THE EXTERNAL EAR. 435 



does not correspond with the observations of subsequent anato- 

 mists, as the matter appears fibrous. 



The external ear is united to the side of the head by three li- 

 gaments. The anterior arises from the root of the zygomatic 

 process above the articulation of the lower jaw, and is inserted 

 into the pointed production of cartilage on the fore part of the 

 helix. The posterior arises from the swell of the temporal bone, 

 which runs into the front margin of the base of the mastoid pro- 

 cess, and is inserted into the convex side of the concha, at the 

 beginning of the meatus auditorius. The superior arises from 

 the temporal aponeurosis, and is inserted into the upper part of 

 the concha. These ligaments lie immediately below the mus- 

 cles destined to move the ear. 



The Meatus Auditorius Externus, is, in the adult, an inch in 

 length, reckoning from its external orifice to the membrane of 

 the tympanum, which closes it inwardly. It is about three lines 

 in diameter, is ratheroval than cylindrical, and somewhat smaller 

 in the middle than at either of its extremities. It runs inwards, 

 with a slight inclination forwards; the exterior half is formed 

 by the cartilage of the pinna, and the internal half by the tem- 

 poral bone: it departs from the horizontal course, in being 

 curved at its middle where the two sections join. This curva- 

 ture has its convexity upwards, so that when we wish to look to 

 the bottom of the canal, the external ear must be pulled upwards 

 and backwards. 



The cartilaginous portion of the meatus auditorius is formed 

 by a triangular piece springing from the base of the tragus and 

 from the inferior anterior part of the concha. This portion is 

 nearly a tube, but is interrupted above and behind by the inter- 

 vention of a dense fibrous tissue, continuous with, and indeed 

 the same with that which joins the helix and the tragus. The 

 internal margin of the cartilaginous meatus forms a point be- 

 low; and adheres closely by ligament to the asperities on the 

 margin of the bony meatus. If there were no fissures in the ex- 

 ternal ear, it would, therefore, be almost immoveable. 



The skin covering the external ear is more delicate than in 

 most other parts of the surface of the body. Its sebaceous 



