cells begin to mature, with different cells at
different stages at any given time. Full
maturation takes about ten weeks. During the
tenth, the germ cell rapidly accumulates
yellow yolk, mostly fats and proteins, which
is synthesized in the hen’s liver. Its color
depends on the pigments in the hen’s feed; a
diet rich in corn or alfalfa makes a deeper
yellow. If the hen feeds only once or twice a
day, her yolk will show distinct layers of dark
and light. In the end, the yolk comes to dwarf
the germ cell, containing as it must the
provisions for 21 days during which the chick
will develop on its own.
Making the White The rest of the egg
provides both nourishment and protective
housing for the germ cell. Its construction
takes about 25 hours and begins when the
ovary releases the completed yolk. The yolk is
then gripped by the funnel-shaped opening of
the oviduct, a tube 2–3 feet/0.6–0.9 meter