260 VERTEBRATE ZOOLOGY 



The body, thus prepared, should be boiled until the bones can 

 be thoroughly cleaned. It is well while doing this to disarticulate 

 the head and the hind limbs from the remainder of the skeleton. 

 Do not, however, boil the bones until the ligaments are destroyed 

 and the bones fall apart. It is also well to pass a string through 

 the neural canal as soon as the spinal cord is destroyed, and tie 

 the two ends together so as not to lose the sequence of the verte- 

 brae, and to number the ribs. 



The Appendicular Skeleton. The anterior extremities are made 

 up of the pectoral girdle and the forelegs. The pectoral girdle 

 is a paired structure, which in most land vertebrates is made up, 

 on each side, of the scapula, coracoid, and procoracoid, or clavicle. 

 In the cat it is incomplete, the dorsal element, the scapula, 

 being the only one which is well represented. This is a flat, tri- 

 angular bone, which lies between the muscles and the ribs near 

 the anterior end of the thorax, on each side. Projecting from the 

 middle of the lateral surface is a flat ridge called the spine of the 

 scapula, which divides this surface into two areas, the supra- 

 spinous fossa, lying anterior to the spine, and the infraspinous 

 fossa, lying posterior to the spine. Ventrally the spine bears two 

 processes: the acromion process, near the ventral end, and the 

 metacromion process, dorsal to it. At the ventral end of the scap- 

 ula is a depression called the glenoid fossa, in which the humerus 

 articulates. Near the anterior end of this fossa is a curved pro- 

 jection, the coracoid process, which is homologous to the coracoid 

 bone of the lower vertebrates. 



Besides the scapula the pectoral girdle contains, on each side, 

 the clavicle. This is a small curved bone, which lies embedded in 

 the muscles of the shoulder. It does not articulate with any other 

 bone, but is joined with the acromion process by a ligament. 



Exercise 48. Draw the lateral side of the scapula. 



The skeleton of the foreleg is made up of three divisions: a 

 proximal, a middle, and a distal division. The proximal division 

 is formed of the humerus, a large cylindrical bone. At its upper 

 end are the head of the humerus, by which it articulates with the 

 scapula, and two prominences, of which the outer one is the greater 



