844 THE NERVES. 



difference in the form of the head. Consequently, in this comparative analysis we shall not 

 discover any fundamental differential characters. 



Ruminants. — There is no difference to note in i\iti four fir4 pairs. 



Trigtminal nerve. — Divided into three branches as in Solipetis. It has been stated that in 

 Rumiijants the ophtliahnic branches are distributed to the mnjorily of the muscles of the eye ; 

 in the Sheep, we have only seen the palpehro- nasal nerve offering this relationship to the 

 motor orgaTis of that part. The anterior palatine nerve is relatively voluminous. 



In the Ox and Sheep, the buccal nerve furnishes the excito-secretory nerve of the parotid 

 gland; it is inflected on the anterior border of tlie m;isseter, and follows Steuo's duct, in both 

 species, to reach the gland. It is often formed by two parallel filaments (Moussue). A filament 

 of the inferior branch of the buccal nerve which goes to the molar gland, is also excito-secretory 

 (Moussu). 



Facial nerve. — Towards the middle of its subparotideal course, this gives off a large 

 anterior auricuhr nerve ; when it arrives at the middle of the posterior border of the luasseter 

 muscle, it divides into two branches. The inferior branch piisses obliquely downwards and 

 forwards, towards the mental foramen, where it terminates as in the Horse; it furnishes an 

 anastomotic branch to the superior. The latter crosses the middle portion of tlie masseter, and 

 becomes mixed with the suborbital ramuscules of the fifth pair; about the middle of its 

 course it receives a filament from the superficial temporal nerve. We need not allude to the 

 auditory and glosso-pharyngeal nerves, except to say that the latter communicates with the 

 pneumogastric soon after its exit from the foramen lacerum. 



Pneumognstric nerve. — This offers numerous differences in its roots and distribution. 

 In the Ox and Sheep, the sensitive roots arise from an irregularly ellijitical surface com- 

 prising the whole of the respiratory tract. They are from fifteen to twenty in number, and 

 often join each other; they may divide into three principal fasciculi ari.siug at slight distances. 

 The motor roots are a little larger than in the Horse ; before joining the sensitive roots they 

 are confounded in a small ganglion that pertains to them. 



The jugular ganglion is voluminous, but apart from this it presents the same features as in 

 the Horse, receiving all the proper mots of the pneumogastric and internal root of the spinal 

 accessory, and even those which are united in their own ganglion. The portion of the 

 ganglion that is more especially formed by tlie roots of the spinal accessory is ratlier an intri- 

 cation of nerve-fibres tlian a real ganglion ; it is impossible by the most minute dissection to 

 separate it from the rest of the ganglion. 



The jugular ganglion also receives a division of the glosso-pharyngeal, and it gives one to 

 this nerve and the external braneli of the spinal accessory. 



The pneumogastric nerve, in the guttural portion, is much larger than in the Horse. This 

 peculiarity is noticeable throughout its whole extent, and is indicated at its roots. 



The ganglionic plexus is absent in the Ox. The course and relations of the nerve in this 

 portion, are analogous to those observed in Solipeds. 



The pharyngeal nerve is voluminous, and tlie branch it sends to the oesoidiagus is the 

 largest of its divisions : this branch passes backwards to the surface of the constrictors of the 

 pharynx, joins the external laryngeal, gives a large branch to the tliyro-pharyugeus, and is 

 insinuated on tiie sides of the oesophagus, between it and the thyroid gland ; there it divides 

 into two portions, one of which descends on the sides of the cesophagus, where it forms a very 

 rich plexus with the branches from the inferior laryngeal, while the other is lost immediately 

 in the recurrent nerve at tlie thyroid gland. 



The external laryngeal arises at a short distance above the superior laryngeal, where it 

 receives a large brunch from the glosso-pharyngeal and anothe; from tiie sympathetic, and 

 immediately passes alongside the oesophageal branch of the pharyngeal nerve. Willi a little 

 attention, we may dissect a fasciculus coming from the extrrual laryngeal and passing to the 

 crico-thyroid muscle, and the thyroid gland and its vessel;?, after receiving a branch from 

 the superior laryngeal. In the Sheep, the external laryngeal sometimes gives a branch to 

 the cesophagus, and which anastomoses with the inferior laryngeal, or descends on the side 

 of the tube, conjointly with the oesophageal branch of the pharyngeal. 



The superior laryngeal rises below the preceding; it is very voluminous, and communicates 

 with the sympathetic, either directly or through the medium of the guttural plexus, and with 

 the pharyngeal nerves and external lnryngeal. Beneath the thyroid cartilage, a large division 

 anastomosis with the inferior laryngeal, and is finally lost in that nerve below the larynx It 

 ie easily seen that this branch gives, in the cervical region, a great number of filaments to the 

 cesophagus and trachea. 



With the exception of some insignificant peculiarities, the pneumogastric comports itself In 

 the cervical and thoracic regions as in the Horse. 



