376 



THE ANATOMY OF THE HORSE 



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

 (see page 348). 



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

 which there are the spine, the coracoid process, and the glenoid cavity. 



The FOSS.E are two externally, (a) the anterior, and (b) the posterior 

 fossa, diAdded by the spine (^^ 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 scapulae (belly of the scapula), in the same 

 way subserves the use of the subscapularis. 



1. Spine. 



2. Coracoid process. 



3. Glenoid cavity, 

 a. Anterior fossa. 



-Outer Surface of Left Scapula- 

 6. Posterior fossa. 



iperior costa, to which the cartilage ie 

 attached. 



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

 cartilage, which increases the length of the blade. The anterior border is 

 thin, while the posterior is comparatively thick. 



Tee 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 op 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 

 broad it may always be predicted that the hunter will be powerless in using 

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

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

 such will not be the case. Heavy 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 

 the horae at i)age 107. 



