Still the classification rests on a practical truth. Although each dialectal feature has its own boundaries, these are not set by pure chance. Their position is to some extent governed by old tribal and political divisions, by the influence of large towns which served as commercial and administrative centres, and by relative ease of communication. Consequently, linguistic features are roughly grouped, and it is _a priori_ likely that London and Oxford would have more features in common than would London and York, or Oxford and Hull; and similarly it is likely that for a majority of phenomena York and Hull would stand together against London and Oxford. Such a grouping was recognized in the fourteenth century. Higden and his authorities distinguish Northern and Southern speech (XIII _b_); in the Towneley _Second Shepherds' Play_, ll. 201 ff., when Mak pretends to be a yeoman of the king, he adopts the appropriate accent, and is promptly told to 'take outt that Sothren tothe'. In the _Reeves Tale_ Chaucer makes the clerks speak their own Northern dialect, so we may be sure that he thought of it as a unity. But had Chaucer been asked exactly where this dialect was spoken, he would probably have replied, _Fer in the North,—I kan nat telle where_. A dialect has really no precise boundaries; its borders are nebulous; and throughout this book 'Southern', 'Northern', &c., are used vaguely, and not with any sharply defined limits in mind. The terms may, however, be applied to precise areas, so long as the boundaries of single dialect features are not violently made to conform. It is quite accurate to say that _-and(e)_ is the normal ending of the pres. p. north of the Humber, and that _u_ for OE. _y_ is found south of the Thames and west of London, provided it is not implied that the one should not be found south of the Humber, or the other north of the Thames. Both in fact occur in _Gawayne_ (Cheshire or Lancashire); and in general the language of the Midlands was characterized by the overlapping of features which distinguish the North from the South. From what has been said it should be plain that the localization of a piece of Middle English on the evidence of language alone calls for an investigation of scope and delicacy. Where the facts are so complex the mechanical application of rules of thumb may give quick and specious results, but must in the end deaden the spirit of inquiry, which is the best gift a student can bring to the subject. § 3. VOCABULARY. The readiness of English speakers to adopt words from foreign languages becomes marked in fourteenth-century writings. But the classical element which is so pronounced in modern literary English is still unimportant. There are few direct borrowings from Latin, and these, like _obitte_ XVI 269, are for the most part taken from the technical language of the Church. The chief sources of foreign words are Norse and French.