ANATOMY OF THE CAT. 



THE SKELETON OF THE CAT. 



The skeleton of the cat consists of 230 to 247 bones ex- 

 clusive of the sesamoid bones (44) and the chevron bones (8). 

 These are divided as follows: head 35-40, vertebral column 

 52-53, ribs 26, sternum 1-8, pelvis 2-8, upper extremities 62, 

 lower extremities 54-56. The number of bones varies with 

 the age of the individual, being fewer in the old than in the 

 young animal, owing to the fact that in an old animal some 

 bones that were originally separate have united. 



I. THE VERTEBRAL COLUMN. COLUMNA VERTEBRALIS. 



The vertebral column, spinal column, or back-bone, consists 

 of a varying number of separate bones, the vertebrae. At its 

 cranial end are seven vertebra (cervical, Fig. i, c) which are 

 without ribs and support the head ; caudad of these are thirteen 

 rib- bearing vertebrae (thoracic, Fig. i, w) ; caudad of these are 

 seven that are again without ribs (lumbar. Fig. 1,0); these 

 are followed by three vertebrse (sacral. Fig. i, .r) which are 

 united into a single bone, the sacrum, which supports the 

 pelvic arch. Following the sacral vertebrae are twenty-two 

 or twenty-three small ribless vertebras which support the tail 

 (caudal. Fig. i, y). 



Thoracic Vertebrae. Vertebrae thoracales (Fig. 4). — The 

 thoracic vertebrae are most typical, and the fourth one of these 

 may therefore be first described (Figs. 2 and 3). It forms an 

 oval ring which has numerous processes and surrounds an 

 opening which is the vertebral foramen («). The ventral one- 



