These are quadrangular, massive, and longer than the vertebræ of other regions; they decrease in length from the second to the last. The =third=, =fourth=, and =fifth= are typical, and have the following characters: 1. The =bodies= are long as compared with those of other vertebræ. Each presents a median =ventral spine= or =crest=, which becomes more prominent as it is traced backward, and is tuberculate at its posterior end. The =lateral aspect= is concave. The =dorsal surface= has a flat central area which is narrow in the middle of the vertebræ, and wide at either end; it gives attachment to the superior common ligament. On either side of this area is a groove which lodges the longitudinal spinal vein. These lateral grooves are connected at the middle of the surface by a transverse furrow, in which there are several foramina through which veins emerge from the spongy substance of the body. The =anterior extremity= presents a head which has an oval articular surface, strongly convex, and wider above than below. The =posterior extremity= is larger and has a nearly circular cotyloid cavity. [Illustration: FIG. 8.—LAST CERVICAL AND FIRST THORACIC VERTEBRÆ OF HORSE, LATERAL VIEW. (After Schmaltz, Atlas d. Anat. d. Pferdes.) ] 2. The =arches= are large and strong. They are perforated on either side by a foramen which communicates with the foramen transversarium. The vertebral notches are large. 3. The =articular processes= are large. Their articular surfaces are extensive, oval in outline, and slightly concave; the anterior ones are directed upward and inward, the posterior downward and outward. The remaining surface is mainly roughened for ligamentous and muscular attachment. A crest connects the articular processes of the same side on the fourth and fifth; on the third it does not reach the anterior process. 4. The =transverse processes= are large and plate-like. Each arises by two roots, one from the arch and one from the body; between these is the =foramen transversarium=, through which the vertebral artery passes. The process divides externally into anterior and posterior branches, which are thickened and rough for muscular attachment. 5. The =spinous process= is represented by a crest (Crista spinosa), which widens behind, and is connected by ridges with the posterior articular processes.