336 PLEISTOCENE GEOLOGY OF THE THAMES VALLEY. Nuts imbedded in a tree-trunk.—About the middle of December last, some large elm trees were cut down in a field belonging to the late Mrs. Mildred, at Chigwell. At the base of one of the trees, about 5 feet from the ground, in the centre of a trunk 18 inches in diameter, was found a quantity of nuts -the fruit of the Hazel They were most perfect, but on being opened, the kernels were perished. There was no opening in the trunk or any communication of any kind with the outside, so that these nuts may have been deposited by a squirrel more than a century ago. It appears from several instances of the kind that trees quickly close up articles deposited in a chink or hollow. I exhibited a blade of a razor extracted from the heart of a horn-beam in the Forest at the meeting of the Club on February 25th, 1899 (ante page 27).—S. Arthur Sewell, Buckhurst Hill. [Several occurrences of a similar kind are recorded in our publications. In 1883 Mr. Edinger gave an account of the finding of a bird's nest with eggs in it, enclosed in the wood of an elm tree (see Journal of Proceedings, E.F.C, vol. iv., iii.), and Mr. C. E. Benham in 1894 recorded an example of inscribed letters having been covered up for many years by the growth of the woody tissue of an elm near Colchester. Essex Nat., vol. viii., p. 88.—Ed.] CONTRIBUTIONS TO THE PLEISTOCENE GEOLOGY OF THE THAMES VALLEY. I. THE GRAYS THURROCK AREA, PART 1. By MARTIN A. C. HINTON and A. S. KENNARD. WITH A SUB-SECTION ON THE FOSSIL FISHES. By E. T. NEWTON, F.R.S., F.G.S. [Read October 27th. 1900.] I. INTRODUCTION. It is to be doubted if any geological period is of greater interest than the Pleistocene, for it is the borderland of geology and history. From the early days of geological enquiry to the present time, it has attracted the attention of many of the ablest intellects who have striven to unravel the tangled web of the earth's past history. Dr. Buckland, Sir Charles Lyell, Sir Joseph Prestwich, William Whitaker, Professor James Geikie, the Woods, father and son, Alfred Tylor, John Brown, F. W. Harmer and many others too numerous to mention have endeavoured to read the secret hidden in the beds often spoken of as the "Drift," and yet in spite of this research there is no branch of science where there is greater