Notogenesis is the process of formation of notochord. Notochord is a flexible rod made of a material similar to cartilage. It is formed by following ways:
1) Notochord is developed from the mesoderm. So, it is mesodermal in origin.
2) After formation of three germinal layers, meso-ectodermal cells lying in the mid-dorsal region of the roof of the archenteron separate from other mesodermal cells.
3) They form a solid, cylindrical rod like structure which is the beginning of the notochord formation.
4) The thin membrane develops aroundrod-like structure known as notochordal sheath.
5) The outer layer of this sheath is elastic and inner somewhat rigid with abundant fibers.
6) Finally rod-like structure and notochord sheath form the notochord.
7) Notochord lies parallel to and just below the neural tube.
8) It develops into vertebral column as well as other skeleton in the course of development.