THE SKELETON. 



2 3 



are those not elongated and with no medullary cavity: 

 tarsus and carpus. Flat bones are plate-like, with a layer- 

 of cancellous tissue between two layers 

 of compact tissue : parietal, scapula, 

 and innominate. Irregular bones are 

 those which have an exceedingly ir- 

 regular shape : ethmoid and vertebrae. 

 The aspect of a bone is the portion 

 seen when viewed from a given direc- 

 tion. The bQrder of a bone is the 

 margin, edge, or ridge at the juncture 

 of two surfaces. Proximal is used to 

 designate the portion of a structure 

 nearer the axis or spinal column, in 

 distinction to distal, which signifies the 

 part farther removed from the axis. 

 Cranial indicates the part of an organ 

 nearer to the plane passing just beyond 

 the head and perpendicular to the spinal 

 axis, while caudal is applied to the 

 other part of the organ nearer to the 

 perpendicular plane at the end of the 

 extended tail. 



Sagittal refers to the plane bisecting 

 the animal in a vertical and longitudi- 

 nal direction. Medial and lateral are 

 adjectives, the former meaning nearer 

 to the sagittal plane and the latter more 

 remote on either side of that plane. 

 Proximad, distad, craniad, caudad, 

 mediad and laterad are adverbs indicating direction in ac- 

 cordance with the adjectives to which they are related. 



A process is projection or elevation. 



A tuberosity is a rough obtuse process. 



FIG. 12. LONGITU- 

 ' DINAL SECTION OF 

 THE HUMERUS OF A 

 KITTEN. 



h, Epiphysis for head ; 

 c, cartilage ; b, bone ; 

 m, medullary sub- 

 stance; o, epiphysis 

 for olecranon proc- 

 ess. 



