170 THE NEEVOUS SYSTEM. 



The third branch of the palatine nerve (c) curves directly out- 

 wards, just behind the palatine bone, to the inner surface of the 

 maxillary bone ; it then courses backwards, pierces the fibrous 

 plate (dti) between the eyeball and the pterygoid bone, and ulti- 

 mately unites with superior maxillary division of the trigeminal 

 nerve (Vc}. Just before piercing the fibrous plate it gives off a 

 tolerably large nerve (d) to the mucous membrane, and in its whole 

 course it gives off twigs to the mucous membrane and surrounding 

 structures ; many of these twigs inosculate with other terminal 

 twigs of the trigeminal. 



[This nerve has been minutely described by Stirling and Mac- 

 donald ; these observers find that the branches form a very fine and 

 close plexus in the mucous membrane, etc. ; fibres were traced to 

 blood-vessels, glands, etc., and ganglion cells were found scattered 

 along the nerves. The fibres are both medullated and non-medul- 

 lated, and many of the cells are described as ' spiral cells ' (see page 

 201), such as those described by Arnold in the sympathetic system 

 of the frog.] 



b. The Ramus maxillo-mandibularis (Ramus maxillaris, Ecker and 

 Hoffmann ; Supra-maxillary, Humphry; Upper Maxillary Branch, 

 Wyman), (Figs, in, 112, and 113 Vc\ This nerve is the largest 

 division of the trigeminal ; it runs directly outwards behind the 

 eyeball, in front of the auditory capsule, and between the temporal 

 and pterygoid muscles. After a very short course it divides into the 

 maxillary and mandibular nerves. The nerve gives off before its 

 division a few fine filaments (i } i) to the hinder half of the upper 

 eyelid and to the surrounding skin, also a branch (h) [not correctly 

 drawn in Fig. in] which divides to supply twigs to the temporal 

 and pterygoid muscles. 



(i) The Ramus maxillaris (Ramus supramaxillaris, Ecker; Ramus 

 maxillaris superior, Hoffmann ; Upper Maxillary Branch, "Wyman ; 

 Supramaxillary, Humphry and de Watteville), (Figs, m, 112, 

 113, and 114 Vc) runs outwards and then forwards, between the 

 eyeball and the outer wall of the orbit, to the margin of the upper 

 jaw (K) ; a large portion terminates in a number of small branches 

 for the supply of the skin of the lower eyelid, the upper lip, and of 

 the parts between the tympanic membrane and the external nares. 

 Some of these twigs inosculate with twigs of the palatine and 

 ophthalmic nerves. The second portion of the nerve unites with 

 the palatine nerve, as already described. 



