture given here can be used as a basis for comparison in future years.

The distribution of about thirty species of warm water siphonophores over the period 1947–1964 to the north-west and north of the British Isles is used to give a generalized picture of the path of the Lusitanian stream. These species, which originate much further south, are relatively intolerent to change of environment and the distances they are carried can be associated with the degree of inflow on a yearly and seasonal basis.

Grouping the findings into four series of years over the 18 year period shows an increase in their northerly distribution from 1947 reaching a maximum in 1953 and 1954. This has since been maintained, with annual variations, at least until 1963. It is hoped that the data presented here can be used when comparing future studies of climatic change with the distribution of water masses.

176 liverwort species and 649 moss species are known from SW Asia; the total number of species in the different countries is indicated. Families of outstanding bryo-geographical interest or with endemic taxa are the Aytoniaceac, Frullaniaceae, Ricciaceae, Southbyaceae, Targioniaceae, Wiesnerellaceae, Grimmiaceae, Bryaceae, Fabroniaceae, Funariaceae, Orthotrichaceae, Pottiaceae and Splachnobryaceae.

The “Northern”, Euxine-Hyrcanian, Afromontane and Circum-Tethyan elements and their characteristic taxa are discussed. Emphasis is given to the Circum-Tethyan element and its characteristic species; also to endemic taxa especially in the genera Tortula, Crossidium and Targionia. As in the phanerogams, the bryoflora of the arid parts of SW Asia includes a considerable percentage of endemic species. The published information on the bryophytic vegetation of SW Asia is summarised.

Ecological conditions for intergametophytic mating and interspecific hybridisation in the clubmosses are discussed. Several features, including the number of recorded hybrids, records of gametophyte population densities, and conditions for movement of the male gamete in the soil, indicate that intergametophytic mating in Lycopodium is not especially impeded by the subterranean habitat, as has been commonly assumed. The evidence from one site indicates highly effective spore dispersal, and a greater ecological tolerance than expected for the species involved. Two cases are discussed in which hybrids have been formed between ecologically and/or taxonomically very different parent species, in the absence of one parent sporophyte, or with one of the parent species sporophyte poorly adapted to the hybrid habitat. The protected, relatively uniform, subterranean gametophyte habitat is thought to account for successful gametophyte growth and hybridisation between species of widely different sporophyte ecology.

Bracken grows on sites very suitable for forest tree growth allowing a wide choice of tree species. However, the trend in afforestation is towards poorer soils and the area of bracken land being planted is declining. Bracken will damage young trees and methods of its control are reviewed. Hand weeding still has a part to play, but most weeding of heavy bracken growth is by herbicides. Experiments using dicamba, chlorthiamid, picloram and more recently asulam and glyphosate demonstrate a gradual improvement in the selectivity and cost effectiveness of herbicides. Dicamba can only be used before planting and its use is limited to sites where control over three years is assured. Picloram and chlorthiamid at the rates necessary to control bracken are damaging to conifers. Asulam is selective and can be applied after planting giving good control of the bracken. Glyphosate is more damaging to trees than asulam but its use may be justified where a wider spectrum of weed control is required.

Fouling communities typical of shallow water inshore sites were found at three locations in the Moray Firth. At each, an initial background cover of solitary tubeworms and barnacles was overgrown by secondary fouling organisms. On the piles of Nigg jetty, overgrowth consisted of mussels in the depth range 0–6 m and hydroids, sponges, soft corals and anemones from 6–26 m. Buoys in the approaches to Cromarty Firth were completely covered by a mixture of algae and mussels. Sunlit areas of the float cleaned annually bore a diverse algal cover, whereas uncleaned shaded areas and the freely hanging chain had three-year-old mussels up to 7 cm long. Mussel fouling extended down the chain to within 1 m of the seabed at 26 m depth. Concrete anchor blocks on the seabed were covered with solitary tubeworms and hydroids. Steel piled platforms in the Beatrice Field were completely fouled after four years. Mussels and seaweeds were abundant from 0–5 m. In the depth range 8–35 m the background calcareous layer was overgrown by soft corals up to 10 cm long and hydroids. From 35 m to the seabed at 46 m, soft overgrowth was provided mainly by hydroids and ascidians, with only a few small corals.

Prototypes of the more important contemporary fishing gear were in common use in Ancient Egypt. These included fish harpoons, hooks, hand and longlines, angling, trolling, cast nets, fish traps and baskets of various types, dip nets, weirs, seine nets (with and without pockets) and beam trawls.

The seine and beam trawl appeared successively in the Old Kingdom (ca 2660–2180 B.C.) and Middle Empire (ca 2180–1640 B.C.), while the iron fish hook with barb, shank and eye or flange dates back to the New Empire (ca 1640–1075 B.C.).

Archaeological material relevant to fishing consists of preserved samples, artifacts, models and papyrus scripts as well as relief illustrations in tombs and temple walls of scenes depicting fishing methods and crafts from various Dynasties.

The importance of fisheries in the economy of Old Egypt is demonstrated by the exportation of fish commodities and the imposition of taxes on fishing rights and in the engagement of a large number of the population in fish industry. Fish processing included drying, salting, pickling, fish cake and fillet; various implements used were discovered.

It is suggested that these basic fishing techniques (methods and gear) spread in time, along various routes, from Egypt to other parts of the world.

Changes in the status of fish populations in the Clyde Estuary between Woodhall and Glasgow since 1978 are described and data presented on species composition and distribution, temporal and spatial fluctuations in abundance and biomass and length frequency data for certain species are analysed.

The seaward part of the estuary is colonised by marine and euryhaline marine species dominated by flounder, while the ‘city reaches’ have a fresh water component dominated by three-spined stickleback and eel in addition to several euryhaline species, e.g. sand-goby and saithe.

The extent of biological recovery of the estuary from severe organic pollution can be gauged from the presence now of thirty-four species, including nineteen in the city reaches which were virtually fishless in the mid nineteenth century. The upper estuary is now able to support resident and migratory fish for much of the year, but species composition and abundance are markedly affected by seasonally variable fresh water flows to the estuary affecting primarily dissolved oxygen and salinity, leading to mortalities among resident species and providing a barrier to migrants.

In the late eighteenth century the Scottish Highlands were attractive to travellers eager to test themselves against climatic, dietetic and other deprivations. From the early nineteenth century, the Scots themselves became more adventurous and Scottish medical men, notably Mungo Park and David Livingstone, played a prominent part in the exploration of Africa. In the 1860s Livingstone's prolonged travels through the Dark Continent and his belief that he had conquered malarial fever led to the dispatch of the first Christian Mission to the Zambesi region, a venture which failed largely as a result of the missionaries' ignorance of hygiene and medicine.

The establishment of the European presence in British Central Africa (now Malawi) was accomplished by representatives of the Scottish Presbyterian Churches in the 1870s. This paper examines some of the problems encountered during the ensuing half century. Specific themes include the impact of developments in transport systems; housing and sanitation; hints on suitable clothing; the presence of trained medical personnel in both Mission and Government and their role in the study of tropical disease; use and abuse of alcohol.

The conservational vulnerability of tropical pteridophytes, which make up 80% of the known species, is outlined. Especially threatened are the areas of the world with high percentages of endemism.

We have studied morphological and biochemical aspects of storage reserves and their degradation in fern spores during the germination process. The results presented here are concerned with the fate of lipid, protein and phytic acid. Depletion of lipid reserves and breakdown of lipid bodies was directly correlated with increased activity of glyoxylate cycle enzymes during early stages of germination. Degradation of protein reserves coincided with the depletion of salt soluble proteins (globulins) from the spores and was related to the time when high activity of aminopeptidase and carboxypeptidase was observed. Lipid and protein appeared to play an important role in germination. Phytic acid reserves were present in the spore and were hydrolysed by phytase after germination occurred. This storage material was implicated in growth of the prothallus.

Alnus rubra growing in the field in Scotland is nodulated effectively by local strains of Frankia. Strains which have been isolated from Alnus rubra at Lennox Forest show different growth medium requirements and colony morphology compared with isolates from Alnus glutinosa and several different strains have been isolated from the same locality. Preliminary evidence suggests that some spore negative, northwest American Frankia strains may be more effective than local spore positive crushed nodule inoculum for nitrogen-fixation in Alnus rubra.

On the moderately fertile clay soil of Lennox Forest, a mixed plantation of alternate Picea silchensis and Alnus rubra showed no improvement in growth of spruce compared with pure spruce plots. However, the presence of alder increased upper soil nitrogen status by 585 kg ha ' which approximates the standard 150 kg N ha 'of fertiliser nitrogen applied in practice to nitrogen deficient stands at about 5-year intervals. Although the alder had penetrated the subsoil, there was no apparent effect on spruce rooting depth in the mixed stands in this high clay soil. In addition to nitrogen content, the total phosphorus of the upper soil horizons was improved in the mixed plots by an estimated 3–6 kg ha -1 y 1 and it is suggested that this phosphorus may be brought from the subsoil by the deeper rooting alder and deposited on the surface in its litter.

Although improved growth of spruce in mixture with Alnus rubra is only likely where pure spruce stands are stressed for nutrients, the potential benefits of symbiotic nitrogen-fixation in silvicultural practice make it desirable to investigate other species and provenances of Alnus suited to British conditions, to achieve maximum symbiotic fixation of nitrogen by selection and inoculation with superior strains of Frankia and to include such plants in trials of mixtures on sites where nitrogen-availability may be critical.

The subject is a very wide one and for the purposes of a single contribution some selection is essential. Much might be, indeed has been, said concerning the adaptations relating to sexual and reproductive behaviour in the Primates, notably in a long series of contributions by Zuckerman and his co-workers (especially in his summaries of 1932 and 1933). Attention might also be made to the structural adaptations associated with toilet habits. But I have restricted my remarks to three aspects alone, paying particular attention to behavioural patterns in which I have been personally interested, or structural details which I have myself made the subject of contributions to the literature.

I shall confine myself to I. Adaptations associated with the Arboreal Habit; II. Adaptations connected with Dietetic Habits; III. Adaptations correlated with Social Organization.

Only euryhaline fishes were able to recolonize Outer Hebridean fresh waters after the last glaciation so that inland waters now contain only six indigenous, truly freshwater species; salmon, trout, charr, three- and ten-spined stickleback and the freshwater eel. Parts of some lochs are invaded by the sea at stages in the tidal cycle and some 20 species of marine fish may be found at times in inland waters.

Both salmon and sea trout occur in all the larger freshwater systems and sea trout are also found in many of the minor ones.

The original sea trout gave rise to sedentary brown trout populations similar to those of the mainland.

Fluctuations in the Hebridean salmon catch suggest that the stock is affected by the same factors as those affecting Scottish west coast stocks generally: the vast-majority return to fresh water as grilse, while sea trout stocks have been declining over the last 25 years.

Brown trout and eels are almost ubiquitous. Charr occur in Lewis and parts of North Uist but have not been reported from Harris or South Uist and are now only present as sedentary forms. The three-spined stickleback is more widely distributed than the ten-spined.

Outer Hebridean lochs in general have special scientific value because, unlike many Scottish mainland lochs, they have not been affected by the introduction of alien species and some are still in an unexploited state.

The German professor of physiology, August Pütter, is remembered especially for his theories on the nutrition of marine animals. His major papers, ‘The nutrition of aquatic animals’ and ‘Organic matter in the sea’, appeared in 1907, followed by numerous other papers until 1925. He died about 1935. Ranson (1935,1936), Assistant at the Paris Museum of Natural History, gives the essence of the works of Pütter as follows (translated from the French):

1. Aquatic animals are not able to capture by the means which they possess enough organisms or planktonic materials to cover their nutritional requirements.

2. There is a very large amount of dissolved organic matter in sea water which, alone, is broadly sufficient to sustain the needs of the animals.

3. This soluble organic matter has as its source the activity of algae and bacteria.

4. The fundamental part of the nutritional requirements of aquatic animals is derived from dissolved organic matter; plankton plays only a secondary role.

5. Aquatic animals absorb this organic matter not only by their digestive apparatus which is often rudimentary, but by the whole exterior surface of their bodies and especially by simple epithelial tissues such as the gills.

The programme for ornithological monitoring in Shetland has concentrated on selected species of cliffnesting seabirds and inshore waterfowl. Sample study sites throughout Shetland have been selected and standard counting methods derived. These have taken account of factors such as logistics and accessibility, the effects of weather and observer error and of the seasonal and diurnal variations in the numbers of birds.

Changes in seabird and waterfowl numbers between 1975–79 have been observed. These, with the exception of the bird mortality following the Esso Bernicia oil spill, have been attributed to natural variation. From the scale and local differences between these as yet short-term observations, estimates are presented of the minimum percentage change required in either numbers of birds or their nests before such natural variation is exceeded.

The problems of interpreting changes in numbers are discussed.

The number of dead birds picked up in Sullom Voe after the Esso Bernicia spill corresponded closely to that estimated from the monitoring counts before and after the incident.

From direct sampling, the deeper Rockall Trough and Faeroe-Shetland Channel are known to have a Tertiary-Quaternary sedimentary sequence up to 3000 m thick, which is in places, particularly in the north, underlain by early Tertiary basaltic volcanic rocks. The seamounts in the Rockall Trough are of basic volcanics of probable Upper Cretaceous age. The eastern shelf areas have a rifted basement of Precambrian-Devonian (-?Carboniferous) age, overlain by Permian + Mesozoic sedimentary rocks that reach 5000 m in thickness in rift basins. Tertiary sediments thicken rapidly from the shelf into deep water. The western shelf areas have extensive early Tertiary basalts from the Faeroe Islands to the southern part of Rockall Bank. A thin Tertiary—Quaternary cover exists and Precambrian basement lies beneath.

The pre-Tertiary geology of the deep water areas and the overall crustal structure have been inferred from geophysical investigations. In the Rockall Trough the crust is of oceanic thickness, about 6 km, but it is probably slightly thicker beneath the Faeroe-Shetland Channel. This fact, coupled with the size of the channel compared with other small ocean basins and the knowledge that fully developed oceanic crust exists just outside the mouth of the Rockall Trough, strongly suggests that at least parts of the deep water areas are floored by oceanic crust. However, seismic reflection and magnetic anomaly profiles do not yield observations characteristic of normal oceanic crust.

The age of any oceanic crust in the Rockall Trough and Faeroe-Shetland Channel is equivocal. Between 54° and 59° N a succession of largely sedimentary rocks up to 3000 m in thickness occurs between the Tertiary and the acoustic basement. To the north this succession is masked on seismic profiles by early Tertiary basalts but it is probably present; to the south it is interrupted by a series of acoustically opaque basement ridges. With slow sedimentation rates, this succession could extend back to the late Palaeozoic, but with rapid rates, only to the mid-Upper Cretaceous. An age of mid-Lower to mid-Upper Cretaceous for oceanic crust, equal to that of the ocean crust outside the mouth of the Rockall Trough, is accepted here. Although rapid subsidence and infill in Upper Cretaceous time is not characteristic of major shelf basins around Britain, it may be acceptable for the Rockall Trough and Faeroe-Shetland Channel if they are underlain by oceanic crust rather than continental crust.

A likely model for the formation of the Rockall Trough and Faeroe-Shetland Channel is of continental rifting and subsidence from late Palaeozoic or earliest Mesozoic to mid-Cretaceous time, then sea-floor spreading in Albian (c.105My)–Santonian (c.85 My) time, accompanied and immediately followed by rapid subsidence and deposition. The Tertiary was heralded by widespread basaltic igneous activity which briefly arrested subsidence, but was largely a period of subsidence without sedimentation keeping pace.

An account is given of the species Psilophyton robustius and the relevant literature is reviewed. There follows an illustrated description of a relatively well-preserved fertile, branched specimen. The morphological features of this specimen are discussed with reference to the earlier descriptions by Dawson and others. It has been found necessary to institute a new genus as Psilophyton is now apparently inappropriate for this species. The name given to this new genus is Trimerophyton, which includes the one species Trimerophyton robustius (Dawson) Hopping.