If it is some of his inner parts...which it appears to be....I would not give him hope. However I would leave it in the bator and time will tell if the chick will live or not. my 2 cents.
found one older post that looked like the same thing but no end report-some thought it might be an undeveloped twin. It has a little base to it. Really odd-it is the last chick so the bator is a nice safe place to wait it out! I hope it is ok and it dries up.