This undifferentiated embryonic structure then undergoes a phase of major cell migration called gastrulation, producing a gastrula with three separate germ layers: the endoderm, mesoderm, and ectoderm. Endoderm The endoderm is formed from cells that migrate toward the center of the developing gastrula.
The Eiffel tower is made of puddled iron. It is made up of steel in steel X's. The Eiffel Tower is made of iron. The Eiffel Tower is made of pure iron.
1 The Eiffel Tower is 1,063 feet (324 meters) tall, including the antenna at the top. Without the antenna, it is 984 feet (300 m).  It was the tallest manmade structure until the Chrysler Building was built in New York in 1930.