The development of the hypophysis cerebri throughout the Vertebrates has attracted the attention of many workers, and our knowledge of its development and adult structure is comprehensive in many forms of the Reptilia, Amphibia, Fishes, in certain Marsupials, and in several of the best-known Mammals.

Its development in man has recently been investigated by Rudel (1) and by Hochstetter (12), but the small number of specimens as yet examined and described by these and other writers makes it desirable that further work should be done on this subject.

The recent important work of Farmer and Digby (1910) on the cytology of certain varietal and hybrid ferns has raised again the interesting and absorbing question of the mechanism of mitosis. This paper constitutes a valuable addition to the literature which has bulked so largely during the last few years, and which has been instrumental in establishing many interesting and important facts regarding the greatest of all cytological problems—namely, nuclear division. The interest of this later contribution lies, not so much in the actual observations which these writers have jointly recorded—although the facts revealed are important in that they confirm the work of other writers and extend the range of observation,—but rather in the theory which they have deduced from their results and which they have put forward to account for the factors at work in the living cell,—factors which they believe to be concerned in the formation of the achromatic spindle.

The writer recently undertook an investigation of certain aspects of the water relationships in the gametophyte of Polytrichum (2), showing that a large quantity of water ascends through the central strand of the stem and is given off in transpiration from the leafy shoot. The experiments were later extended to the sporophyte, the transpiration rate again being measured (3). While these observations were in progress, it was suggested that it would be useful at the same time to examine in detail the structure of the absorbing organ of the sporophyte, usually referred to as the “foot,” an organ which has been defined by Hy (16) as that part of the seta which is embedded throughout its life in the tissues of the gametophyte.

Dionidid and raphiophorid trilobites are described from the middle Ordovician (Viruan Series) of Jämtland, central Sweden. The family Dionididae is represented by one genus, Dionide Barrande, 1847, and the family Raphiophoridae by five genera, Ampyx Dalman, 1827, Ampyxella Dean, 1960, Ampyxoides Whittington, 1965, Cnemidopyge Whittard, 1955 and Lonchodomas Angelin, 1854. Seven species are described and discussed. Three of these are new: Dionide jemtlandica sp. nov., Ampyxoides minor sp. nov. and Lonchodomas striolatus sp. nov.. The majority of the trilobites described are from the Andersön Shale, equivalent to the H. teretiusculus, N. gracilis and lowermost D. multidens Zones (upper Llanvirn and lower Caradoc), and the Örån Shale, equivalent to the lower D. dingani and the uppermost D. multidens Zones (middle Caradoc). Meraspid and early holaspid material of D. jemtlandica is described.

Whilst the specimens of Bothrodendron mundum Williamson sp. in the Kidston Collection of fossil plant slides in the Glasgow University Botany Department were being examined, certain structural characters were observed which have not been mentioned in previous descriptions of this species. These characters appear to be of sufficient importance to justify the present description, and at the same time it may be noted that photographic illustrations of the aerial stem of this species have not, so far as is known, been previously published.

The new species here described were found in the course of the work of the Lake Survey on Loch Ness and other Highland Lochs. Half of the number were found in lakes, though they are not exclusively lacustrine, three in ponds, two from moss growing on the shores of Loch Ness, and one in a stream running into Loch Ness.

Two new broad-cupped camerate crinoids are reported from the Upper Ordovician (Ashgill, Rawtheyan) Lady Burn Starfish Beds of the Girvan district, Strathclyde, SW Scotland. These represent a significant addition to the limited crinoid diversity known from the Ordovician of the British Isles. The 20-armed diplobathrid Eodimerocrinites littlewoodi gen. et sp. nov. is similar to Silurian Dimerocrinites Phillips, but lacks median ray ridges and has a distinct calyx sculpture. Camerate sp. indet. differs from E. littlewoodi in the sculpture of the dorsal cup and the arrangement of the interbrachial plates, but it preserves insufficient information for it to be further classified with confidence.

New specimens of the diplobathrid gen. et sp. nov. cf Botting from the Middle Ordovician (Llanvirn, Abereiddian) of central Wales, that illustrate hitherto unknown morphological features, including a distal rhizoidal holdfast and a geniculate proximal column, suggest that this species was a rheophilic filter feeder. One specimen is one of the most complete fossil crinoids known from the Ordovician of the British Isles.

The Late Triassic fauna of the Lossiemouth Sandstone Formation (LSF) from the Elgin area, Scotland, has been pivotal in expanding our understanding of Triassic terrestrial tetrapods. Frustratingly, due to their odd preservation, interpretations of the Elgin Triassic specimens have relied on destructive moulding techniques, which only provide incomplete, and potentially distorted, information. Here, we show that micro-computed tomography (μCT) could revitalise the study of this important assemblage. We describe a long-neglected specimen that was originally identified as a pseudosuchian archosaur, Ornithosuchus woodwardi. μCT scans revealed dozens of bones belonging to at least two taxa: a small-bodied pseudosuchian and a specimen of the procolophonid Leptopleuron lacertinum. The pseudosuchian skeleton possesses a combination of characters that are unique to the clade Erpetosuchidae. As a basis for investigating the phylogenetic relationships of this new specimen, we reviewed the anatomy, taxonomy and systematics of other erpetosuchid specimens from the LSF (all previously referred to Erpetosuchus). Unfortunately, due to the differing representation of the skeleton in the available Erpetosuchus specimens, we cannot determine whether the erpetosuchid specimen we describe here belongs to Erpetosuchus granti (to which we show it is closely related) or if it represents a distinct new taxon. Nevertheless, our results shed light on rarely preserved details of erpetosuchid anatomy. Finally, the unanticipated new information extracted from both previously studied and neglected specimens suggests that fossil remains may be much more widely distributed in the Elgin quarries than previously recognised, and that the richness of the LSF might have been underestimated.

In view of the differences observed in the pharmacological action of tetra-methyl- and tetra-ethyl-ammonium chlorides, it seemed of interest to investigate the actions of the methyl-ethyl-ammonium compounds. The chlorides of these compounds—namely, tri-methyl-ethyl-ammonium chloride, di-methyl-di-ethyl-ammonium chloride, methyl-tri-ethyl-ammonium chloride—were kindly prepared for me by Dr J. E. Mackenzie, who has published the mode of preparation and the analysis of them.

The only references I have found to the pharmacological action of the members of this series are brief statements by Tappeiner and Boehm. Tappeiner says that tri-ethyl-methyl-ammonium chloride, unlike tetra-methyl-ammonium chloride, does not produce temporary paralysis of the respiration; Boehm that tri-methyl-ethyl-ammonium chloride, like tetra-methyl-ammonium chloride, causes contracture of an isolated frog's muscle when a solution is applied to it.

The first ichthyosaurian specimens discovered from the Upper Triassic of the Russian Arctic (Kotelny Island, New Siberian Islands) are described herein. They include the remains of large- to small-bodied ichthyosaurians originating from six stratigraphic levels spanning the lower Carnian to middle Norian. The material is mostly represented by isolated vertebrae and ribs, which are not possible to accurately diagnose, but also includes specimens comprising associated vertebrae and a fragmentary skeleton that preserves cranial remains (parabasisphenoid, fragmentary quadrate, partial mandible and hyoids). Based on vertebral and rib morphology, we identify the specimens as representatives of the following taxonomic groups: large-bodied shastasaurids, medium-sized indeterminate ichthyosaurians with a single rib facet in the presacral centra, and small euichthyosaurians with double rib facets present throughout the presacral vertebrae that likely represent toretocnemids and/or basal parvipelvians. In addition, the cranial and mandibular remains preserved in one of the specimens, ZIN PH 5/250, were studied using micro-computed tomography. Its mandible is highly similar to that of toretocnemids, whereas the parabasisphenoid demonstrates a peculiar combination of both plesiomorphic and derived character states, providing the first detailed data on this cranial element in a Late Triassic ichthyosaurian. Furthermore, the specimen also demonstrates a distinctive condition of rib articulation in the anteriormost presacral (cervical) vertebrae, which together with other features allows for the erection of a new taxon – Auroroborealia incognita gen. et sp. nov. Although the phylogenetic position of this taxon is uncertain due to its fragmentary nature, its anatomy, indicating toretocnemid or parvipelvian affinities, further supports the previously hypothesised sister-group relationships between these two clades. The morphology of the parabasisphenoid and vertebral column of the new taxon is discussed in broader contexts of the patterns of evolution of these skeletal regions in ichthyosaurs.

Since reading this paper, I have seen Sir Benjamin Brodie's paper on “The Calculus of Chemical Operations,” read before the Royal Society of London.

The two papers resemble one another, merely in being applications of mathematical language to chemistry. They entirely differ in method, object, and result.

I may here mention, what I have omitted to state explicitly in the paper, that I have no idea of attempting to substitute a functional notation for that in common use. I only propose to use a functional notation to express certain general and serial relations in those cases where the common atomic notation is inconvenient or obscure.

The papers on the Geology of Benguella published in the Transactions (vol. li, part iii, No. 13, 1916, pp. 495–536) had to be issued without the report on the Cephalopods, an omission the more disappointing as they formed the largest and most instructive part of the Cretaceous collection.

In spite of its remote situation, the Old Red Sandstone of Shetland attracted a considerable amount of attention from geologists during the last century. It is exposed in excellent coast sections, which often yield very beautiful cliff scenery; and, in addition to being the most northerly of the stratified rocks of Great Britain, it includes a rich succession of volcanic and intrusive rocks which are of great interest and variety. The axis or backbone of the Shetland archipelago consists of gneiss, mica schist, slate, and limestone, with epidiorites, serpentine, and talc schists. On each side of this there is an area of Old Red Sandstone; that on the east extending from Sumburgh Head, in the extreme south, to Rovey Head, a little north of Lerwick, and comprising also the islands of Bressay, Noss, and Mousa. On the west side of Shetland the Old Red Sandstone Series is much altered, probably by the heat of the granite and other intrusive rocks, so that they often have the appearance of quartzite, and were for a long time regarded as belonging to the metamorphic series. In 1879, however, Peach and Horne (28) showed that, in places, they contained fossil plants which indicated that they belonged to the Old Red Sandstone formation.

Though little is known of the graptoloid reproductive mechanism, graptolites with putatively sac-like appendages, supposedly ovarian vesicles, have been known from the Moffat Shales Group, Southern Uplands, Scotland, for over 150 years. Locally, these co-occur with isolated, two-dimensional, discoidal or ovato-triangular fossils. In the 1870s, Nicholson interpreted these isolated fossils as being graptoloid ‘egg-sacs’ detached from their parent and existing as free-swimming bodies. He assigned them to his genus Dawsonia, though the name was pre-occupied by a trilobite, and named four species: D. campanulata, D. acuminata, D. rotunda and D. tenuistriata. A reassessment of Nicholson’s type material from the Silurian of Moffatdale, Scotland, and from the Ordovician Lévis Formation of Quebec, Canada, shows that Dawsonia Nicholson comprises the inarticulate brachiopods Acrosaccus? rotundus, Paterula? tenuistriata and Discotreta cf. levisensis, the tail-piece of the crustacean Caryocaris acuminata and the problematic fossil D. campanulata. Though D. campanulata resembles sac-like graptolite appendages, morphometric analysis reveals the similarity to be superficial and the systematic position of this taxon remains uncertain. There is no definite evidence of either D. campanulata or sac-like graptoloid appendages having had a reproductive function.

Criticisms by Kriwet regarding recent work on pycnodont phylogeny are based on the use of additive characters. Therefore, applying transformation series in phylogenetic reconstruction is justified in theory and in practice, and an example of additional ontogenetic evidence supporting character ordering in pycnodonts is provided. Moreover, comments on some pycnodont genera are included, and the accurate taxonomic use of the genera Coelodus and Ocloedus is emphasised.

Neuropteris plicata was described by Sternberg in 1826, from a specimen from Mireschau, Bohemia, but the species seems to be very rare and imperfectly known. As other ferns have been identified as N. plicata in error, I give a figure of what I believe to be Sternberg's plant, an identification with which my friend M. Zeiller entirely agrees.

I also figure and describe a new species of Neuropteris, which is identical with that identified as N. plicata by Roehl, but from which species it is essentially distinct.

(1.) The inquiry which, with its results, I propose to lay before the Society, was suggested by the following passage in the very popular Treatise on Logic by Dr Whately, now Archbishop of Dublin.

“As in the case of two probable premises, the conclusion is not established except upon the supposition of their being both true, so in the case of two (and the like holds good with any number) distinct and independent indications of the truth of some proposition, unless both of them fail, the proposition must be true: we therefore multiply together the fractions indicating the probability of the failure of each—the chances against it—and the result being the total chances against the establishment of the conclusion by these arguments, this fraction being deducted from unity, the remainder gives the probability for it.

Nine species of Echinoidea were described by De Loriol From Benguella and mainly from the neighbourhood of Dombe Grande.

1. One of his species, Epiaster catumbellensis, is common in the Lobito district. It is recorded by Be Loriol from the Inflata beds at Catumbella, and the younger Cyprina ivensi sandstone at Dombe Grande. It is a variable species. According to the dimensions given by De Loriol, the length varies from 25 to 36 mm., and the breadth varies from 88 to 94 per cent, of the length and the height from 66 to 77 per cent, of the length. His illustrations show that the species has two chief forms: in one the shape is depressed and the posterior margin is nearly vertical; in the other the posterior interambulacrum is subcarinate, and the posterior margin is more sloping owing to the projection of the lower posterior corner. In De Loriol's figure, pl. viii, No. 4, the posterior margin has a slope of only 7° from the vertical; in his fig. 5 this slope is 15° from the vertical.

Our climate future depends on the delicate, fine balance of earth processes first elaborated on by James Croll, born 200 years ago in 1821. A childhood victim of the Scottish clearances, Croll, after following various indifferent occupations, managed to remove to the then rapidly industrialising city of Glasgow and eventually to Scotland's capital, Edinburgh. He blossomed as a most original, outside-the-box, thinker of great intellectual strength and modesty. He carried out scores of studies across a broad range of research topics, many related to the physical causes of climate change. He is well known for his astronomical theory of the ice ages, but should be much better regarded for his incisive physical insights into the central importance of feedbacks in the Earth system. Although humble, Croll was an ardent controversialist who strongly, perhaps over-strongly, always defended his corner. As well as his many accomplishments as a man of science, Croll was committed to exploring philosophical questions of theism and determinism, topics which occupied his earliest and last publications. A ‘top ten’ selection out of the varied subject areas that Croll tackled are explored herein, along with a brisk survey of their legacy to contemporary modelling studies and to Earth's climate future: (1) causes of climate change (1864); (2) ice-cap melt and sea-level rise (1865); (3) predicting future climates using eccentricity (1866); (4) combining orbital precession, eccentricity and obliquity (1867); (5) geological time and the date of the glacial epochs (1868); (6) geological time and denudation rates (1868); (7) ocean currents and the hemispherical temperature difference (1869); (8) feedbacks – a remarkable circumstance which led to changes of climate (1875); (9) temperature of space and its bearing on terrestrial physics (1880); (10) the causes of mild polar climates (1884).

Electron backscatter diffraction (EBSD) is used to determine the detailed crystallographic orientation of calcite crystals of craniid brachiopods in the context of shell ultrastructure. Sections of shells of two Recent species, Novocrania anomala and Novocrania huttoni, are analysed to provide 3D crystallographic patterns at high spatial resolution. The c-axis of semi-nacre calcite crystals is oriented parallel to the laminae that define the ultrastructure of the secondary layer. This orientation differs from that of rhynchonelliform calcitic brachiopods where the c-axis is perpendicular to the length of morphological fibres and to the shell exterior.