what is notochord??n in which part spinal cord is enclosed??
The notochord is a flexible rod-shaped body found in embryos of all chordates. It is composed of cells derived from the mesoderm and defines the primitive axis of the embryo. In some chordates, it persists throughout life as the main axial support of the body, while in most vertebrates it becomes the vertebral body of the vertebral column.The notochord is found ventral to the neural tube. It is like the the first "backbones" serving as support structures in the primitive chordates