154 THE ESSEX NATURALIST. marine work. It could be used either as an independent unit or as an adjunct to a permanent coastal station, if such were in existence. Here again it might be possible, if the need were made known, that an offer of a suitable boat for certain periods would be forthcoming from one of the Field Club's members or friends. My task is now nearly accomplished. I have tried to show you that, as a Field Club, we have a certain responsibility for the investigation of all kinds of life, down to the most minute forms, occurring in our inland, estuarine and coastal waters ; that the problems attaching to such investigation are both numerous and important; and, further, that there are a number of ways by which we could, as individuals and collectively, do more perhaps than we have done in the past to encourage the study of aquatic biology. I will conclude with the expression of the hope that what has been said will at least help towards a truer perspective of the place of aquatic biology in Field Club work, and that it will have some repercussion in our future activities on the biological side. THE BIRDS OF THE THAMES VALLEY (ESSEX ONLY) in 1926, 1927 and 1928. (With 1 Plate.) By WILLIAM E. GLEGG, F.Z.S., M.B.O.U. SEVEN years have elapsed since I commenced to observe the birds frequenting the Essex estuaries, and the pre- sentation of this article, the fifth of the series, brings the under- taking to a not unsuccessful conclusion. Observations have been carried on from Dagenham at the one end to New England Island on the other, and, with the exception of those portions, strictly preserved by the War Department, between Rainham and Purfleet, and between Shoeburyness and Wakering Stairs, and the section between Grays and West Tilbury, which is impossible, the whole of the river has been traversed, much of it on many occasions. Bird study is followed, at times, with considerable difficulty, for the bank of the river has been very much interfered with by various commercial enterprises. Serious changes are taking