THE I:\TI: i:\.\i. i:.n; 847 



plate, placed at the lower part of the conchal plate, intermediate between 

 it and the auditory canal. The internal integumentary membrane, with some 

 yellow clastic fasciculi, unite this cartilage to the other two portions 

 l>< tut i n uhirh it is situated. Its relations with these are such, that it 

 receives within its lower border the bony circular prominence forming tho 

 margin of tho auditory hiatus, while it may itself be received into the in- 

 fim<libuliform canal of the conchal cartilage an arrangement resembling 

 the tubes of a telescope. 



3. SCUTIFOKM CARTILAGE. This is a small cartilaginous plate, situated 

 in front of the base of the concha, at the surface of the temporal muscle ; it 

 is irregularly triangular, is attached to the conchal cartilage by some 

 muscular fasciculi, and transmits to that cartilage tho action of some other 

 muscles which are fixed on the cranial bones. 



(The arteries of the concha proceed from branches of the external carotid, 

 and the veins pass to a trunk of the same name ; the nerves are divisions 

 of the facial and the first cervical pair.) 



2. Muscles of the External Ear. 



There are found, on the surface of the concha, within and without, some 

 fleshy fibres, which are veritable intrinsic muscles. But the slight importance 

 of these induces us to pass them over, in order to study exclusively the 

 extrinsic muscles, which move the conchal apparatus. These are ten i^ 

 number : in the first layer are the zygomatico-auricularis, temporo-auricularis 

 i. it- rnus, scuto-auricularis externus, three cervico-auriculares, and the parotido- 

 auricularis ; in the second layer, the temporo-auricularis internus, scuto- 

 aiirii-iilaris internus, and the mastoido-auricularis. 



1. ZYGOMATICO-AUBICULABIS (attolens anterior Percivall ; temporo- 

 auricularis Leyh. Figs. 110, 5 ; 396). This muscle is generally composed 

 of two fleshy bands joined by cellular tissue, and rising from the zygomatic 

 process of the temporal bone by means of an apoueurosis common to it 

 and the orbicularis palpebne. The inferior of these two bands is inserted 

 to the outside of the base of the concha, its fibres mixing with those of the 

 parotido-auricularis; the superior band terminates on the outer border of 

 the scutiform cartilage. 



Placed immediately beneath the skin, this muscle partly covers the 

 superior extremity of the parotid gland, and the zygomatic process. 

 It draws the ear forward. 



2. TEMPOBO-ACBICCLAUIS EXTEBNTJS (attolens maximus Percivall. Figs. 

 110, 1 ; 396). A very thin, wide muscle, covered by the skin, lying on the 

 temporal muscle, united posteriorly to the superior cervico-auricularis, in 

 front and outwardly to the zygomatico-auricularis. It arises from the 

 whole of the parietal crest or ridge, 1 mixing in its upper half or third with 

 the muscle of the opposite side ; it terminates, by one portion, on the inner 

 margin of the Bcutiform cartilage, and by another, on the inner side of 

 the conchal cartilage, by means of a thin fascia that covers part of the 

 former cartilage and the external scuto-auricularis. 



It acts as an adductor of the concha, drawing it inwards ; it also carries 

 it forwards, and concurs in making it pivot on itself, so as to bring the 

 opening of the ear forward. (In tho Ox, the common muscles of the ear do 



1 Owing to this crest bordering tin- temporal fossa, ft Irani has thought proper to give 

 to the two muscles of the ear attached tlx r< to, the name of temporo-auricularea ; but it 



\vi.nlil IN- more upim-prat.- ! ! ML" :'( tin-in tin- j.nriit 



