from what they knew. Comparative linguistics led to a picture of ancient Greek that more or less corroborated Erasmus' view, though with some modifications. It soon became clear, for instance, that the pattern of long and short vowels observed in Greek was mirrored in similar oppositions in other languages and thus had to be a common inheritance (see Ablaut); that Greek had to have been at some stage because it regularly corresponded to in all other Indo-European languages (cf. Gr. : Lat. ); that many instances of had earlier been (cf. Gr. : Lat. ); that Greek sometimes stood in words that had been lengthened from and therefore must have been pronounced at some stage (the same holds analogically for and , which must have been ), and so on. For the consonants, historical linguistics established the originally plosive nature of both the aspirates and the mediae , which were recognised to be a direct continuation of similar sounds in Indo-European (reconstructed and ). It was also recognised that the word-initial spiritus asper was most often a reflex of earlier (cf. Gr. : Lat. ), which was believed to have been weakened to in pronunciation. Work was also done reconstructing the linguistic background to the rules of ancient Greek versification, especially in Homer, which shed important light on the phonology regarding syllable structure and accent. Scholars also described and explained the regularities in the development of consonants and vowels under processes of assimilation, reduplication, compensatory lengthening etc. While comparative linguistics could in this way firmly establish that a certain source state, roughly along the Erasmian model, had once obtained, and that significant changes had to have occurred later, during the development towards Modern Greek, the comparative method had less to say about the question when these changes took place. Erasmus had been eager to find a pronunciation system that corresponded most closely to the written letters, and it was now natural to assume that the reconstructed sound system was that which obtained at the time when Greek orthography was in its formative period. For a time, it was taken for granted that this would also have been the pronunciation valid for all the period of classical literature. However, it was perfectly possible that the pronunciation of the living language had begun to move on from that reconstructed system towards that of Modern Greek, possibly already quite early during antiquity. In