The inferior maxilla, or the mandible, represents the haemapophyses and the haemal spine. The two halves of which it is composed become very soon confluent in the human subject, but remain longer distinct in the lower Mammalia. The different pieces composing the haemapophysis in the mandible of the turtle or the crocodile may be traced in the single human bone. We recognise the articular bone, or the condyle, and the coronoid, or the process to which is attached the tendon of the temporal muscle. In the fcetal mandible there may be noticed upon the internal surface a thin and distinct plate of bone, which seems to shut in the sockets for the teeth, the splenial. The portion of bone which unites the two rami, and forms the symphysis, is the representative of the dentary bone or the haemal spine.