The first part of this paper was communicated to the Society on June 1, 1896, and published in the Transactions (vol. xxxviii. part iii., No. 20, pp. 681–755), the data there discussed being mean values of the climatic elements for each day in the year.

In the present paper an attempt will be made to focus the results deduced from an examination and reduction of the various meteorological registers kept in Edinburgh from 1731 to 1736 and from 1764 to the present time, with special reference to secular and other weather changes.

The condensed results of a number of minor papers dealing with subjects which have, in many cases, formed part of the daily routine of observation during the last ten years have also been included. Attention may also be called to the list of remarkable atmospheric occurrences, such as phenomenal gales, snow-storms, auroras, etc., which is contained in the appendix. In presenting this paper my warm thanks must be expressed to Dr Buchan, from whom I received invaluable advice when points of difficulty arose in the reduction of the observations.

It is well known that double ovariotomy, when performed prior to puberty, exercises a prejudicial effect not only upon the generative organs but also upon the whole organism. There is, however, some disagreement as to the results of this operation when performed after puberty, and particularly in regard to the occurrence of heat or menstruation.

It is the purpose of this paper to adduce further evidence upon this question, as well as to describe experiments the result of which indicates that the nature of the ovarian influence is chemical rather than nervous.

The late Llandovery (early Silurian) of South China has yielded a locally abundant and diverse microvertebrate fauna. This includes scales of the little-known mongolepids, sinacanthid spines and a whole host of as yet unassigned forms. The material recovered provides a considerable amount of new information about the diversity of fish in the South Yangtze biome during the early Silurian, and suggests that ichthyoliths have a future role to play in Lower Palaeozoic stratigraphic correlation across China and into Mongolia and Siberia. A new family of mongolepids, the Shiqianolepidae, is erected, accommodating the new genus Shiqianolepis with the type species S. hollandi. The description of Shiqianolepis enables the identification of a differentiated squamation in mongolepid fish, a feature which has not previously been recognised. Two further taxa, Rongolepis cosmetica gen. et sp. nov. and Chenolepis asketa gen. et sp. nov., of, as yet, uncertain affinities are also erected.

Although they are thoroughly aquatic animals, the Tardigrada. are not very abundant in permanent waters. They are most thoroughly at home in situations where the supply of moisture is intermittent, and are therefore conspicuous members of that numerous community of animals known as moss-dwellers. They share with the Bdelloid Rotifera the power of withstanding dessication.

Although they have their headquarters in land mosses, many species are quite at home in ponds, rivers, and lakes.

As lacustrine animals they belong entirely to the littoral region, into which they no doubt continually migrate from the adjoining mosses. A favourite habitat is that strip of shore between the highest and lowest levels of the lake, the ‘grève inondable’. of Forel. Into this often mossy margin they may migrate in the ordinary way, when the loch is low. The next step may be involuntary—the loch rises during floods, and the bears, in common with many other animals, find themselves, willy-nilly, converted into lake-dwellers. It appears to be certain that of the water-bears introduced into lakes, by whatever means, some have found the conditions very congenial. Several species have hitherto been found nowhere but in lakes.

The author (1928) of the present communication has already published the results of a field survey of the Lower Old Red Sandstone in Perthshire and Angus, which were linked with those derived by Campbell (1913) from his study of similar and older series of beds in Kincardineshire, to the north-east. For thirty-five miles to the south-west of the R. Tay, no detailed investigation of the sequence or tectonics of the rocks immediately adjacent to the Highland Boundary Fault, separating the Grampians proper from the Central Valley of Scotland, has been undertaken. A comprehensive account of the rocks of this belt in the region around Aberfoyle is available in the paper by Campbell and Jehu (1917).

Structures in and around volcanic necks at Dunbar are interpreted as belonging to two different stages in volcanism. Some, which are related to an early neck emplacement stage, include small ring structures—probably incipient (crypto-volcanic) necks—filled with marginally flow-banded breccias, dykes of similarly margined unbedded tuff, and tuff-penetrated wall rocks. Among the last are sandstones veined along planes of minor fracture by very fine sand.

Other structures belong to a later stage during which bedded tuffs, that had originally accumulated sub-ærially, subsided into the necks in a process here likened to caldera formation. In one large neck the bedding is relatively undisturbed, but in smaller necks there are high inward dips from the margins and collapse structures, sometimes accompanied by reconstitution of the clastics, at the centres. Diagnostic features of subsidence margins are anastomozing veins of carbonate, locally accompanied by hæmatite, and these appear to be related to dykes of flow-banded sandstone and sandy tuff intruded along fractures initiated inside the necks during subsidence. Other structures described are ring-fracture, with or without gouge, and down-drag of wall-rocks: these suggest a solution to the space problem posed by caldera mechanism.

Conodont faunal dynamics and high-resolution biostratigraphy in the lithologically and faunally anomalous ‘Täljsten’ succession, which spans the Darriwilian Lenodus variabilis–Yangtzeplacognathus crassus Zone boundary, were investigated in a 2·5 m-thick section on Mt Kinnekulle that includes an interval yielding fossil meteorites and extraterrestrial chromite. The previous interpretation that this interval reflects a regression is consistent with the occurrence and abundance patterns of some conodont taxa. The disappearance of e.g., Periodon, suggests that the regression began prior to the deposition of the grey ‘Täljsten’. The transition from red to grey limestone coincides with a conspicuous faunal re-arrangement. The lower half of the ‘Täljsten’ reflects a gradual shallowing favourable for some taxa, such as Lenodus, and the immigration of Microzarkodina cf. ozarkodella and Histiodella holodentata. In the middle of the ‘Täljsten’ interval, coinciding with the appearance of abundant cystoids, conditions became less hospitable for conodonts, resulting in a low diversity and low abundance fauna, which occurs to the top of the interval. The overlying red limestone, apparently deposited during a deepening event, marks a return to pre-‘Täljsten’ conditions with a re-organised fauna. The close correlation between the lithologic shifts and conodont faunal changes demonstrates the usefulness of conodonts as environmental indicators.

Four new petrified specimens of cupules assigned to Hydrasperma cf. tenuis Long are described from the Cementstone Group of Oxroad Bay, East Lothian. In one of these specimens four ovules are present. Three of the specimens are interpreted as representing a pair of cupules derived from a single megasporophyll showing dichotomy so that each cupule is termed a hemi-cupule and has two lobed halves which represent quarters of the entire megasporophyll. In the fourth specimen five cupules are present, each possessing two lobed halves not sub-divided into quarters. Hydrasperma is thus interpreted as showing two kinds of cupules designated mega-cupules and paired hemi-cupules. The theory is developed that angiosperm carpels have evolved from the two kinds of pteridosperm cupules.

Fifteen specimens of Eristophyton stems from the Lower Carboniferous Cementstone Group of Berwickshire and East Lothian have been examined. Three possess medullary rays comparable to E. waltonii Lacey, the others have rays like E. beinertianum (Göpp.) Zalessky. In one specimen assigned to E. waltonii a leaf-trace subdivides outside the secondary xylem to form an arc of six separate bundles. Another stem of E. waltonii has attached closely spaced petiole bases one of which is clearly identifiable as Lyginorachis with six vascular bundles arranged in an arc. Stems of Eristophyton from five localities occur associated with petioles or rachises possessing a U-shaped vascular bundle with abaxial ridges like L. waltonii Calder. As these may occur mixed with rachises agreeing with L. brownii Calder the latter is regarded as synonymous. Detached petioles found associated with E. beinertianum may possess four or six basal bundles. The evidence suggests that the U-shaped petiolar bundle passes down into four then six basal bundles and such petioles are associated with both E. waltonii and E. beinertianum. Calder (1935, pl. 1, fig. 2) showed dichotomy in the petiole bundle.

In addition different rachises are known possessing a more massive U-shaped bundle but lacking sclerotic nests and sparganum outer cortex. These are assigned to Cladoxylon edromense sp. nov. Cortical nests occur in both E. waltonii and L. waltonii and may be compared with the sclerotic plates in the compressions of Diplotmema dissectum Brongn. and D. patentissimum Ett.. The evidence supports the view that Eristophyton is a pteridosperm with bifurcate fronds known as L. waltonii Calder when petrified and comparable to Diplotmema when compressed.

The following attempt to investigate the real nature of Symbolical Algebra, as distinguished from the various branches of analysis which come under its dominion, took its rise from certain general considerations, to which I was led in following out the principle of the separation of symbols of operation from those of quantity. I cannot take it on me to say that these views are entirely new, but at least I am not aware that any one has yet exhibited them in the same form. At the same time, they appear to me to be important, as clearing up in a considerable degree the obscurity which still rests on several parts of the elements of symbolical algebra. Mr Peacock is, I believe, the only writer in this country who has attempted to write a system of algebra founded on a consideration of general principles, for the subject is not one which has much attraction for the generality of mathematicians. Much of what follows will be found to agree with what he has laid down, as well as with what has been written by the Abbé Buee and Mr Warren; but as I think that the view I have taken of the subject is more general than that which they have done, I hope that the following pages will be interesting to those who pay attention to such speculations.

Most granites result from partial melting within the crust. Granite melts produced at the lowest temperatures of partial melting mainly comprise close to equal amounts of the haplogranite components Qz, Ab and Or, with H2O. Many felsic granites were formed by partial melting under such conditions and are low-temperature types, with crystals of zircon and other restite minerals present in the initial magma. Such magmas evolve in composition, at least initially, through fractionation of that restite. If one of the four haplogranite components either becomes depleted or too low in amount to contribute further to the melt, then melting may proceed to higher temperatures without a contribution from that component. Melting will advance to significantly higher temperatures if there is a critical deficiency in one or more components and a high-temperature granite magma forms, in which zircon is completely soluble. Such magmas are extracted from the source in a completely molten state and may evolve by fractional crystallisation. They are monzonitic, tonalitic or A-type, depending on whether the critical deficiency occurred in the Qz, Or or H2O component. If the Ab component is critically deficient, as in pelitic rocks, the rocks may be infertile for granite production. The control that source rock compositions exert on both the physical and chemical properties of granite magmas provides a unifying element in granite gen

One of the rarest tetrapods in the East Kirkton fauna is an aïstopod represented by very fragmentary material of five individuals. It is described as a new species of the genus Ophiderpeton which is redefined and restricted to broad-snouted forms with large, robust teeth from the late Viséan and early Westphalian. Later Westphalian species are referred to the genus Oestocephalus.

The fossils which form the subject of this paper were collected in the summers of 1933 and 1934 by my son and myself at Earnstrey Hall Farm on the western slopes of Brown Clee in Shropshire. I had become interested in specimens collected at this locality by Mr W. Wickham King, M.Sc, which Sir Arthur Smith Woodward (1934, p. 566) named Corvaspis, and it was with the intention of obtaining further material of this genus that I got King to tell me exactly where he had found the best of his specimens. The section is in a small stream course 570 yards north 11° east of the farm and at the bottom of the escarpment formed by the “Psammosteus Limestone” and in the beds assigned to Zone I, 8 of King's classification (King, 1925). At the particular spot in question there is (in normal years) a waterfall over a 4-foot band of very tough calcareous pellet rock and conglomerate with occasional quartz pebbles up to about 1 inch diameter. This, especially its lowest few inches, had yielded the specimens that King had found, and from it we also collected abundant fragments of Corvaspis. Nearly all the specimens of Phialaspis (p. 439) which we discovered came from this rock, as did a fine example given by King to the British Museum and referred to later (p. 440). In 1934 the same rock yielded cf. Ctenaspis. Below this rock there is about 18 inches of grey shale, in which King had noted black streaks. This rests on several feet of red clay.

In order to understand the governing factors of petrological features of erupted magmas of island-arc or continental volcanoes, thermal fluctuations of subvolcanic silicic magma chambers caused by intermittent basalt replenishments are investigated from the theoretical viewpoint. When basaltic magmas are repeatedly emplaced into continental crust, a long-lived silicic magma chamber may form. A silicic magma chamber within surrounding crust is composed of crystal-melt mixtures with variable melt fractions. We define the region which behaves as a liquid in a mechanical sense (‘liquid part’) and the region which is in the critical state between liquid and solid states (‘mush’) collectively as a magma chamber in this study. Such a magma chamber is surrounded by partially molten solid with lower melt fractions. Erupted magmas are considered to be derived from the liquid part. The size of a silicic magma chamber is determined by the long-term balance between heat supply from basalt and heat loss by conduction, while the temperature and the volume of the liquid part fluctuate in response to individual basalt inputs. Thermal evolution of a silicic magma chamber after each basalt input is divided into two stages. In the first stage, the liquid part rapidly propagates within the magma chamber by melting the silicic mush, and its temperature rises above and decays back to the effective fusion temperature of the crystal-melt mixture on a short timescale. In some cases the liquid part no longer exists. In the second stage, the liquid part ceases to propagate and cools slowly by heat conduction on a much longer timescale. The petrological features of the liquid part, such as the amount of unmelted preexisting crystals, depend on the intensity of individual pulses of the basalt heat source and the degree of fractionation during the first stage, as well as the bulk composition of the silicic magma.

During the last few years Dr R. Kidston, F.R.S., has kindly entrusted to me for investigation certain specimens of fossil plants, showing structure, mostly from Lower Carboniferous horizons in Southern Scotland.

Four of these plants are dealt with in the present communication, namely:

Calamopitys radiata, sp. nov.

Calamopitys zonata Kidston, in MS. (now Endoxylon zonatum).

Bilignea solida Kidston.

Bilignea resinosa, sp. nov.

It will be understood that all the specimens were in Dr Kidston's hands in the first instance; the sections were cut under his direction, and he himself had determined the chief points in the structure of each before I began my observations. It only remained for me to work out the details, and to form my own views as to the probable affinities of the plants.

In late Ordovician and early Silurian times, the Girvan district lay in a shelf marinesetting on the margin of Laurentia, on the northern side of the Iapetus Ocean. The Lower Palaeozoic rocks of the Girvan district, and their shelly and graptolitic fossil fauna, were systematically described by Lapworth in 1882 and have formed an important research resource ever since. They provide valuable evidence for the depositional environment and geological setting of Girvan during the early Palaeozoic, in both regional and wider contexts, and demonstrate the long-recognised close affinity with contemporaneous Laurentian faunas. However, by late Ordovician and into Silurian times, the earlier Iapetus oceanic barrier to faunal migration had largely gone and there is good correlation between contemporaneous marine fauna throughout the British Isles and Scandinavia. Despite much recent research in the area, including resurvey work by the British Geological Survey, no comprehensive review of Silurian lithostratigraphy at Girvan has been published since the revision by Cocks and Toghill in 1973. The present review of the Silurian rocks addresses this need and complements the recently published (Fortey et al. 2000) revision of the underlying Ordovician rocks, thus bringing the entire Girvan Lower Palaeozoic succession up to modern standards of nomenclature.

It is confirmed that the type species of the genus Glyptoscorpius Peach 1882 is a subjective synonym of Adelophthalmus Jordan and Meyer 1854. Species which have been referred to Glyptoscorpius are reviewed and their present taxonomic position defined. Cyrtoctenus gen. nov., type species Cyrtoctenus peachi sp. nov., is designated to accommodate forms bearing five pairs of specialised abdominal appendages of which the first is comb-like. Four species of Cyrtoctenus from Devonian and Carboniferous rocks in Scotland, England, Belgium and Czechoslovakia are recognized. The structure and affinities of these forms are discussed with special reference to the comb-like appendages and their ornamentation in relation to these features in other arthropods. In particular the development of filaments and fulcra from different types of scales is discussed. The characters of the new genus are found to be so distinctive as to require the creation of the new order Cyrtoctenida for its accommodation.

There have now been described some fourteen hundred species of Tabanidæ, of which, according to Surcouf (1924), more than a hundred are European. Biological studies of the family have by no means kept pace with those of its taxonomy, and there is available comparatively little information regarding the post-embryonic development of individual species.

Examination of the literature showed that none of the European species had been investigated with any degree of detail, and it was with the intention of supplying at least part of this want that the present study was undertaken in 1930. Because of its relative abundance from June to August in rural districts of Scotland, the common cleg, Hœmatopota pluvialis, L., was the species first chosen. The interest of this choice was considerably increased by the relisation that the biology of no species of Hœmatopota had previously been submitted to careful examination either in Europe or elsewhere.

Material excavated from a trench dug to expose the Rhynie Cherts Unit of the Dryden Flags Formation included blocks of Rhynie chert up to 50 cm thick and comprising the full thickness of plant-bearing chert beds. These blocks, and others collected as float, display a variety of macro-textures typical of silicification at the terrestrial surface and in shallow water. On sandy terrestrial surfaces, autochthonous and allochthonous plant debris and plant rhizomes are well preserved, but aerial axes generally decayed prior to silicification. In shallow water, clonal plants, particularly Rhynia, are preserved with aerial axes in growth position, supported by microbial mats and meshworks. Preservation of such delicate fabrics required the creation of a load-bearing framework early in the silicification process, to prevent crushing during early burial.

On the microscale, plant taphonomy reveals characteristic features due to plant decay prior to silicification in both wet and dry conditions, and also during the silicification process. Silicification of plants was frequently very rapid, preserving delicate transient features such as spore germination and ejection of sperm cells from antheridia. In situations where plant tissue continued to decay during silicification, the process was slower.