Over most of North-Western Europe the occurrence of river-terrace deposits containing Palæolithic implements has been long known, and the establishment of a sequence of forms among these implements has resulted from the researches of Continental, and especially of French archæologists. With the pioneer work the name of M. Boucher de Perthes, of Amiens, will always be associated. His was the task of convincing unwilling minds of the human workmanship of the ancient flint-weapons found in the gravel-pits of the Somme Valley. For the next great advance we owe a debt of gratitude to another French savant, the late Professor Victor Commont, for his life-work was the taking up of the researches of his predecessor and establishing the sequence of cultural types and their relative chronology.

Dr. Charles Doolittle Walcott acquired a taste for geology and natural history when very young. As a schoolboy he made large collections in the region of his home, and determined to follow a scientific career if possible.

The Devonian rocks in Devon, like those of the Old Red Sandstone of which they are the equivalents, have been divided into three groups. Mr. T. M. Hall, writing in 1879, quoted no less than five separate classifications suggested for the beds of North Devon, nor has uncertainty been removed by the conclusions arrived at by geologists since that date. But we may for present purposes take the following as the nearest approach to a generally accepted succession:—

While examining the rocks of the Middle and Upper series for fossil plants during the past eleven years (1907–18), the results of which have already in part been published, other discoveries were made incidental to the work of collection of plant remains. Among these the discovery of fossil fish remains seems worthy of special notice.

It is curious how readily the public misconceives even the most simple of scientific problems. A plausible theory, no matter how fallacious, will gain an immediate currency which it is difficult to undermine until it has run its course. Such theories do harm to the public, to industry, and to science, and they should be combated rather than avoided, so that the mischief may be curtailed, if not entirely eliminated.

In pressure-modified gneisses and schists certain minerals are often distinctly secondary in formation; actinolitic hornblende replaces ordinary hornblende in a gneiss, as on the southern side of the St. Gotthard Pass (31), or in a dark mica-schist, as in the Binnenthal (32), or a tremolite appears in marble near the Campolungo Pass (33). A mixture of crushed hornblende and felspar gives rise to a biotite, small flakes of which may be built, like bricks, into a newly-formed large crystal of hornblende, especially towards its exterior (34). Glaucophane in hornblendic rocks, such as diorites and eclogites, is often a secondary mineral (35), some constituents derived from a crushed soda-felspar having combined with those of the original hornblende. Rather large biotites have formed in a dark mica-schist in the Binnenthal, and here also some of them have been developed at right angles to the main pressure, but others in the direction of it (36). Scales of chloritoid, sometimes a third of an inch in diameter, are secondary formations in some gneisses and chloritic schists, and kyanites in some micaceous schists suggest a possible reconstruction of an original mineral. Chlorite itself is a mineral of secondary origin, and such rocks as smaragdite-euphotide (37), saussuritic gabbro, and possibly even ordinary gabbro are all more or less altered from their original condition, and in some at least of these cases pressure may have been a factor in the change.

Professor Charles Lap Worth, in his “Sketch of the Geology of the Birmingham District”, gives a list of species (pp. 343 and 349) from “the Hyolite Limestone” and the associated shales as provisionally determined by Miss E. M. R. Wood (Mrs. Shakespeare). He referred the beds generally to the Lower Cambrian and paralleled them approximately with the fossiliferous beds of Comley, the details of which had not then been worked out. The present study of the Hyolithidæ, etc., of Woodlands Quarry, fully confirms the reference to the Lower Cambrian, and it would seem that the position of the Hyolite Limestone in the faunal sequence is near to or a little below that of the Olenellus and Grey Limestones of Comley at the local summit of the Lower Cambrian. The evidence of this is indirect, for no species has yet been identified from both localities, unless it be Micromitra labradorica, Billings sp. Nevertheless, the Hyolithidæ, etc., found in North America that are nearest to, or representative of, those of Hartshill, are there associated more or less intimately with a number of trilobites and brachiopods that find their representatives in the Comley Limestones.

Abyssinian Deposits.—During 1911 an Italian resident in Eritrea discovered a remarkable occurrence of potash salts in the Piano del Sale, near the provisional boundary between the Italian colony and Abyssinia. On account of its equivocal situation, development was somewhat handicapped during the early stages by Abyssinian hostility. Fortunately these preliminary difficulties were successfully overcome, and the deposit proved to be of great assistance to the Allied Powers during the war. The rate of production has gradually increased, and the estimated output for 1918 is stated to be equivalent to 50,000 tons of KCl.

Whilst the basis of the prosperity of a country is admittedly agriculture, its industrial growth is founded on mineral resources, and its participation in the world's markets is chiefly dependent on the extent to which these raw materials can be applied to home manufactures.

The hydraulic limestone series which cap the Silurian rocks of the New York sections, and are commonly embraced under the name “Salina Group”, are probably the richest known depository of remains of the Merostome Crustacea. During the past fifteen years we have been engaged upon the study of this fauna, and the results at which we arrived in our memoir on the Eurypterida of New York could not have been safely attained without the previous labours of Dr. Woodward and the late Professor Rupert Jones, of Huxley, and Hugh Miller for the British species; of Friedrich Schmidt, Nieszkowski, and Holm for the species of the Baltic basin.