Lower Cambrian shallow-water carbonates enclosing microbial structures are documented for the first time from the upper Lastours Member of the Montagne Noire (southern France). Microbial organisms constructed self-supported boundstones resulting in the formation of exclusively microbial-accreted buildups, which exhibit three main types of non-skeletal microbialites: planar stratiform stromatolites, dome-shaped stromatolites and nonlaminated (thrombolitic) biostromes. In addition, thrombolitic boundstones display four distinct microbial microstructures: clotted and Renalcis-like forms, branching bushy forms, clusters of unbranching straight filaments and crustose forms.

The upper member of the Lastours Formation records an upward transition from a shalydominant open shelf to a protected shelf environment bounded by a surface representing a major subaerial exposure. Initially, at the inception of the highstand systems tract, flat stratiform stromatolites formed on open sea subtidal shaly substrates, while stacked domal stromatolites developed in peritidal areas which record subaerial exposure. In contrast, prograding shoal barriers of the transgressive systems tract favoured the establishment of thrombolitic boundstones in protected (back-shoal) environments.

Since the report on the Hydroids collected by the Scotia was completed, almost three years ago, I have had an opportunity, thanks to the kindness of Dr W. S. Bruce, of looking through the enormous mass of material brought together by him during his Antarctic voyages. The search, begun in the hope of finding a few minute species—which, since many are epizoic on other forms of marine life, might readily be overlooked on cursory examination—has resulted in the addition of no less than 25 forms to the 36 already recorded. Deducting from this total of 61 forms two varieties, it appears that the Scotia collection contains in all 59 distinct species. Few, indeed, of these have been obtained in truly Antarctic latitudes—subantarctic or temperate seas having furnished the greater number—but this result is in accordance with the findings of the majority of the recent Antarctic expeditions. Dr Billard, in summarising the results of the Belgian, Swedish, and French expeditions, states that the known Hydroid fauna of Antarctic regions comprises only 32 species. But from his list he has, I think unjustly, excluded South Georgian records. His list, moreover, published before the valuable paper by Professor Hickson and Mr Gravely on the Discovery Hydroids was issued, necessarily makes no reference to the large number of forms recorded by them from Victoria Land.

Although the subject of the following communication has of late years attracted a great deal of attention among the public generally, it may, nevertheless, be well for me to preface my statements by a few elementary remarks.

It is well known that organic substances, when left exposed under ordinary circumstances, undergo alterations in their qualities. For example, an infusion of malt experiences the alcoholic fermentation; a basin of paste prepared from wheaten flour becomes mouldy; or, again, a piece of meat putrefies when so treated. The microscope shows that each of these changes is attended by the development of minute organisms. In the fermenting sweet-wort the yeast which falls to the bottom of the containing vessel is found to consist of budding cells, constituting the yeast-plant, Torula Cerevisiæ, represented in Plate XXII. fig 2. In the mouldy paste the blue crust which is the most frequent appearance, owes its colour to the spores of a species of filamentous fungus, Penicillium Glaucum, the commonest of all moulds, of which fig. 1 in Plate XXII. represents a pencil of fructifying threads; and the putrid flesh will be probably found teeming with bodies which, in the most typical form, consist of two little rods, connected endways as by a joint, such as are seen at a, fig. 3, Plate XXII., characterised by astonishing powers of locomotion, and, from their rod-like form, termed Bacteria.

Considerable interest attaches to the unravelling of the complete life-history of the Psilotaceæ, since they are apparently the nearest living representatives of the Sphenophyllales.

The recent description of the gametophyte of Tmesipteris by Prof. Lawson, whose figures 1 had the privilege of seeing before they went to press, and the discovery of the gametophyte of Psilotum, which is the subject of the present paper, form a first contribution to the solution of this problem. It is of some interest to note that there remains now no Pteridophyte the gametophyte of which has not been described.

In the early part of this research I was fortunate in finding a locality near at hand in which Psilotum flourished, and therefore I had at my disposal abundance of spores and later numerous prothalli.

At the time of his death Dr Duerden was contemplating the preparation of a paper of this nature, and it is felt by Mrs Duerden that had he been able to express his wishes in this connection he would appreciate a record of the conclusions made by him. No one realised more than Dr Duerden himself the gaps which are still present in our knowledge and interpretation of the grouping of follicles and fibres in the mammalia, and this work is certainly not meant to be taken as representing Dr Duerden's final view or those of his colleagues at the Wool Industries Research Association. In view of the unique value of much of the material the present notes are intended, therefore, to form a basis and reference, firstly, for workers engaged in the general development of any mammalian coat from a morphogenic and phylogenetic point of view, and secondly, for those interested particularly in factors concerned in the formation of different types of fleeces in sheep. The conception of the follicle bundle as a discrete and basic genetic unit largely determining the initial form of the wool staple is of the highest importance in studies on the inheritance and developmentof fleece characters.

The Mucorales have a wide geographical distribution and for seventy years they have been the subject of investigation both in Europe and in America. In this country, however,little research has been done on this group, the only workers being Bayliss-Elliott (1930) who has investigated the microflora of the Dovey salt marshes, Dale (1912, 1914) who examined the fungus flora of soil at Cambridge, and Brierley (1923, 1927, 1928) who has done considerable work on soil study. Although certain of the Mucorales were isolated by the last named, he was mostly concerned with the general methods of soil culture. The important quantitative technique was devised by Brierley (1927). Oudemans and Koning (1902) were the first to show the presence of Mucors in the soil. They examined the soil fungi in Holland and isolated two new species of Mucors. Möller (1903) investigated the fungi found in Pine mycorrhiza and obtained a further four new species. Hagem (1907, 1910) studied the morphology and physiology of seventeen Mucors from the soil of Norway, seven of which were new species. In 1908 Lendner published his “Les Mucorinées de la Suisse,” an important contribution to the study of this group of fungi. A criticism which might be levelled at this work is that it is difficult to ascertain from it whether or not Lendner used pure cultures on which to base his descriptions. He merely states that “dilution methods used in Bacteriology were employed,” no mention of monospore cultures being made. Further important work on this group has been done by Korpatschewska (1909), Namy-slowski (1906, 1920), Naumov (1914, 1924, 1935), Ling-Young (1930), Johann (1932), Jensen (1912, 1931), and in the Kryptogamenflora der Mark Brandenburg (1935) Zycha gives a complete revision of the classification of the Mucorales. A survey of the geographical distribution of this group of fungi is found in the work of Niethammer (1935), while further classification has been done by Linnemann (1936). In America, Povah (1917) and Waksman(1916, 1917, 1922, 1927) have both added considerably to our knowledge of the Mucorales in the soil.

The causes of compositional diversity in the Tuolumne Batholith, whether source heterogeneity, magma mixing, or fractional crystallisation, is a matter of longstanding debate. This paper presents data from detailed mapping and a microstructural and major element, trace element and isotopic study of an elongate lobe of the Half Dome granodiorite that protrudes from the southern end of the batholith. The lobe is normally zoned from quartz diorite along the outer margin to high-silica leucogranite in the core. Contacts are steep and gradational, except for the central leucogranite contact, which is locally sharp: magmatic fabrics overprint contacts. A striking feature of the lobe is the 18 wt SiO2 range comparable to that observed for the entire Tuolumne Batholith. Feldspar-compatible elements (Sr and Ba) decrease towards the centre, while Rb increases. Light and middle REEs show a smooth decrease towards the centre of the lobe. Calculated initial isotopic ratios of 87Sr/86Sr(i) and εNd(t) have identical values within error across the lobe, except in the central leucogranite, the most silica rich phase, which shows a slightly more crustal signature. Field, structural, geochemical and isotopic data suggest that fractionation was the dominant process causing compositional variation in this lobe. It is envisioned that this fractionation/crystal sorting occurred in a vertically flowing and evolving magma column with the present map pattern representing a cross-section of this column. Thus the areal extent of the lobe represents a minimum size of interconnected melt at the emplacement level of the Tuolumne Batholith and, given its marginal position, limited width and proximity to colder host rocks, implies that fractionation in larger chambers likely occurred in the main Tuolumne Batholith magma chamber(s).

In recent years intensive investigations on the plumage dimorphism characteristically developed in most breeds of domestic fowl have resulted in a great increase in our knowledge concerning the rôle of the endocrine glands, in particular the thyroid and sex organs, in relation to plumage differences. Since, however, the majority of these researches have been directed to the plumage exhibited by the adult bird, it is suggested that an analysis, both observational and experimental, of the earlier plumage phases shown successively from hatching to maturity might yield much valuable data concerning the nature of the hormonic stimuli involved.

In the Proterozoic complex of the Schirmacher region of East Antarctica, a retrograde pressure–temperature (P–T) history has been inferred through quantitative geothermobarometry and fluid inclusion studies of the mafic granulites. Microthermometric investigations of the fluid phases trapped in quartz and garnet identified three types of inclusions, namely, earliest pure CO2 inclusions (0·987–1·057 g cm−3), CO2–H2O inclusions and aqueous inclusions.

The temperature and pressure of metamorphism have been estimated through different calibrations of geothermometers and geobarometers. The mineral reactions and compositional zoning in the minerals record P–T conditions from nearly 837 ± 26°C, 7·1±0·2 kbar to 652 ± 33°C, 5·9 ± 0·3 kbar. A good correlation between the fluid and mineral data is observed. The isochores typical of highdensity CO2 fluids fall well within the P–T box estimated by mineral thermobarometry. The abundance of primary CO2 inclusions in early metamorphic minerals (notably quartz and primary garnet) and the general correspondence between fluid and mineral P–T data indicate a ‘fluid-present’ carbonic regime for the high-grade metamorpism; however, from the present data largescale CO2 advection could not be envisaged. The subsequent stages involved a decrease in CO2 density, a progressive influx of hydrous fluids and the generation of retrograde amphibolite facies metamorphism in the area.

The estimated P–T conditions of the region suggest that the rocks were metamorphosed at a depth of 19–24 km, with a geothermal gradient of c. 3°5C km−1. The estimated P–T conditions of the rocks imply a clockwise P–T–t path with a gradual decrease in temperature of around 250°C and a decrease in pressure of around 1700 bar. They have a dP/dT gradient of ≈7 ± l bar °C−1, arguing for an isobaric cooling history of the terrane under normal thickened crust after the underplating of mantle-derived material.

In the year 1818, my attention was accidentally directed to the subject of water in crystallised bodies, by the explosion of a crystal of Topaz, which I had exposed to a red heat, for the purpose of expelling its colouring matter. This violent disruption of the specimen, which was shivered into a thousand films, of extreme tenuity, arose from the expansion of the imprisoned fluid, and induced me to institute a series of experiments, for the purpose of determining the nature of the fluid, the form of the cavities which contained it, and the arrangement of these cavities in reference to the crystalline form of the mineral.

In 1861, in a part of the province of Otago, New Zealand, not previously botanically explored, I made, among other botanical collections, one of Lichens and Fungi. The number of new species and varieties proved to be considerable, amounting to about 20 per cent. of the whole lichens, and 40 per cent. of the whole fungi, collected. Since my return home, I have submitted (with a view specially to the study of the minute anatomy of the reproductive organs and their contents) the new species (and varieties) in question—some of them repeatedly—to microscopical examination: the results whereof are contained in the notes which follow.

The genus Anaspides was founded in 1894 by Mr G. M. Thomson of Dunedin, New Zealand, for the reception of a very remarkable Schizopod Crustacean which he had discovered in a fresh-water pool at an altitude of 4000 feet on Mount Wellington in Tasmania. The very striking peculiarities of the animal, the absence of a carapace, the presence of plate-like gills attached to the bases of the thoracic legs, and the possession of an auditory organ in the peduncle of the antennules, led its discoverer to regard it as the type of a new family of Schizopods, the Anaspidæ, while suggesting that it might be entitled to “even higher specific rank.” I have had an opportunity of examining three specimens of Anaspides presented to the Museum of University College, Dundee, by Dr Chas. Chilton of New Zealand, and from the dissection of one of these I have been able to supplement, in some important points, Mr Thomson's account of the external anatomy of the animal. I wish also to call attention to the remarkable resemblance, indicative I believe of close affinity, which Anaspides bears to certain Palaeozoic Crustacea belonging to a group hitherto supposed to be unrepresented among living forms. The present paper has been prepared under the direction of Prof. D'Arcy W. Thompson.

Well-preserved compression material of Zosterophyllum myretonianum Penhallow from the Lower Old Eed Sandstone in Angus has yielded additional information about the structure of this plant, one of the earliest known types of vascular land plants. It is the earliest plant in which the structure of the epidermal cuticle, stomata and complete tracheids has been clearly demonstrated. The basal regions of the plant are found to consist of branching axes some with arrested or dormant side branches. Simple dichotomy into two equal and similarly orientated branches is rare. H-type branching and some modifications of it are of frequent occurrence in the basal region of the plant. Parts of this region of the plant have no stomata although a cuticle was present. The upright fertile axes rarely branched.

Harmaline is one of two alkaloids found in the seeds of Peganum Harmala, a strong-smelling herbaceous plant belonging to the order of Rutaceæ. This plant grows to a height of from 1 to 3 feet, is much branched, and profusely covered with leaves. It is found wild in S. Europe, Asia Minor, Egypt, Arabia, N.W. India, and Siberia. It is the Πήγανον ἄγριον (wild rue) of Dioscorides, Πήγανον being the name still applied in Greece to several species of Ruta.

Lepidodendron calamopsoides sp. nov. is described from petrified protostelic stems formerly considered identical with Levicaulis arranensis Beck. The stems range from 2 to 20 mm. diameter and some possess leaf-cushions usually about 10 × 1 mm.

Three specimens are known showing the transition from stem to rooting organs. Secondary xylem has only been seen in the transition region and rooting organs. The latter resemble Calamopsis dubia Solms-Laubach now considered to be part of the closely related Lepidodendron saalfeldense.

Plesiosiro madeleyi Pocock, 1911, the monotypic representative of the fossil order Haptopoda Pocock, 1911 from the British Middle Coal Measures (Upper Carboniferous, Westphalian B) of Coseley, Staffordshire, is redescribed. A specimen from Sparth Bottoms, Lancashire is not a Plesiosiro and is referred to Arthropoda incertae sedis. Plesiosiro was probably a predator, having tooth-like projections on the femora for prey capture, and shows adaptations of the limbs for crawling in narrow spaces. The uncertain nature of the chelicerae, eyes and respiratory organs makes resolving the phylogenetic position of Plesiosiro difficult, though Haptopoda deserves its status as a separate order. Plesiosiro resembles both cythophthalmid and trogulid opilionids. Its broad prosoma–opisthosoma junction could be interpreted as a synapomorphy for Plesiosiro + Opiliones, but this character is not unique to these orders. Alternatively, Plesiosiro has a large, ventral opisthosomal sclerite. This is interpreted here as a genital operculum, a synapomorphy for Tetrapulmonata, and Plesiosiro is tentatively referred to this clade. Based on the synapomorphies of a divided sternum and subdivided telotarsi a relationship of the form: (Plesiosiro (Amblypygi (Thelyphonida + Schizomida))) is proposed.

The stratigraphy of red bed successions in the Clew Bay area of County Mayo (Ireland) is described, and new palynological evidence for the age of some of the rocks is presented. The Old Red Sandstone in the Clew Bay area comprises several lithostratigraphic units. The Louisburgh succession is interpreted as part of a Silurian marginal marine sequence. Devonian strata are represented by the Islandeady Group which has yielded plant spores which suggest that these rocks should be assigned to the Lower Devonian (Siegenian to Emsian) and the Beltra Group which contains Middle Devonian (Eifelian) spores. These Lower and Middle Devonian strata are probably separated by an unconformity, and are overlain with clear unconformity by the highest unit, the Maam Formation, which is Dinantian (Carboniferous) in age. The Clew Bay Old Red Sandstone succession, therefore, shows important differences from that of the Midland Valley of Scotland, with which it has previously been compared.

The lead isotope compositions of 61 galenas from central and southern Scotland vary markedly between different regions. Most galenas from the southern Grampian Highlands yield isotope ratios (206Pb/204Pb 17·77 ± 0·25, 207Pb/204Pb 15·47 ± 0·05, 208Pb/204Pb 37·63 ± 0·26) less radiogenic than those from Midland Valley galenas (18·22 ± 0·12, 15·55 ± 0·05, 38·13 ± 0·14) whilst galena lead from the Southern Uplands (18·28 ± 0·12, 15·56 ± 0·03, 38·21 ± 0·18) is more radiogenic than that from the southern Midland Valley (18·12 ± 0·06, 15·52 ± 0·02, 38·06 ±0·10). The change in isotopie composition across the Highland Boundary fault reflects the presence or absence of Dalradian rocks which included a magmatic component of lead. Galenas from the Dalradian sequence in Islay, where igneous rocks are lacking, have a composition (18·14±0·04, 15·51±0·01, 37·90±0·02) more like Midland Valley galenas. In the Southern Uplands, galenas yield lead isotope ratios similar to those of feldspars from Caledonian granite (18·30 ± 0·14, 15·57 ± 0·04, 37·96 ± 0·15) analysed by Blaxland et al. (1979). The similar ratios reflect the incorporation of Lower Palaeozoic sedimentary rocks into the granite magma, rather than a granitic source for the mineralisation. The granites were then thermal-structural foci for later mineralising fluids which leached metals from the surrounding rocks. Within the Midland Valley, galenas hosted in Lower Devonian-Lower Carboniferous lavas are notably more radiogenic (18·31 ±0·12, 15·58 ± 0·06, 38·20 ± 0·16) than sediment-hosted galenas (18·14 ± 0·07, 15·52 ± 0·02, 38·08 ± 0·10). The Devonian lavas at least may have inherited lead from subducted (? Lower Palaeozoic) rock incorporated in the primary magma.

The early actinopterygian Mesopoma planti is reassigned to a new genus on the basis of data obtained from high-resolution computed tomography (CT) scans of an unusually well-preserved specimen from the Early Pennsylvanian of Lancashire, UK. The former M. planti is joined by two further Mesopoma species from the Late Mississippian of Scotland. CT scans of the key planti specimen bring to light new details of the dermal skull, pectoral girdle and fin. Among the cranial features, CT data reveal a specialised, anteriorly projecting preopercular bone, the location of the spiracular duct opening, presence of a so-called coronoid process on the lower jaw and the full three-dimensional shape of the snout. Of the pectoral girdle and fin, for the first time in a Palaeozoic actinopterygian it has been possible to complete a three-dimensional reconstruction of the entire endoskeleton in articulation. The fin presents new diversity within a conservative general pattern, revealing for the first time a double propterygium. Girdle shape shows that the fin orientation is derived: rotated with the leading edge dorsalmost. These details are used to identify unexploited character states for use in phylogenetic analyses, while functional implications of the fin and girdle suggest advanced locomotory control emerging among different groups of post-Devonian ray-finned fishes.