376 THE ANATU-MY (Jb' TilK llUitsE 



apex looking downwards and forwards, and its base upwards and backwards 

 (see page 348). 



It presents three fossae, tliree borders, and three angles ; in addition to 

 which there are the spine, the coracoid process, and the glenoid ca\ ity. 



The FOSSiE are two externally, (a) the anterior, and (b) the posterior 

 fossa, divided by the spine (j_ Fig. 23). These lodge and give attachment to 

 the fibres of the supra and infra-spinatus muscles, while the internal fossa, 

 sometimes called the venter scapuhe (belly of the scapula), in the same 

 way subserves the use of the subscupularis. 



Fio. 23.— Outer Surface ok Left .Scapula. 



1. Spine. h- Posterior fossil. 



2. Coracoid process. c.Siiperior costa, to which the cartilage ia 

 8. Glenoid cavity. attached. 



a. Anterior fossa. 



The superior border is rough for the attachment of the broad strip of 

 cartilage, wliich increases the leugtli of the blade. The anterior border is 

 thin, while the posterior is compai'atively thick. 



The two superior angles present nothing very remarkable, but the 

 inferior is occupied by the coracoid process anteriorly, and by the glenoid 

 cavity posteriorly — which latter is a smooth oval cavity, lined with cartilage. 

 It receives the head of the humerus. 



On account of the important offices belonging to the muscles which 

 occupy the fossae on this bone, and since it is found that in proportion to 

 the extent of the latter will be the muscular power, horsemen examine with 

 great care the due development of the scapula. Unless it is long and 

 bi'oad it may alway.s be predicted that the hunter will be powerless in using 

 his fore-legs "in dirt," or in getting out of other dilliculties ; and though 

 some hacks with short shoulders may go well euougli, yet, in the majority, 

 such will not be the case. Heavj^ draught-horses, in which a great thickness 

 of muscle is heaped upon the blade, are not so dependent upon its length 

 and breadth, as has been already .shown in treating of the external form of 

 (lie horse at page 107. 



