visual component in every sector of the ancient world. The 
steady increase of stress on retinal impression from the Greek 
into the Roman time has been noted by John Hollander in The  
Untuning of the Sky  (p. 7):

          But with the exception of oral, pre-literary poetry, 
     added complications to the consideration of poetry as 
     sound arise in the existence and use of written languages. 
     If a poem is to be treated as a highly complex utterance 
     in a spoken language, its written form becomes a simple 
     coding of it, word by word, onto a page. The poem will 
     thus be defined in terms of patterns of sound classes. 
     But starting as early as the first Latin use of Greek 
     metres, literary analysis has been confronted with poems 
     whose written versions, or codings, contain significant 
     individual and conventional elements which do not appear