The purpose of the present brief note is twofold: to correct in certain respects the analysis outlined in my recent note in MLN 71.265–9 (1956), while taking account of the relative spate, of late, of published views on this subject; and to carry the analysis a bit farther.
1. Sehrt, in Festgabe für Theodor Frings 1-11 (1956), has recently argued the old interpretation, which may be summarized as follows (3): 'Dass also die Zeichen ai, au zwei Lautwerte haben, wird wohl kaum zu bestreiten sein.' I see nothing especially fresh in his arguments for a dual interpretation. His reasoning is based entirely on etymological or morphophonemic considerations or on explicit inattention to dialect provenience. Penzl long ago disposed of such arguments, in JEGP 49.228-30 (1950). The main problem outstanding for Sehrt seems to be the decision between a diphthongal or monophthongal, long or short interpretation of supposed older long diphthongs. Again, Sehrt's arguments are all etymological and morphophonemic. Moreover, his solution is a variation on an old theme; for a handy reference to earlier notions on a 'Hiatusgesetz', see Penzl 227 fn. 41.