I believe it is a deictic iota added for emphasis. So the word is just εἶτα.http://condor.wesleyan.edu/courses/2006 ... iciota.htm
And I believe that the accent movement is overdetermined: 1) Deictic iota always takes the accent and 2) εἰσι is enclitic. And I guess it always is a grave which makes for a rare situation accent wise.
Thanks, pster. However, what is the meaning of εἶτα here? Smyth in 2653 notes it is used in questions
to introduce surprise, irony, indignation and such, but I don't see anything in here that would merit
inserting εἶτα or its (apparently undocumented in any Greek text I've searched) deictic "relative" εἰτί.
Also, though I'm not sure about accentuation rules and there may be some dispute among scholars
regarding this, but how can εἰσί throw its accent over a non-enclitic εἰτί to ποῖοι?
I know that would happen in a series of enclitics but here it should be ποῖοι εἰτί εἰσιν οἱ κάλαμοι;