72 SURGICAL APPLIED A. \ATOMY. tcha r . v 



meatus is formed of bone. The rest is cartilaginous. 

 In a child of five or six years of age the bony and car- 

 tilaginous portions of the meatus are about of the 

 same length (Symington). The meatus is relatively 

 as long in a child as it is in an adult. The narrowest 

 portion of the meatus is about its middle. The outer 

 orifice is elliptical, with its greatest diameter directed 

 from above downwards ; therefore specula should be 

 elliptical in shape rather than round. The inner end 

 of the tube, on the other hand, is slightly wider in 

 the transverse direction. Owing to the obliquity of 

 the membrana tympani, the floor of the meatus is 

 longer than the roof. The cartilaginous segment of 

 the tube presents many sebaceous glands that may be 

 the seat of minute and very painful abscesses. It 

 also presents numerous ceruminous glands, which 

 secrete the cerumen of the ear, and which, when their 

 secretion is excessive, may produce the plugs of wax 

 that often block the meatus. Lacerated wounds of 

 the cartilaginous meatus are apt to bleed freely, ow- 

 ing to the difficulty with which the vessels bound up 

 with the cartilage contract. In the floor of this part 

 of the meatus are certain fissures, fissures of San- 

 torini. They are filled up with fibrous tissue. They 

 permit of easier movement of the cartilaginous meatus. 

 It is through these gaps in the cartilage that a parotid 

 abscess may burst into the meatus. There are neither 

 hairs nor glands in the lining of the bony part of the 

 tube. 



The skin of the meatus, when inflamed, may pro- 

 duce an extensive muco-purulent discharge, obitis 

 externa. Polypi are apt to grow from the soft parts 

 of the canal, and exo.stoses from its bony wall. 

 Foreign bodies are frequently lodged in the meatus, 

 and often involve great difficulties in their extraction. 

 It would appear that in many cases more damage is 

 4one by the surgeon than by the intruding substance. 



