240 
MR. YOUATT’s VETERINARY LECTURES. 
fluence, to produce their more powerful and consentaneous action. 
I can account for their decidedly motor origin in the human being, 
and for the rounded head whence they spring being in the inferior 
surface of the chord in the quadruped ; for their function is that 
of motion. I can account for their sensitive ganglion, for it is 
necessary that there should be a sympathy and common feeling 
between all the parts concerned in the discharge of a certain func¬ 
tion, in order that their action may be suited to the situation and 
wants of the animal; and I can understand the anastomoses of 
these nerves with those of the spinal chord, that this sympathy 
may be more extensive and stronger, and the consent of numerous 
muscles in the discharge of the appointed function more complete. 
I have, therefore, no hesitation in denominating it an organic mo¬ 
tor nerve. 
I must here differ a little from him whose track I have grate- 
fully and cheerfully followed. I cannot call this a respiratory 
nerve, for the tongue is more concerned with deglutition , one of 
the processes of digestion, than it is with respiration. I term it 
an organic motor nerve; not in denial of the theory of Sir Charles 
Bell, but as comprising an extension of the inAuence of the nerve 
to other functions of organic life. 
The Portion of the JServe belonging to the Pharynx. —Vv hen 
you observe the mesh-work of nerves about the lower part of the 
face, and the larynx, and the throat generally, you can scarcely 
fail to remark how few, comparatively, from the spinal chord are 
given to the pharynx. There are two branches from the seventh 
which have considerable similarity to this glosso-phrayngeus, 
and which I shall in another lecture have to describe, viz., the 
chorda tympani, which, after performing its duty wuthin the ear, 
takes its course to the tongue, and another branch which may be 
traced to the styloid muscles, and the dilators of the pharynx gene¬ 
rally. The constrictors, how r ever, seem to be comparatively aban¬ 
doned, and the fibrils which they derive from the fifth, and the se¬ 
venth, and the upper cervical, render them voluntary muscles to a 
comparatively insufficient and imperfect degree. The truth of the 
matter is, that that portion of the mechanism of deglutition with 
which the constrictors of the pharynx are concerned is performed in¬ 
stinctively, without the command and in defiance of the resistance 
of the will. When a portion of food has entered the pharynx, 
and dilated it to a certain extent, the constrictors begin to act 
and press it onward, whether we will or not. It is an instinctive 
act, and performed by the foal and the lamb as perfectly as by the 
adult animal. The pharyngeal branch of the nerve under conside¬ 
ration, is that by which this portion of the act of deglutition is 
effected. It is to a certain extent, as every vital action should be, 
