HEAD AND NECK OF THE HORSE 47 



same level as the auriculo-palpebral but from the opposite side of the nerve 

 trunk. It accompanies the internal maxillary vein through the parotid 

 gland, gives filaments to the cutaneous and inferior auricular muscles, 

 and is connected with a branch of the n. cutaneus colli of the second 

 cervical nerve. 



(6) Several small branches (rami parotidei) end in the substance of 

 the parotid gland, where they help branches from the mandibular and 

 superficial temporal nerves in the formation of the 'parotid i^lexus 

 (plexus parotideus). 



N. TEMPORALIS SUPERFiciALis.— The small transverse facial ramus 

 of the superficial temporal nerve was observed earlier as it lay on the 

 surface of the masseter muscle in company with the transverse facial 

 vessels; and a larger ventral branch has been noted as joining the 

 ventral buccal nerve. 



A deeper part of the superficial temporal nerve (a branch of the 

 mandibular) is now exposed immediately behind the mandibular joint 

 and in contact with the joint-capsule. Small branches to the parotid 

 gland (rami parotidei), diverticulum of the Eustachian tube, external 

 ear, and the inferior auricular muscle (rami auriculares) should be 

 sought. 



The diverticulum of the auditory tube. — Before any further 

 disturbance of structures takes place, it is well to make as thorough 

 an examination of the diverticulum of the auditory tube of Eustachius 

 as present circumstances permit. A small opening should be made into 

 the diverticulum close to the border of the mandible and just above the 

 insertion of the sterno-cephalic muscle. No attempt should be made to 

 expose the interior, but the cavity should be explored as completely as 

 possible with the finger. In this way it may be determined that the 

 diverticulum is a capacious sac extending from the base of the skull to 

 the wall of the pharynx, and continued backwards under the wing of 

 the atlas. The great cornu of the hyoid bone, sloping downwards and 

 forwards, forms a prominent ridge in the lateral wall of the diverticulum 

 and thus imperfectly divides the cavity into a small lateral and a large 

 medial part. 



The submaxillary gland (Glandula submaxillaris). — The posterior 

 end of the submaxillary gland is visible in the interval between the 

 wing of the atlas and the jugulo-mandibular muscle. Lying over this 

 part of the gland, and separating it from the parotid, is a sheet of 

 fibrous tissue that unites the tendons of the sterno-cephalic and brachio- 

 cephalic muscles. 



Further examination of the gland must be postponed. 



