South-eastern Scotland Research Articles

Bilateral Asymmetry: a Larval Polymorphism in some Argid Sawflies (Hymenoptera, Symphyta)

BILATERAL asymmetry is virtually unknown among insects, other than as a rare aberration. Pasteels1 has briefly noted the occurrence of colour asymmetry in larvae of Arge ustulata (L.) in Belgium and the Tyrol. Intensive collecting in south-eastern England and northwestern Scotland has shown British populations of A. fuscipes (Fallen) and A. ustulata feeding on birches (Betula pendula Roth, and B. pubescens Ehrh.) to consist of symmetrical and asymmetrical individuals. Both forms appear to be present in proportions too large to be attributable to recurrent mutation alone. Unfortunately, however, samples from particular localities have so far been too small to allow accurate frequency determinations. Nevertheless, assuming genetic control, this phenomenon, would appear to constitute a true polymorphism (Ford2).

Cultivation terraces in South-eastern Scotland

The literary evidence provides some grounds for the argument that the terraces are probably not of later date than the late Middle Ages and had gone out of use by 1700 at the latest. A gazetteer of 136 sites is included.

Four granitic intrusions in south-eastern Scotland

The Silurian strata of Mid Lothian, East Lothian, and Berwickshire were invaded in early Devonian times by numerous igneous masses. Most of these intrusions are quartz-porphyrites, but a few are of more granitic texture, notably those of Broad Law in Mid Lothian, of Priestlaw in East Lothian, and of Cockburnlaw and Lamberton Beach in Berwickshire. These four igneous masses form the subject of the present communication. The Cockburnlaw intrusion will be considered first as it is the largest in area and shows the greatest variety of rock-types. All the rock names employed in the description are used in accordance with the recommendations made by the Committee on British Petrographic Nomenclature,1 with the following exceptions:— When the names granite and syenite are enclosed by inverted commas their old field significance is implied. The term hyperite is only used with particular reference to the Galloway rocks described under that name by Sir J. J. H. Teall. Cockburnlaw. The ‘ granite ’ mass which forms the eminences of Cockburnlaw and Stoneshiel Hill lies some three miles to the north of Duns and is admirably dissected by the River Whiteadder. W. Stevenson2 and Sir Archibald Geikie 3 have fully described the field relations of the intrusion, and a further detailed account is thus rendered superfluous. The igneous rock covers an area of about one square mile and is intrusive into grey wackes of Upper Silurian age which have undergone intense thermal metamorphism. At Cockburn Mill (see Fig. 1) the igneous rock

THE GLACIER LAKES OF CLEVELAND

In pre-glacial times Yorkshire seems to have stood at a considerably greater elevation than at present, for drift-filled valleys have been proved to descend in many places below sea-level. In the great valley between Newcastle and Don-caster there is an old drift-filled hollow, which at Gateshead is 140 feet below O.D. South of the Tees borings reveal a great depth of drift until the line joining Northallerton and Bedale is reached, where it becomes thin over an old watershed, but thickens again southwards, and the rock floor of the valley is 74 feet below O.D. at Cawood, and 170 feet at Barnby Dun, near Doncaster. In the Vale of Pickering drift deposits reach a thickness of 107 feet, and the rock floor from Filey to Malton lies below sea-level. This evidence points to a long period of pre-glacial elevation, but, on the other hand, borings in Holderness show a plain of marine erosion, with blown sand banked against the old chalk cliff, at practically the present level. Generally over the coast region of Yorkshire two boulder clays have been identified. An upper clay, reddish and almost devoid of boulders, and a lower clay, which is bluish, and contains many erratics. The erratics in the Cleveland area may be grouped into three divisions, according to the place of origin :— I.—Western Group. South-western Scotland. Lake District and Vale of Eden. Teesdale and Pennine Chain. II.—Northern Group. South-eastern Scotland and the Cheviots.[*][1] Eastern Durham. III.—Eastern Group. Christiania region. Gulf... [1]: #fn-1