Duck eggs black inside

[duckincubation]

It's day 9 and I saw veins 2 days ago now I just see a black mass in all of them but I can't make out any veins please help are they ok ?!

 

[sourland]

I would guess that the embryos have developed to the point that the veining is no longer apparent. Good luck for a successful hatch.

 

[duckincubation]

Thank you