Eggs

We have birds. Our birds had sex. Lots of times. Anyway, thats not the point. The point is, they had eggs. Momma bird sat on the eggs for weeks. Gestation was supposed to be 18 days. Now, four of her five eggs have turned gray, and she has given up on sitting on them.

Veev and I were talking about what is inside the eggs. If we cracked one open, would we get a partially developed bird? Egg yolk? Something completely different?

Any ideas?