chnp.v.j THE EAR. 73 



Mason reports three cases where a piece of slate-pencil, 

 a cherry-stone, and a piece of cedar-wood were lodged 

 in the canal for respectively forty years, sixty years, 

 and thirty years. 



The upper wall of the meatus is in relation 

 with the cranial cavity, from which it is only 

 separated by a dense layer of bone. Thus, abscess or 

 bone disease in this part may possibly lead to menin- 

 gitis. A case is reported where an inflammation of 

 the cerebral membrane followed upon the retention of 

 a bean within the meatus. The anterior wall of the 

 canal is in relation with the temporo-maxillary joint 

 and with part of the parotid gland. This may serve 

 in one way to explain the pain often felt in moving 

 the jaw when the meatus is inflamed, although, at the 

 same time, it must be remembered that movement of 

 the lower maxilla produces a movement in the carti- 

 laginous meatus, and that both the canal and the joint 

 are supplied by the same nerve (the auriculo-temporal). 

 From its relation to the condyle of the jaw, it follows 

 that this wall of the meatus has been fractured by 

 that condyle in falls upon the chin. Tillaux states 

 that abscess in the parotid gland may spread into the 

 meatus through the anterior wall of the passage. 

 The posterior wall separates the meatus from the 

 mastoid cells, and through this partition inflammation 

 may extend from one part to the other, especially as 

 the cartilage of the tube is deficient at its upper and 

 posterior parts. Directly behind the posterior wall 

 is the lateral sinus. The inferior wall of the bony 

 meatus is very dense and substantial, and corresponds 

 to the vaginal and styloid processes. 



Blood supply. The pinna and external meatus 

 are well supplied with blood by the temporal and 

 posterior auricular arteries, the meatus receiving also 

 a branch from the internal maxillary. In spite of 

 this supply, the pinna is frequently the seat of 



