268 ZOOTOMV. 



skeleton as spaces between the peduncles of successive 

 neural arches ; they serve for the transmission of the spinal 

 nerves. 



V. Make out, in the ribs and sternum : 



29. The seven true ribs : each consists of a completely 

 ossified vertebral rib dorsally, and of a cartilaginous 

 sternal rib ventrally. The vertebral rib has a head 

 articulating with the capitular facet on the centrum of its 

 own vertebra and of that next in front a tubercle on the 

 dorsal side articulating with the tubercular facet on the 

 transverse process of its own vertebra, and a short dorsal 

 process just external to the tubercle. The sternal ribs, 

 with the exception of the first, sixth, and seventh, articulate 

 at the junction of two of the segments of the sternum. 



30. The five false ribs : in all but the first of these the 

 tubercle is obsolete, and in all the sternal rib does not 

 articulate directly with the sternum. 



31. The sternum, consisting of six segments, the 

 so-called sternebrae, of which the first is large, and keeled 

 ventrally, and is called the manubrium. With the sixth is 

 connected a rounded plate of cartilage, the xiphisternum 

 or xiphoid process. 



VI. In the skull note : 



32. The large development of the facial as compared 

 with the cranial portion of the skull, the latter including 

 those bones which surround the brain-case. 



33. The large foramen magnum, on the posterior 

 surface of the brain-case, through which the spinal cord 

 becomes continuous with the brain. 



34. The two oval occipital condyles, bounding the 

 foramen magnum at the sides and below. 



35. The large hollow on each side of the skull formed 

 mainly by the orbit or cavity for the eye, and bounded 



