αυξανομενος δε ο κροκόδειλος γίγνεται και εἰς επτακαιδεκα πηκεις και μείζων έτι
This is my first time doing this so I apologise if I do anything wrong >.> And sorry about the accents, I tried to put them on but they went weird.
It's the last part I don't understand, what purpose does the εἰς serve?
I'm not too certain about context either because my translation's a bit rough, what's just happened I think is that the narrator of the story has just compared the crocodile's egg to being that of a goose's saying that it begins small but grows up to be huge.
Thank you!