530 Prof. J. C. Ewart. 



and (2) the cranial, rostral, subrostral, and nasal mucous canals.* 

 These canals are described by Garrnan, one of the latest writers on 

 the subject, as being supplied by the trigeminal. It may be men- 

 tioned that the minute branches for the cranial canal spring from the 

 trunk of the nerve as it passes through the orbit and reach the surface 

 by piercing the cartilage of the roof of the orbit at short and nearly 

 regular intervals. A remarkable bundle of fibres runs obliquely 

 across the upper border of the ophthalmicus superficialis at its origin, 

 and reaching its anterior surface turns abruptly downwards to lie first 

 in front of and afterwards under the buccal nerve. These fibres then 

 form a plexus from which numerous twigs proceed to the conjoined 

 roots of fche hyomandibular and palatine nerves ; they probably even- 

 tually reach and end in ampullaB and mucous canals. 



5. The Buccal Nerve. This nerve (5, fig. 1) springs by a large root 

 from the side of the medulla, behind and on a slightly higher level 

 than the root of the trigeminal. As the root passes outwards, it lies in 

 the groove formed by the roots of the trigeminal and the posterior 

 portion of the facial complex. After communicating freely with the 

 ophthalmicus superficialis, it escapes with it through the cranial 

 walls. Leaving the ophthalmicus superficialis, it comes into close 

 contact with the outer surface of the Gasserian ganglion, and then lies 

 between the maxillary and mandibular branches of the trigeminal. 

 As the buccal nerve leaves the Gasserian ganglion, it presents a 

 distinct swelling which is crowded with large bipolar cells. This 

 may be called the biiccal ganglion. The buccal nerve beyond the 

 ganglion comes into intimate relation with the maxillary nerve, and 

 as it runs forward under the contents of the orbit, it breaks up into 

 branches which eventually reach the ampullaa and mucous canals of 

 the snout not supplied by the ophthalmicus superficialis. The buccal 

 nerve also sends branches to the anterior portion of the occipital 

 mucous canal, and to the posterior part of the cranial mucous canal, 

 and it sends a branch backwards which disappears under the hyo- 

 mandibular cartilage. Further, by means of branches which run 

 outwards, behind or under the contents of the orbit, the buccal 

 nerve supplies the orbital and suborbital canals, apparently without 

 any assistance from the maxillary and mandibular branches of the 

 trigeminal. 



The Palatine and Hijomandibular Nerves. These nerves arise by a 

 large root which lies between the trigeminal and auditory nerves, and 

 partly under cover of the buccal nerve. This root is augmented by 

 fibres from the plexus which, as mentioned above, is formed in con- 

 nexion with the bundle of fibres that arches downwards from the 

 ophthalmicus superficialis. Having received these additional fibres, 



* The names used for the mucous canals are those of Agassiz as modified by 

 G-arman. 



