mi: niAMAL nn r.M-r.riiAi.n- .\ /:/, r/ - 711 



which receive these fibres, are in communication with several cranial nerves, 

 particularly the pnenmogastrio, glosso-pharyngcal, facial, and auditory. 



Ni miliinar or Gasserian ganglion. This ganglion, \vliicli receives the 

 tive root of the trigeminus, is crescent shaped, its concavity being 

 turm-d backwards and inwards. It may be said to bo imbedded in the 

 libro-cartilaginous substance which in part closes the occipito-splu no- 

 temporal hiatus, and divides it into several particular foramina. Its 

 superior face is covered by the dura mater, and sends a number of filaments 

 I - that membrane. 



The Gasserian ganglion is not continued by a single trunk, but imme- 

 diately gives rise to two thick branches, one of which leaves the cranium 

 by the foramen ovole an opening formed by the above-named hiatus ; 

 while the other is lodged in the external fissure in the iutcrcrauial face of 

 tin sphenoid bone, and passing along it as far as the entrance to the supra- 

 sphenoidal foramina, bifurcates. 



Hence it results that the trigeminus is divided, even at its origin, into 

 three branches: two superior the opk&abmc branch of Willis, and the 

 superior maxillary nerce, commencing by the same trunk ; and an inferior, 

 which constitutes the inferior maxillary nerve. 



Motor or small root (Figs. 337, 338). This is a flattened band which 

 emerges from the pons Varolii, at the inner side of the principal root. Its 

 fibres may be easily followed to the interior of the pons Varolii, and in their 

 direction they comport themselves like those of the large root, by becoming 

 confounded with the substance of the antero-lateral fasciculus of the 

 medulla oblongata. Leaving the pons, this root passes forwards on the 

 inferior face of the Gasserian ganglion, which it crosses in a diagonal 

 manner outwards, and beyond which it intimately unites with the fibres 

 of the inferior maxillary nerve. The superior maxillary nerve and the 

 ophthalmic branch do not receive any fibres from it. In the fifth pair, then, 

 it is only the inferior maxillary nerves which are at the same time sensitive 

 and motor, and are real mixed nerves. 



A. OPHTHALMIC BUANCH (Fig. 335, 1). This is the smallest of tin 

 three divisions furnished by the Gasseriau ganglion, and proceeds by a 

 trunk common to it and the maxillary nerve, which will bo described lu n- 

 ai'ter. This branch enters the smallest of the large suprasphenoidal 

 foramina, along with the common and external oculomotor nerves, and 

 in the interior of this bony canal divides into three ram uscules, which reach 

 the bottom of the ocular sheath by the orbital hiatus. 



These ramuscules ore : 



1. Tbo frontal or nm>ra-rbii>d 



2. The Ia<-]i>-i//ii<il / 



.".. The nasal or palpebro-nasal nerve. 



1. FRONTAL NEKVE ( Fig. 335, 4). This is a Hut, voluminous brunch 

 jihieeil on tlie inner wall of the ocular sheath, and proceeding nearly parallel 

 with the great oblique mu>clo of the eye to the supra-orbital foramen, into 

 which it passes along with the artery of the same name. Undivided l.< Ion- 



trance into this orifice, immediately al't< r it - i xit from it, it separates 

 into several ramusculcs, whi< -h im et the anterior auricular nerve, and are 

 n.l. .1 in the skin of the forehead and upper eyelid. 



2. LACIIUYMAL NKU\K (Fig. 335, 3). This is composed of .. 

 filaments, which ascend betwi . n tin ocular sheath and the elevator n 



of the eyelid and superior ivrtus. to enter the lachrymal trland. One of 



