Various selective agents exert their influence on the processes governing the survival of new forms within an established plant group. As the balance of these agents changes so also will the genetic composition of the plant group change. Environmental conditions undoubtedly permit and direct evolution, but apparently the action of the environment is mainly selective in nature, and, although not directly concerned in the production of new growthforms, it aids the survival of suitable forms by establishing a certain amount of genotype isolation. Amongst the various selective agents whose action is confined to the direct selection of genotypes, or phenotypes and therefore indirectly of genotypes, there is the important question of pollination and fertilisation. As the very existence of individuals depends on compatible fertilisation, the investigation of the problem of pollination and fertilisation obtaining within a plant group is essential preparatory to any study of the survival of individuals within that plant group.

Cretaceous and Cainozoic granites and rhyolites in the northwestern U.S.A. provide a record of silicic magmatism related to diverse tectonic settings and large-scale variations in crustal structure. The Late Cretaceous Idaho Batholith is a tonalitic to granitic Cordilleran batholith that was produced during plate convergence. Rocks of the batholith tend to be sodic (Na2O > K2O), with fractionated HREE, negligible Eu anomalies, and high Sr contents, suggesting their generation from relatively mafic sources at a depth sufficient to stabilise garnet. In contrast, Neogene rhyolites of the Snake River Plain, which erupted in an extensional environment, are potassic (K2O > Na2O), with unfractionated HREE patterns, negative Eu anomalies, and low Sr contents, suggesting a shallower, more feldspathic source with abundant plagioclase. Eocene age volcanic and plutonic rocks have compositions transi- tional between those of the Cretaceous batholith and the Neogene rhyolites. These data are consistent with a progressively shallowing locus of silicic magma generation as the tectonic regime changed from convergence to extension.

This communication deals with the fossil plants of the Calciferous Sandstone Series and Carboniferous Limestone Series of Eskdale and Liddesdale; of the Lower Coal Pleasures of Canonbie; of the Middle Coal Measures of Byre Burn, Canonbie; and of the Upper Coal Measures, Joekie's Syke, Cumberland; to which is added a list of the fossil plants of the Calciferous Sandstone Series of Cumberland and Northumberland, with the object of comparing them with those from the corresponding series in Scotland.

Permineralised material of Rhacopteris lindseaeformis (Bunbury) Kidston and Spathulopteris obovata (Lindley & Hutton) Kidston, showing both external morphology and excellent anatomical preservation, is described from the Lower Carboniferous (?Asbian, Upper Viséan) tuffs and dolomitic ashes outcropping at Weaklaw–Gullane, East Lothian, Scotland. These specimens provide the first anatomical information on these two well-known plant compression genera. The rachises have Lyginorachis-type anatomy with distinctive characters in the two species. Spathulopteris rachises correspond to Lyginorachis kingswoodense Meyer-Berthaud, previously described from the localities of Kingswood and East Kirkton, whereas Rhacopteris shows similarities with the petiole attributed to Bilignea from Oxroad Bay. Both foliage types conform to seed-fern frond organisation. This new evidence contradicts previous interpretations of Rhacopteris as a fern or a progymnosperm. We suggest that Rhacopteris lindseaeformis and Spathulopteris obovata represent the foliage of some of the arborescent gymnosperms which are found associated in several contemporaneous localities.

This paper reviews the evidence for environmental change during the Lateglacial period (c.14.7–11.7 ka), perhaps the most intensively studied episode in the Quaternary history of Scotland. It considers first the stratigraphic subdivision and nomenclature of the Lateglacial, before proceeding to a discussion of the various lines of proxy evidence that have been used to reconstruct the spatial and temporal patterns of environmental change during this time period. These include pollen and plant macrofossil data; coleopteran and chironomid records; diatom data; stable isotope and geochemical records; and evidence for human activity. The paper then considers the principal methods that have been employed to date and correlate Lateglacial events: radiocarbon dating; surface exposure dating; varve chronology; and tephrochronology. This is followed by an examination of the constraints imposed on environmental reconstructions, an account of the ways in which the evidence can be employed in the development of an event stratigraphy for the Lateglacial in Scotland, and a proposal for a provisional Lateglacial type sequence (stratotype) at Whitrig Bog in SE Scotland. Emphasis is placed throughout on the potential linkages between the Scottish records and the isotopic signal in the Greenland ice cores, which forms the stratigraphic template for the N Atlantic region. The paper concludes with a discussion of the strategies and approaches that should underpin future research programmes on Lateglacial environmental change in Scotland.

Sparassodonta is a diverse group of extinct metatherian predators that include forms with diets ranging from omnivores to hypercarnivores, including potential bone-crushers and sabre-tooth specialised species. Most of the previous dietary studies on the group were based on qualitative approaches or dental morphometric indexes and/or bite force estimations. In this study, we explore the evolution of mandible shape and diet of Sparassodonta in a comparative phylogenetic framework, using geometric morphometric tools and allometric and discriminant analyses. We analysed the mandible shape of 142 extant species of marsupials and placental carnivores, and 15 fossil sparassodont species. We found that the relationship between shape and size of the mandible is strongly structured by phylogeny, where the more derived borhyaenoids tend to possess stronger and larger mandibles. Derived borhyaenoid sparassodonts and basal borhyaenoids were classified as hypercarnivores (with short and robust mandibular body). Hathliacynid were classified as mesocarnivores or as hypercarnivores, but with lower probabilities and less specialised morphologies (with a long and slender mandible). Although dental morphology suggests that most of the species of Sparassodonta would have been hypercarnivores, the robustness of the mandible seems to be informative regarding the prey size and degree of specialisation. The relationship between mandibular size and shape, and talonid/trigonid relative size, is strongly influenced by the phylogenetic legacy, suggesting that ecological factors could have influenced the evolution of the sparassodonts.

Dear Sir,

Having, as you know, bestowed a good deal of time and attention on the study of that part of physical astronomy which relates to the mutual disturbances of the planets, I have, naturally, been led to consider the various methods of resolving the formula (a2 + b2 − 2ab cos θ)2 into infinite series of the form A + B cos θ + C cos 2θ + &c. In the course of these investigations, a series for the rectification of the ellipsis occurred to me, remarkable for its simplicity, as well as its rapid convergency. As I believe it to be new, I send it you, inclosed, together with some remarks on the evolution of the formula just mentioned, which, if you think proper, you may submit to the consideration of the Royal Society.

The Tertiary geology of north-western India is of particular interest on account of the extensive development of richly fossiliferous rocks of Lower Eocene (including Palæocene) age. The monographs by Cossmann and Pissarro (1909a, 1927) and Vredenburg (1928) have familiarised us with the well-preserved molluscan fauna of the Upper Ranikot beds (Palæocene) of Sind, while Lt.-Col. L. M. Davies' collection of mollusca from a slightly lower horizon in the Samana Range, on the North-West Frontier, has recently been described by myself (1930). With the exception, however, of one family, the Gisortiidæ, dealt with by Vredenburg (1927) and Schilder (1930), the mollusea of the overlying Laki group (Ypresian), as well as of the Khirthar group (Middle Eocene), have been neglected by modern workers. The well-known monograph by D'Archiac and Haime (1853–54), moreover, in which some Laki species are described, has always been a source of confusion owing to the fact that fossils from all horizons from the Danian to the Miocene are grouped together as “Nummulitic,” and no reliable information as to their respective horizons has been available.

Some time ago the author published the results of a series of experiments on the flow of water through tubes having uniformly diverging boundaries, in which the loss of energy corresponding to given angles of conicity of the tubes was determined. These pipes, some circular, others square or rectangular in cross section, had the same initial and the same final areas, these being respectively the same as those of circles of 1·5 inch and 3·0 inches diameter, the ratio of initial to final mean velocity of flow being in each case 4 to 1.

That the facts which I communicate regarding the natural history of the salmon in its earlier stages, may not appear altogether undeserving of consideration, I may premise that my remarks have not proceeded from hasty or imperfect observation, but from the experience of many years sedulously devoted to the subject, the whole of my life, with the exception of a few seasons, having been spent on the banks of streams where salmon are in the habit of depositing their spawn, and where of course the parr is likewise abundant. My opportunities of observation have thus been as ample, as my efforts have been unremitting and laborious, to discover the true history of this invaluable species. I shall here present a brief abstract of my earlier proceedings in relation to the subject.

Articular surfaces reflect the relative movements between adjacent bones, and the ones involved in the elbow joint provide information about forelimb movements and may be useful for making inferences about the substrate use. The proximal articular surface of the ulna was examined through 3-D geometric morphometrics, in order to assess its usefulness as a proxy for paleoecological interpretations; particularly for two small mammals from the early Miocene of Patagonia. The sample was composed of 22 extant small mammals (rodents, carnivorans and primates) and two extinct typotheres: Hegetotherium mirabile (Hegetotheriidae) and Interatherium robustum (Interatheriidae). Forty-five landmarks were taken and principal component analysis (PCA) was used to explore the morphospace structure. The results of PCA for the whole surface were inconclusive; therefore, successive analyses were made, subdividing the surface into sub-units. The PCA for the proximal part of the trochlear notch was the most informative, allowing the recognition of morphospaces with functional value: one for digging rodents and another for most climbers. Neither typothere would have had a specialisation for climbing or digging in the features analysed. This study allows morphological patterns on different parts of a joint to be detected; interpreted, at least partially, as differential responses to different kinds of mechanical stress.

The ammonites dealt with in this paper belong to the family Echioceratidæ (Buckman, T.A., 1913), a varied group of slender, generally evolute forms, usually ornamented by ribs but very rarely tuberculate. In many members of the family the periphery has only a feeble keel, but in some a sharp keel, with or without sulci, may be present.

Ammonites of this family have most frequently been recorded as Ammonites raricostatus, and the raricostate species are by far the best known. The species at present classified with the Echioceratidæ, however, can be roughly grouped, with reference to their form only, as follows :—

1. Raricostate forms, with strong widely spaced ribs and feeble carina, e.g. A. raricostatoides, A. zieteni.

2. Forms with closely spaced ribs, with carina absent or feeble, e.g. A. viticola, A. prorsum.

3. Forms with elevated whorls, bearing regular ribs of moderate strength and with carina and sulci, e.g. A. aplanatum.

4. Forms becoming smooth on the last whorls, which are thin, with an acute keel and obsolescent sulci, e.g. A. macdonnellii.

The occurrence of Monograptus in the Carmichael Burn section of the Midland Valley of Scotland has now been confirmed. A new fauna is described from beds previously regarded as Ludlovian which are here suggested to be of Valentian age. A detailed stratigraphical succession has been established and the structure of the area revised in the light of this new information, most of which was derived from a number of exploratory pits sunk for the purpose. Tentative correlations with the other Midland Valley inliers are attempted and many problems requiring future solution are raised.

The Kilmaluag Formation on the Isle of Skye, Scotland, provides one of the richest Mesozoic vertebrate fossil assemblages in the UK, and is among the richest globally for Middle Jurassic tetrapods. Since its discovery in 1971, this assemblage has predominantly yielded small-bodied tetrapods, including salamanders, choristoderes, lepidosaurs, turtles, crocodylomorphs, pterosaurs, dinosaurs, non-mammalian cynodonts and mammals, alongside abundant fish and invertebrates. It is protected as a Site of Special Scientific Interest and by Nature Conservancy Order. Unlike contemporaneous localities from England, this assemblage yields associated partial skeletons, providing unprecedented new data. We present a comprehensive updated overview of the Kilmaluag Formation, including its geology and the fossil collections made to date, with evidence of several species occurrences presented here for the first time. We place the vertebrate faunal assemblage in an international context through comparisons with relevant contemporaneous localities from the UK, Europe, Africa, Asia and the US. This wealth of material reveals the Kilmaluag Formation as a vertebrate fossil assemblage of global significance, both in terms of understanding Middle Jurassic faunal composition and the completeness of specimens, with implications for the early evolutionary histories of mammals, squamates and amphibians.

An excavation in the mid-Ordovician (Caradoc) Bardahessiagh Formation at Pomeroy, Co. Tyrone, Northern Ireland in 1992 has yielded a rich fauna of invertebrates, including several specimens of the scleractiniamorph coral Kilbuchophyllia. The material is assigned to the species K. clarksoni, previously described from penecontemporaneous levels in the Kirkcolm Formation of the Northern Belt of the Southern Uplands. The diagnosis of K. clarksoni is extended to include specimens of significantly greater size than the Southern Uplands material. All the material is mouldic but includes composite moulds, which in comparison with the preservation of other faunal elements, strongly suggests an original aragonitic composition for the kilbuchophyllid skeleton. Furthermore, details of insertion of higher cycles of septa visible on one particularly well preserved specimen confirm the process of septal substitution in these corals. Septal substitution is otherwise unique to post-Palaeozoic scleractinian corals and indicates the presence of paired mesenteries in the kilbuchophyllid polyp. The significance of this for the evolution of these corals and related anemones is discussed. The discovery of kilbuchophyllid corals at Pomeroy supports the view that post-Caradoc sinistral strike-slip movement on the Southern Uplands Fault was unlikely to have exceeded 200 km.

A revision of the Lower Devonian dalmanitid trilobites of the Prague Basin (Czech Republic) is presented. The subfamily Odontochilinae Šnajdr is considered a synonym of Dalmanitidae Vogdes. Twenty-one previously and five newly described (three in open nomenclature) species and subspecies occur in the Prague Basin from the lowermost Pragian (one problematic specimen possibly comes from the uppermost Lochkovian) to the Lower Emsian; the last questionable record is from the Upper Emsian. The species have been assigned to four genera and subgenera: Odontochile Hawle & Corda, Reussiana Šnajdr, Zlichovaspis (Zlichovaspis) Přibyl & Vaněk and Zlichovaspis (Devonodontochile) Šnajdr. These trilobites are considered as scavengers or opportunistic predators, living most of their lives as vagrant benthos burying in the muddy substrate to find organic remains. The first undoubted adult-like meraspid specimens are described.

The stem of the various species of Piper is characterised by its anomalous vascular structure. Medullary bundles are present throughout the genus, and there is, in addition, a modified type of secondary thickening. During an investigation of these features my attention was called by Professor Montagu Drummond to certain endodermal characters which appeared to be of considerable interest and which suggested that a more extended investigation was desirable.

Reference to the literature showed that the few earlier investigators of the genus had concerned themselves mainly with the peculiarities of the vascular system. J. E. Weiss (18) made some general observations on the occurrence of the endodermis in the genus, but no mention of the genus is made in the comprehensive monographs by Kroemer (8) and by Mylius (10) on the endodermis, or in the writings of Van Wisselingh. It would appear therefore that no detailed investigation of the endodermis in the genus has been carried out, in the past.

Barrow describes from Glen Clova an important Older Granite intrusion, the muscovite-biotite-gneiss which he holds responsible for the formation of staurolite, kyanite and sillimanite zones of progressive regional metamorphism in the district. He states that the gneiss was filter-pressed during emplacement so that potash was strained off and concentrated in the south-eastern outcrops of the intrusion leaving its north-western portions enriched in soda. He claims that by the same process the separate intrusive areas comprising the gneiss have often been marginally enriched in potash and pegmatite.

The factual basis of the filter-press hypothesis does not withstand careful re-examination. The individual intrusive areas of muscovite-biotite-gneiss bear no marginal zones of potash and pegmatite enrichment like those envisaged by Barrow. The muscovite-biotite-gneiss in its entirety comprises two distinct units, a heterogeneous group of banded quartz-oligoclase-mica-gneisses that were intensely deformed plastically during high-grade metamorphism, and a later series of non-migmatitic microcline-granite intrusions. In neither unit can any regular variation in potash/soda ratio be detected in passing directly from north-west to south-east.

New data are provided concerning the distribution and mode of occurrence of Barrow's metamorphic zonal index minerals. Sillimanite, as fibrolite, often replaces mica and accompanies kyanite in specimens from many localities.

Bouguer anomaly maps covering most of Ayrshire at a density of about one station per sq. km., show a close relationship between anomalies and the distribution of the Upper Palæozoic rocks in the area south of the Inch-gotrick Fault, but are less clearly interpreted to the north, where thick dense igneous masses are present.

In central and south Ayrshire the gravity field may be largely interpreted in terms of the known density-contrasts at the interfaces separating Upper and Lower Old Red Sandstone, and Lower Old Red Sandstone and Lower Palæozoic rocks. The major structure, the Mauchline Basin, is reflected clearly in the largest anomaly, and there is evidence of a culmination of its south-western limb near Kirkoswald. The important N.E.–S.W. faults also give rise to large anomalies, which may be connected with the known geology. It is inferred that they moved as normal faults in Carboniferous times, and that the adjacent synclines are essentially sags associated with the fault displacements. There is geophysical evidence that both the Southern Upland and Kerse Loch Faults existed in Middle O.R.S. (proto-Armorican) times. It is concluded that a hypothesis of N.–S. Armorican stress is not valid in south Ayrshire.

In north Ayrshire, many of the anomalies are best explained by changes of thickness of the Millstone Grit lavas and of the Clyde Plateau lavas, and by the presence of thick dolerite intrusions. Additional evidence is needed, however, before final conclusions may be drawn.