Twenty four Newzeland White Rabbits, divided into 2 groups comprising 5.5 months and 1.5 years old. Each group consisting of 6 male and 6 female. In each sex group 3 rabbits were used for macroscopic and the other 3 for microscopic studies. Total and regional length of the vertebral column, spinal cord, the termination of the spinal cord within the vertebral canal, allometric growth rate of the spinal cord in relation to the vertebral column, transverse and vertical diameters of the spinal cord, central canal of the spinal cord and the ratio between gray and white matter of the spinal cord were studied the results were statistically analyzed and are appeared in the result section.
)