If we take a general view of the present position of geological science, we are struck by the fact that, although there is substantial agreement amongst geologists on matters relating to the origin of the rocks usually designated as aqueous and igneous, the greatest diversity of opinion prevails with regard to the circumstances under which the so-called metamorphic rocks have been produced. Every fragment of evidence calculated to throw light on the origin of these rocks, therefore, deserves the most careful consideration. Of recent years special attention has been directed to the effects of mechanical energy in modifying the mineralogical and structural characters of rocks originally formed by aqueous and igneous agencies; and a suspicion has been aroused that it is in this direction that we must look for a solution of many of the problems connected with the origin of the crystalline schists. A visit to the Lizard Peninsula of Cornwall during the present summer has convinced me of the immense importance of this view so far as that district is concerned. That portion of the peninsula which lies south of a line drawn from Porthalla on the east to Polurrian Cove on the west is formed.partly of igneous rocks—such as gabbro, greenstone, serpentine, and granite—and partly of crystalline schists. The igneous rocks, in certain places, become foliated and sohistose and sometimes show a definite banding due to a variation in the relative proportions of the different constituents. In other words they present characters which are usually regarded as distinctive of the crystalline schists. There is, moreover, evidence to show that these characters are mainly the result of a yielding to earth-pressure subsequent to the consolidation of the original rock. At the present moment, having just returned from the district, I am unable to treat the subject from a general point of view with any prospect of success; but it has occurred to me that some details with regard to one of the rocks may not be without interest to members of the Association.

Much interest has been recently aroused in the exploration of the caves of the Vale of Clwyd, partly by the enthusiasm of the principal promoter of the investigation, Dr. Hicks, but chiefly owing to the inferences he has drawn from the observations made. When reading the Report of the British Association Committee for the Exploration, of which he was Secretary, he assumed the entire responsibility of those theoretical deductions. In these, however, he was supported by all the speakers who followed him on the subject, including the other members of the Committee excepting myself. He had previously anticipated the report by the announcement in Nature of his discovery of Pre-Glacial Man in the Vale of Clwyd. I therefore ask leave briefly to state my reasons for differing from his conclusions.

Amongst others found by Dr. H. K. Warth, the particular pebble referred to was picked up by its discoverer on the 10th of June, 1886, in about lat. 32° 48' N. and long. 73° 15' E. Its size is 3¼ inches by 2¼ by 2 inches; and its weight is 10¼oz. The material is felsitic rock, the colour reddish-brown, and its density= 2·608 (that of albite being 2·59—2·64).

The block of stone in question, like another exhibited by Mr. A. B. Wynne, was obtained by Dr. Warth, at Chel Hill, in the Punjab Salt Range. This specimen was sent by Dr. Warth to Mr. H. B. Medlicott, Director of the Geological Survey of India, who forwarded it to the present writer, in the hope of learning the views of those who have most experience of similarly marked boulders, and of ascertaining whether the peculiar characters of the present specimen are due to any particular form of ice action or to any other agency.

Our attention has been devoted exclusively this year to the fossil flowering or phanerogamous plants. The results of our researches point to the conclusion that while that section known as Gymnospermous, to which the Coniferæ belong, is of the highest antiquity, being almost coeval with the first definite remains of plants in the Palæozoic age, there are no Angiospermous plants in British rocks of greater antiquity than the Secondary period, if we except the problematic plant known as Spirangium. Even down to so late as the Lias we have been unable to ascertain that any indisputable Angiosperm has been discovered within our area, for we are led to the conclusion that the supposed Monocotyledons from the Rhætics, near Bristol, hitherto referred to the family of Pond-weeds under the name Najadita, are really cryptogamic plants of the moss tribe, closely allied to the river moss Fontinalis. This group had not previously been found fossil, and, so far as it goes, would indicate rather a temperate climate. It is important to notice that these conclusions are shared by such high authorities on fossil plants as Prof. Williamson, Mr. Carruthers, and by all botanists who have examined them, as well as Mr. Brodie, the possessor of the specimens. The Lilia, Bensonia, and other supposed Monocotyledons of similar age are very imperfectly preserved and, doubtless referable to Cycads, a family which abounded then.