In June last (1927) Mr. K. E. Williams and I received the following letter from Mr. R. Hecker, who is in charge of the Siberian Collections at the Geological Museum, Academy of Sciences, Leningrad:—

Dr. C. G. S. Sandberg's article on the origin of the Dwyka Conglomerate calls for a wider publicity of the facts connected with the early establishment of the glacial origin of that deposit. The general history of the matter is given in the Geology of South Africa, by Drs. Hatch and Corstorphine, second ed., p. 14. The original determination was made by Dr. P. C. Sutherland in his Geology of Natal, Pietermaritzburg, 1868, but a number of geologists discussed it subsequently, such as C. L. Griesbach, E. J. Dunn, A. G. Bain, R. N. Rubidge, A. Moulle, G. W. Stow, R. Pinchin, A. R. Sawyer, G. A. F. Molengraaff, A. Schenck, and A. Stapff. Among the diversity of opinions expressed it was difficult to arrive at any definite conclusion at that time. In September, 1895, Dr. R. Marloth submitted to a meeting of the South African Philosophical Society a number of boulders which he thought showed glacial striations, but the evidence was not considered satisfactory by Dr. Corstorphine or myself, the only two geologists in the country.

In September, 1926, accompanied by my friend, Mr. James Begg, of Glasgow, I spent a few days in the Clitheroe district, being attracted thereto by a perusal of that excellent paper by Dr. Parkinson on this region (Q.J.G.S., vol. lxxxii, 1926, pp. 188–249). The paper itself, with its interesting details, really fanned into flame a smouldering desire to examine the district further, since over twenty-five years ago I had read in Our Common British Fossils, by the late Dr. Taylor—a fascinating book to a young geologist—the statement that in the neighbourhood of Clitheroe. whole beds are composed of crinoid heads. Being in Lancashire shortly afterwards, I one day went to Clitheroe and spent a few hours in Salt Hill Quarry, but owing to ignorance of the localities and lack of experience in crinoid collecting, I was grievously disappointed so far as these fossils were concerned. When Mr. Begg and I visited the district in 1926 I recognized the landmarks and saw at once that if I had gone further east to Bellman Quarry I should probably have been amply rewarded. On the results of our 1926 visit Mr. Begg and I were well pleased. We explored most of the knolls and quarries of the district and spent a considerable time, especially at Bellman and Coplow Quarries, where we collected a large number of well-fcpreserved crinoids.

The complex structure of the Lickey Hills, 7 miles south of Birmingham, has attracted the attention of geologists since the early part of last century, and interpretations of some details of their geology have been almost as numerous as the observers. The hills form part of the district recently remapped on the 6-inch scale by the Geological Survey.

The fossil deposit here described is situated on the west bank of the Red River, 3 miles (in a direct line) south of its junction with its western tributary, the Assiniboine River. More specifically the deposit is situated about 50 yards from the residence built by the late Colonel Thompson in Fort Garry, a suburb on the southern outskirts of the city of Winnipeg.

Of late years a great deal has been written on the genesis of ore-deposits, and in particular much space has been devoted to more or less controversial discussions of the possibility of a magmatic origin for many important types, both in individual instances and by way of generalizations. The widespread acceptance in many quarters of a belief in the derivation of such deposits on a wholesale scale from igneous magmas may perhaps to some extent be regarded as a natural reaction from some of the theories of markedly contrasted character that prevailed almost universally in past times. The “swing of the pendulum” is such a well-known psychological phenomenon that it is unnecessary to enlarge on it here. It is applicable to nearly all branches of knowledge, and of ignorance, and was long ago summarized in the law that action and reaction are equal and opposite. If a theory is pushed too far, it is inevitable that in a while it will be regarded as wholly, or for the most part, erroneous, although it may nevertheless contain a good deal of truth. Most of these difficulties and controversies arise from the ineradicable habit of generalizing too broadly, and the rest of them can generally be traced to misunderstandings as to the precise meaning of the terms employed. In the history of the scientific study of ore deposits both of these sources of error have undoubtedly played an important part.