Of course variations in the vowel-sounds are also introduced, in the case of strong verbs, by the usual 'gradation' due to their method of conjugation. To meet this difficulty in some measure, numerous (but not exhaustive) cross-references have been introduced, as when, e.g. '~Bar~, bare' is given, with a cross-reference to Beren. Further help in this respect is to be had from the table of 183 strong verbs given at pp. lxix-lxxxi of the Preface to Part I of the Specimens of English (2nd edition); see, in particular, thealphabetical index to the same, at pp. lxxxi, lxxxii. The same Preface further contains some account of the three principal Middle-English dialects (p. xl), and Outlines of the Grammar (p. xlv). It also explains the meaning of the symbols þ, ð (both used for _th_), 3* (used for y initially, gh medially, and gh or z