EGG TERMINOLOGY

Air Cell-  The empty space between the white and the shell at the large end of the egg. When an egg is first laid, it is warm. As it cools, the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell.

 

Albumen- A combination of the four layers of a watery substance (88% water, 11% protein) that surrounds and contains the yolk within the center of the egg shell.

 

Blastoderm- The collective mass of cells produced by the splitting of a fertilized ovum from which the embryo develops.

 

Blastodisc- The germinal spot on the ovum from which the blastoderm develops after the ovum is fertilized by the sperm.

 

Chalazae- Prolongations of the thick inner-white that are twisted like ropes at each end of the yolk. Their function is to anchor the yolk in the center of the egg shell cavity.

Embryo- A fertilized egg at any stage of development prior to hatching. In its later stages, it clearly resembles the fully developed chick.

 

Shell Membranes-  Inside the shell there are two shell membranes: inner and outer. After the egg is laid and it begins to cool, an air cell forms between these two layers at the large end of the egg.

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

 

Shell -  The egg's outer covering, accounting for about 9 to l2% of its total weight depending on egg size. The shell is the egg's first line of defense against bacterial contamination.

 

Yolk-  A globular mass of yellow, nutritious semi-liquid contained in a transparent membrane (the vitelline membrane) and located in the center of an egg. The yolk is the chick's food during its pre-hatching life and its first food after it emerges from the shell.