2 - AIR CELL Pocket of air formed at large end of egg caused by contraction of the contents during cooling after laying. Increases in size as egg ages.

3 - SHELL MEMBRANES Two membranes - inner and outer shell membranes - surround the albumen. Provide protective barrier against bacterial penetration. Air cell forms between these two membranes.

4 - THIN ALBUMEN (WHITE) Nearest to the shell. Spreads around thick white of high-quality egg.

5 - THICK ALBUMEN (WHITE) Major source of egg riboflavin and protein. Stands higher and spreads less than thin white in higher-grade eggs. Thins and becoomes indistinguishable from thin white in lower-grade eggs.

6 - CHALAZAE Twisted, cord-like strands of egg white. Anchor yolk in center of egg. Prominent chalazae indicate freshness.

7 - VITELLINE (YOLK) MEMBRANE Closer seal which holds egg yolk.

8 - GERMINAL DISC

9 - YOLK Yellow portion of egg. Color varies with feed of the hen, but doesn't indicate nutritive content. Major source of egg vitamins, minerals and fat and about half of the protein.