John Linton Myres,
1911 Encyclopædia Britannica, Volume 8…
(1911)
“ Language is no better guide, for it is not clear that the Dorian dialect is that of the most recent conquerors, and not rather that of the conquered Achaean inhabitants of southern Greece; in any case it presents no such affinities with any non-Hellenic speech as would serve to trace its origin. Even in northern and west-central Greece, all vestige of any former prevalence has been obliterated by the spread of “Aeolic” dialects akin to those of Thessaly and Boeotia ”

