Twelve years ago Priestley and Ewing (1923) reported that in certain plants, normally showing but little development of stem-endodermis, an extensive formation of this layer could be induced by etiolation. (Note: In this paper the term endodermis is used only when the layer shows characteristic structural features—in the present case the Casparian strip.) A later paper by Priestley (1926) dealt with the same subject. The specified plants with which this result was obtained consisted of four closely related species, namely, Vicia Faba, V. sativa*, Pisum sativum, and Lens esculenta*, and also Solanum tuberosum. (The statements relating to the species marked with an asterisk are based on unpublished work carried out at Leeds, kindly placed at the author's disposal by Professor J. H. Priestley.) In these plants a primary endodermis, though present only at the base of the normal shoot, was described as extending to a considerable height in the etiolated shoot. It was concluded that the absence of endodermis from the greater part of the shoot of these plants, when grown under normal conditions, arises from the inoperation, in the presence of light, of the mechanism forming the Casparian strip.

St Kilda (Pl. V), the largest of a group of four islands located some 50 miles west of Harris in Latitude 57° 49′ N., Longitude 8° 34′ W., has an extreme length and breadth of 2½ by 1¾ miles and a circumference of about 8¾ miles. The highly indented coast-line is guarded by almost impregnable cliffs except in the Village Bay or Loch Hirta where there is a strip of sand a quarter of a mile long backed by a great storm-beach. The two principal inlets of the sea, Village Bay or Loch Hirta, and the Glen Bay open to the south-east and north-west respectively.

The genus Lyginorachis was proposed by Kidston (1923, pp. 18–19) to accommodate isolated petioles which, whilst their structure was similar in some respects to that in the petiole of Lyginopteris, could not be finally identified with the latter genus. Two species of Lyginorachis have been described (Scott, 1923, pp. 57-60; Crookall, 1931, pp. 27-34, pls. i-iii). Both came from Scottish Lower Carboniferous rocks; the one, Lyginorachis papilio Kidston and Scott, from the Cementstone Group (Calciferous Sandstone Series) at Norham Bridge on the Tweed, and the other, Lyginorachis Taitiana Kidston and Crookall, from the Auldton Limestone (Carboniferous Limestone Series) near Lesmahagow, Lanarkshire. Crookall also described a smaller and simpler petiole (loc. cit., pl. ii, fig. 3) as Lyginorachis sp., from the Cementstone Group at the Langton Burn, near Duns, Berwickshire.

Investigations have been made into the conditions of sedimentation of the Ordovician rocks of the Girvan district, with special attention to a series of greywackes, the Ardwell Beds, which are remarkable for frequent intraformational disturbances and unconformities.

In presenting the evidence it is proposed to follow the stratigraphical classification of Peach and Horne (1899), who, after careful consideration, adopted Lapworth's (1882) succession, except for a few minor alterations. These authors pointed out that the Llandeilo rocks north of the River Stinchar consist of Kirkland Conglomerate, Stinchar Limestone Group, and Benan Conglomerate, while south of the river they are represented by Tappins Greywackes and Glen App Conglomerate (see table p. 488).

Few plants of Carboniferous age have appealed so strongly to the scientific observer as the huge woody trunks of a coniferous type that have been discovered from time to time in beds of that system. The appeal has come from different points of view at different times; thus these trees were hailed by Witham (1831, pp. 1–2), Lindley and Hutton (1831, p. xiii), and Hugh Miller (1849, p. 186) as evidence of the existence of higher coniferous plants in abundance during a period to which the current consensus of scientific opinion had assigned only members of the lower plant families, or would admit only an infrequent occurrence of higher forms. These remains were therefore important in discussions concerning the development of plant life, and were cited by Hugh Miller (1849, p. 185) in his attempt to combat the then embryonic ideas of evolution—the recrudescence of Lamarckian ideas—current under the name of “the development hypothesis.” Miller, however, recognised one significant point, namely, that they represented a land flora as distinct from one occupying a water habitat (1849, p. 202).

In order to study the ecology of intertidal plants and animals it is desirable to choose a coast-line which is as simple as possible. When numerous factors vary simultaneously it is impossible to decide which of them is responsible for any change which may occur in the flora and fauna. The complexity of a shore which is ravined or boulder-strewn makes ecological work difficult. Unfortunately, certain major influences, such as wave action, involve a whole complex of subsidiary effects, so that the perfect locality, where each environmental factor would be found to vary in turn independently of all the other factors, cannot exist.

This research was begun in 1929, and a preliminary account of some of the results of the investigation was published in the Journal of Anatomy, January 1932. It was initiated by the discovery, during experiments on intravitam staining in the guinea-pig, that dye-bearing cells collected in large numbers in the endometrium of the uterus and that their incidence there was cyclic. The first results were obtained in animals injected immediately after parturition and killed at intervals thereafter. In a short series of virgin animals, the series being established by determining the date of heat by the vaginal smear method (Stockard and Papanicolaou, 1917, 1919), practically identical results were obtained.

Raasay, one of the major islands of the Inner Hebrides, lies between the Isle of Skye, from which it is separated by the Sound of Raasay, on the west, and the mainland district of Applecross on the east. From Rudha na Cloiche, the southernmost promontory, to Rudha nan Sgarbh in the extreme north, the island has a length of over 13 miles, while the breadth from west to east varies from 3 miles near Ósgaig to a ½ mile just south of Arnish or at An Caol. The total surface area is about 27 square miles. The island is separated from Rona on the north by Caol Rònach, studded with islets and submerged rocks, a little more than a mile wide.

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.

With the renewal of activities in Fishery Research, which took place in the lands bordering the North Sea after the War, fresh lines of investigation were introduced. Amongst others, quantitative surveys of the bottom fauna similar to those carried out by Petersen were undertaken by several countries. The southern part of the North Sea was examined by the Ministry of Agriculture and Fisheries and the results were published by Davis (2, 3). Other work undertaken in the German Bight was published by Hagmeier (6). A small survey was carried out by Petersen (8) in the North Sea off the north-west coast of Denmark. Areas to the north and west of Scotland, as well as the northern half of the North Sea, were surveyed by the Fishery Board for Scotland and a preliminary account published (11). The present paper is, in part, a summary of the results of the survey work carried out by the Fishery Board for Scotland in the northern part of the North Sea during the years 1922-25, supplemented by a subsequent survey of the intertidal areas undertaken privately; in part an analysis of the faunistic divisions of the North Sea based on the distribution of the molluscs, especially lamellibranchs, as recorded in the above papers. So far as the North Sea is concerned, the area covered by the Scottish investigations is bounded on the south approximately by latitude 56° N., and on the east and north by the 200 m. (100 fm.) contour.

The first part (5) of a study of the quantitative distribution of the bottom-fauna in Scottish waters, and of the natural faunistic divisions of the North Sea and adjacent areas, dealt with the distribution of the molluscs in the North Sea. In this paper the echinoderms from the same area are treated on similar lines. In addition the natural faunistic divisions, as shown by the distribution of the dominant species of molluscs and echinoderms, and the validity of Petersen's community concept as applied to the North Sea, are discussed.

Reference should be made to the earlier paper for information concerning the methods of collecting, the area covered by the Scottish surveys, similar surveys carried out by other workers in the remaining parts of the North Sea, the number of hauls in each square, and other introductory matters.

The shell and gizzard plates of Philine aperta were first described in 1616 by Fabius Colonna. Linnæus (1767) included the animal in his genus Bulla, and named it Bulla aperta. In 1772 Ascanius made a new genus, Philine, with P. aperta as type.

Cuvier (1810) created the order Tectibranchiata, and in the “Règne Animal” (1817) grouped in this order Pleurobranchus, Aplysia, Dolabella, Notarchus, Bulla, and Philine.

Fischer (1887) divided the Tectibranchs into the Cephalaspidea, the Anaspidea, and the Notaspidea; the first with a cephalic disc, the last with a dorsal shield, and the Anaspidea with neither.

The purpose of this communication is to describe, and to discuss the significance of, (1) the extensive morainic deposits and the associated glacial phenomena of the tract of country situated immediately west of the Ochil Hills (border of Perthshire and Fifeshire)—between the River Teith near Doune, north of Stirling, and the River Tay in the vicinity of Perth; and (2) a well-marked later glaciation studied in the region of Loch Lomond and the Upper Forth valley.

In both instances these glaciations involved readvances of the ice during the retreat of the last general ice-sheet, and for brevity and convenience of description they will be referred to as the Perth Readvance and the Loch Lomond Readvance.

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.

The problems of regeneration, and those relating to the production of adventitious structures in general, have not been extensively studied in the Lycopodiales, although the production of adventitious structures, some of them regenerative in nature, has been recorded for all four of the living genera. Selaginella has been examined more thoroughly in this respect than the other three genera. Adventitious roots have been induced to develop from decapitated rhizophores and from isolated lengths of stem; the production of adventitious shoots from rhizophore rudiments has also been obtained by experimental methods. Goebel (7, p. 1220) has described the development of adventitious buds on the leaf bases of Isoetes lacustris, and Osborn (12) has described interesting regenerative developments from detached leaves of Phylloglossum Drummondii. A number of examples of regeneration in various species of Lycopodium has been recorded. Goebel (5, p. 46) states that the first leaves of embryo plants of L. inundatum may produce adventitious shoots. The same writer (6, p. 83) has recorded, but not described in detail, the development of adventitious outgrowths from the decapitated shoots of young plants of L. Selago and from isolated bulbil leaves of the same species. The development of adventitious buds on isolated roots and leaves of L. ramulosum has been described by Holloway (8).

In the 'eighties of last century R. G. Symes and A. McHenry mapped the schists of Antrim for the Geological Survey of Ireland. They made abundant records of dip, which are still valuable though, owing to the difficulty of the subject, not uniformly reliable. They also indicated outcrops of limestone at Torr Head and, 8 miles inland, at Glenshesk and Breem. The schist area of Antrim is contained in Sheets 8 and 14 of the one-inch to the mile Geological Survey Map of Ireland (text-fig. 1).

1. During recent years increased attention has been paid to the question of measuring or estimating the extent or degree of disturbance in the earth's magnetic field. Two distinct purposes have been kept in view. The first and more general is to provide some measure of disturbance capable of use as a means of correlating terrestrial magnetic change with other geophysical or cosmical phenomena; in particular, solar phenomena. The second seeks to assign to each Greenwich day a numerical value for the degree of disturbance on that day, so that a selection may be made in each month of a certain number of days on which the terrestrial field has been least or most disturbed. The immediate object here is to secure comparability between results—particularly diurnal inequalities—obtained at different magnetic observatories.