122 THE SURGICAL ANATOMY OF THE HORSE 



Particular care should be taken in dealing with the inferior and 

 posterior aspects of the ball on account of the numerous vessels 

 placed on the floor and back of the orbit, among which may be 

 mentioned the ophthalmic artery and its branches, and the orbital 

 branch of the superior dental artery. 



Subsequent treatment depends upon whether it is intended to 

 insert an artificial eye or not. If such a procedure is not intended 

 the cavity should be packed with absorbent material saturated with 

 antiseptic solution, which should be kept in position by suturing the 

 eyelids — a single suture being quite sufficient. This packing should 

 be left in position for two or three days, when a fresh one is introduced, 

 and this process should be repeated until there is no trace of 

 discharge visible on the plug. The eyelashes should now be clipped 

 off, and the edges of the eyelids scraped until raw. The lids are 

 then sutured together by means of a number of closely inserted 

 interrupted sutures. 



THE EXTERNAL EAR 



The parts of the external ear are the conchal, annular, and scutiform 

 cartilages, the tube-like auditory process of the petrous temporal 

 bone, the muscles which move the cartilages, or attach them to 

 the head or to one another, and the nerves and vessels which supply 

 these structures. 



The Cartilages. — T/ie concha/ cartilage is usually referred to as 

 resembling a trumpet in shape. The tube-like portion is dilated 

 near its upper extremity, but inferiorly it becomes much narrower 

 and embraces the annular cartilage. 



The opening of the trumpet approaches the elliptical in outline, 

 and presents superior and inferior commissures where its edges meet 

 one another. This cartilage is attached to the guttural pouch by a 

 fibrous prolongation over the outer aspect of the scutiform. 



