s. 32. If we inquire further, why there should have been any difference of development in such cases, and how the same form could, apparently, yield both an open _[=e]_ and a close one, I believe that a clear answer can be given. For it is precisely in such cases that we find different forms in the Old Mercian (or Midland) dialect and in the A.S. (or Southern). Thus, whilst the A.S. (Southern) form of 'deed' was _d[=ae]d_, the Mercian form was _d[=e]d_. In fact, the mod. E. _deed_ is clearly Mercian, and that is why it is not spelt with _ea_ in Elizabethan English. Hence Chaucer had, ready to his use, two forms of this word. One was the Southern _d[`e][`e]d_, with open _[=e]_, from A.S. _d[=ae]d_; the other was the Midland _d['e]['e]d_, with close _[=e]_; and, as the Midland dialect was then rapidly gaining the ascendency, he could hardly go wrong if he sometimes used the more popular form. Chaucer knew nothing of etymology, but he knew how words were pronounced by his cotemporaries; a fact which sufficiently explains his habits. In order to complete this part of the case, it is necessary to add that the M.E. _[=e]_ which results from A.S. _[=e]a_ is ALWAYS open[31]. s. 33. A similar ambiguity occurs in the case of a long _e_ which we should expect to be close. Here again we must distinguish between two kinds. The A.S. _[=e]o_ yields an M.E. _[=e]_ which is ALWAYS close; as in _d[=e]op_, deep, M.E. _d['e]['e]p_. Again, there is an A.S. _[=e]_ which results from mutation, as in A.S. _bl[=e]dan_, to bleed, from _bl[=o]d_, blood; and the resulting M.E. _[=e]_ is ALWAYS close, as in _bl[=e]den_ (bl['e]['e]d[*e]n), to bleed.