Membranes

Shell Membranes:

Just inside the shell are two shell membranes, inner and outer. After the egg is laid and begins to cool, at the large end of the egg, an air cell forms between these two membranes.

Vitelline Membrane:

The strength of this yolk covering protects the yolk from breaking. The vitelline membrane is weakest at the germinal disc and tends to become more fragile as the egg ages.

– See Air Cell, Composition, Formation, Germinal Disc, Grading