154 ANTHROPOLOGY. 



Ä. External Ear. 



The external ear, or auricle, is situated at the side of the head : it consists 

 of the auricle or pinna and the external meatus, which terminates at and is 

 closed by the tympaum. 



The Pinna, or Auricle, commonly termed the ear, is the external portion, 

 composed of cartilage, ligament, and a few muscular fibres, the whole 

 inclosed in a duplicature of the skin. It is convex towards the head, and 

 concave externally, in which aspect it presents various irregularities, all 

 tending towards the meatus. The convex border which forms the outline 

 ♦f the ear is called the helix ; superiorly this edge is thin, and curled out- 

 wards so as to bound a depression named the fossa innominata ; anteriorly 

 it bends downwards and backwards into the concha and above the meatus- 

 Anterior and inferior to the helix is the semicircular prominence called the 

 antihelix. This is narrow and prominent behind ; as it ascends it becomes 

 broader, retires from the surface, and divides into two crura, which run in 

 beneath the edge of the helix ; this depression between its crura is named 

 the scaphoid or navicular fossa. Anterior to and overhanging the meatus 

 auditorius, somewhat like a valve, is the eminence called tragus^ of a triangu- 

 lar form. The free apex of this is directed towards the concha, and the 

 inner surface is beset with strong coarse hairs or vibrillae, which extend 

 across the orifice of the meatus. When pressed backwards or inwards, the 

 tragus can cover the meatus. Opposite to the tragus and separated from it 

 by a deep round notch is the antitragus^ a small tubercle connected with the 

 lower extremity of the antihelix. Within the antihelix, tragus, and antitra- 

 gus, and traversed above by the helix, is the large and deep depression 

 called the concha, into which all the other grooves converge ; it leads 

 directly downwards into the meatus. The lower pendulous part of the 

 auricle is called the lobe, and contains none of the cartilage which constitutes 

 the skeleton of the rest of the ear. 



The ligaments of the auricle are the anterior, from the root of the zygoma 

 to the anterior part of the helix, and to the tragus ; and the posterior, from 

 the mastoid process of the concha. 



Of the muscles of the external ear we have already considered those which 

 move it on the head (anterior or attrahens, superior or attollens, and the 

 posterior or retrahens). The intrinsic muscles, or those which only pass 

 from one part of the cartilage to the other, are named from the eminences 

 to which they are attached. They are the major and minor helices, the 

 tragicus, anti-tragicus, and transversus auricularis. These muscles, though 

 only rudimentary in man, are highly developed in some of the inferior 

 animals. 



Meatus auditorius externus is a tube leading from the concha to the 

 membrana tympani ; it is about an inch and a quarter long, with the exter- 

 nal half of cartilage, the remainder of bone. By drawing the auricle 

 upwards and backwards we can partly straighten the canal, and, with a 

 strong light directed in it, we can see down to the membrana tympani. 

 The bon}'^ portion of the meatus is wanting in the child, its place being 

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