Every one of these motions has left its mark on our language, though the traces of the earliest immigration of all—that of the Celts—are rather scarce. The clearest vestiges of it are to be found in the proper names of our rivers, for a surprising number of these contain one or other of the various Celtic terms for ‘water’ or ‘river’, e.g. _avon_, _dwr_ (_ter_ or _der_), _uisge_ (_wye_, _usk_, _is_, _ax_), while the other parts of the name are often composed of words for ‘water’ taken from another Aryan language, as in _Derwentwater_, _Windermere_, _Easeburn_, _Ashbourne_,... An ingenious theory has been evolved to account for this. In the case of the _Dur-beck_ in Nottinghamshire, and the _Dur-bach_ in Germany, it has been supposed that in the first place a body of Celtic immigrants squatted by the side of a stream which, as they were not extensive travellers, they knew simply as the _dwr_—‘The Water’. Their Teutonic successors inquired the name of the stream, and on learning that it was _dwr_, naturally assumed that this was a proper name. They accordingly adopted it, and tacked on one of their own words for ‘water’—‘bach’ or ‘beck’, just as we may speak of the ‘Avon River’ or the ‘River Ouse’. The phenomenon occurs so persistently both in this country and all over Europe that this explanation can hardly be altogether fanciful. The four hundred years of Roman colonization, following Julius Caesar’s landing in 55 B.C.—years which left such permanent and conspicuous vestiges on the face of England—have made little enough impression on her language. Fresh as the memory of that civilization must have been when the Angles and Saxons arrived, they seem to have learnt nothing from it. A few towns, such as _York_ (Eboracum), retain in a more or less corrupted form the particular titles given to them by their Roman founders, but outside these almost the only Latin words which our ancestors can be proved to have taken from the Britons are _port_ and ‘castra’ (a camp), surviving to-day in _Chester_ and in the ending of many other town names such as _Winchester_, _Lancaster_, _Gloucester_,...