English: This diagram depicts a cross section of a vertebrate embryo in the neurula stage. This stage is characterized by development of the nervous system through the formation of the neural tube. The neural tube later develops into the brain and the spinal cord. The other structures in the diagram also play major roles in development. The notochord functions as a dorsal supporting rod until it is replaced by the vertebral column. The somites become the vertebral column and the skeletal muscles. When internal organs develop, they are located in the coelom.