ELEMENTS OF MAMMALIAN ANATOMY. 



femur, fibula, metacarpals, and phalanges. Short bones 

 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 ex- 

 ceedingly irregular shape: ethmoid 

 and vertebrae. The aspect of a bone 

 is the portion seen when viewed from 

 a given direction. The border of a 

 bone is the margin, edge, or ridge at 

 the juncture of two surfaces. Proxi- 

 mal 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. Cephalic indicates the 

 part of an organ nearer to the plane 

 passing just beyond the head and per- 

 pendicular 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 longitu- 

 dinal direction. Mesal 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, cephalad, 

 caudad, mesad, and later ad are adverbs 



indicating direction in accordance with the adjectives to 

 which they are related. 







FIG. 12. - - LONGITU- 

 DINAL SECTION OF 

 THE HUMERUS OP A 

 KITTEN. 



li, Epiphysis for head; 

 c, cartilage ; b, bone ; 

 m, medullary sub- 

 stance; o, epiphysis 

 for olecranon pro- 

 cess. 



