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.
Eiffel Tower History. The Eiffel Tower was built for the International Exhibition of Paris of 1889 commemorating the centenary of the French Revolution. The Prince of Wales, later King Edward VII of England, opened the tower. Of the 700 proposals submitted in a design competition, Gustave Eiffel 's was unanimously chosen. However it was not accepted by all at first, and a petition of 300 names-including those of Maupassant, Emile Zola, Charles Garnier (architect of the Op ra Garnier), and Dumas the Younger-protested its construction.