The =canine= is a large pointed tooth, slightly recurved and with a long tapering root. The =premolars= are four in number, and in all the cingulum is fairly well seen. The first is a very small tooth with a single tapering root, the second and third are larger and have two roots, while the fourth, the =carnassial=, is much the largest and has three roots. Each of the second, third and fourth premolars has a stout blade, the middle portion of which is drawn out into a prominent cone; the posterior part of the fourth premolar forms a compressed ridge, and at the antero-internal edge of the tooth there is a small inner tubercle. The two =molar= teeth are of very unequal size. The first, which has two anterior roots and one posterior, is wider than it is long, its outer portion being produced into two prominent cusps, while its inner portion is depressed. The second molar is a small tooth resembling the first in its general appearance, but with much smaller outer cusps. =Teeth of the lower jaw.= The three =incisors= of the lower jaw have much the same character as the first two of the upper jaw; while the =canine= is identical in character with that of the upper jaw. The four =premolars= gradually increase in size from the first to the last, but none are very large. The first premolar is a single-rooted tooth resembling that of the upper jaw; the second, third and fourth are two-rooted, like the second and third of the upper jaw, which they closely resemble in other respects. The first =molar= forms the =carnassial= (fig. 84, V), and with the exception of the canine, is much the largest tooth of the lower jaw; it is a two-rooted tooth, with a long compressed bilobed blade, and a posterior tuberculated talon or heel. The second molar is much smaller, though likewise two-rooted, while the third molar is very small and has only a single root. All the teeth except the molars are preceded in the young animal by temporary =milk teeth=. These milk teeth, though smaller, are very similar to the permanent teeth by which they are ultimately replaced. II. ENDOSKELETON. 1. THE AXIAL SKELETON. This includes the vertebral column, the skull, and the ribs and sternum. A. THE VERTEBRAL COLUMN. This consists of a series of about forty vertebrae arranged in succession so that their centra form a continuous rod, and their neural arches a continuous tube, surrounding a cavity, the =neural canal=. The vertebrae may be readily divided into five groups:-- 1. The =cervical= or neck vertebrae. 2. The =thoracic= or chest vertebrae which bear ribs. 3. The =lumbar= vertebrae which are large and ribless. 4. The =sacral= vertebrae which are fused with one another and united with the pelvis. 5. The =caudal= or tail vertebrae which are small. Except in the sacral region the vertebrae are movably articulated to one another, while their centra are separated from one another by cartilaginous =intervertebral discs=. GENERAL CHARACTERS OF A VERTEBRA.