Interior view of a bird's egg: hard, porous shell enclosing an embryo and the substances that nourish it during incubation.
Shell: hard crust covering and protecting the egg.
Developing embryo: small pocket related to the germ.
Air space: part of the egg containing only air.
Vitellus or yolk: part of the egg which develops into an embryo once the egg has been fertilized.
Albumen or white: white of the egg, which nourishes the embryo once the egg has been fertilized.
Amniotic liquid: liquid substance in the amnion.
Embryo: bird which has not yet hatched.
Allantoic fluid: one of three extensions of a bird embryo.
Shell membrane: membrane on the inside of the shell.
Chalaza: part of the white of the egg.