CHAP, m.] SKELETON OF THE HEAD AND TRUNK. 49 



14. Having considered the dorsal part of the axial skeleton- 

 the backbone we may now proceed to consider that opposite or 

 ventral structure, the BREASTBONE, together with those parts (the ribs 

 with their cartilages), which connect the backbone and breastbone 

 together. The breastbone and ribs, with the dorsal vertebra to 



Fig. 24. SKELETON OF THE THORAX. 



c. End of xiphoid cartilage. 

 ca. One of the costal cartilages, 

 m. Steruebne of body of sternum. 



a;. Xiphoid process. 



p. Presternum or manubrium. 



which the ribs are dorsally attached, together constitute the skeleton 

 of the tliwax. The thoracic part of the axial skeleton thus forms a 

 sort of bony cage in which, during life, those most important organs, 

 the heart and lungs, are sheltered and protected. 



15. The breastbone, or STERNUM, extends along the ventra 



