are broad and strong, especially in the front, where they coalesce with the sides of the body and the root of the odontoid process. They are covered above by the superior articular surfaces. The laminae are thick and strong. They play a large role in the stability of the cervical spine alongside the laminae of C7. The vertebral foramen is large, but smaller than the atlas. The transverse processes are very small, and each ends in a single tubercle. Each process is perforated by the transverse foramen, which is directed obliquely upward and laterally. The superior articular surfaces are round, slightly convex, directed upward and laterally, and are supported on the body, pedicles, and transverse processes. The inferior articular surfaces have the same direction as those of the other cervical vertebrae. The superior vertebral notches are very shallow, and lie behind the articular processes. The inferior vertebral notches lie in front of the articular processes, as in the other cervical vertebrae. The spinous process is large, very strong, deeply channelled on its under surface, and presents a bifurcated extremity. Variation Contact sports are contraindicated for individuals with anomalous dens, as any violent impact may result in a catastrophic injury. This is because a malformed odontoid process may lead to instability between the atlas and axis (the C1 and C2 cervical vertebrae). Development The axis is ossified from five primary and two secondary centres. The body and vertebral arch are ossified in the same manner as the corresponding parts in the other vertebrae, viz., one centre for the body, and two for the vertebral arch. The centres for the arch appear about the seventh or eighth week of fetal life, while the centres for the body appear in about the fourth or fifth month. The dens, or odontoid process, consist originally of a continuation upward of the cartilaginous mass, in which the lower part of the body is formed. During about the sixth month of fetal life, two centres make their appearance in the base of this process: they are placed laterally, and join before birth to form a conical bilobed mass deeply cleft above; the interval between the sides of the cleft and the summit of the process is formed by a wedge-shaped piece of cartilage. The base of the process is separated from the body by a cartilaginous disk, which gradually becomes ossified at its circumference, but remains cartilaginous