110 SEVENTH REPORT—1837. 
cal irritation of the nerve immediately after an animal has been killed, 
is not followed by any muscular movements, provided that care be 
taken to insulate it from the pharyngeal branch of the par vagum ; and 
here, again, an important difference between the movements excited by 
irritation of the glosso-pharyngeal and those of the motor nerve is ob- 
served; for, while movements produced by the irritation of a motor 
nerve, such as the pharyngeal branch of the par vagum, continue for 
some time after the functions of the central organs of the nervous sy- 
stem have ceased, those from irritation of the glosso-pharyngeal are 
arrested as soon as all decided marks of sensation disappear. That the 
sense of taste is sufficiently acute after the perfect section of the nerve 
on both sides, to enable the animal readily to recognize bitter sub- 
stances. That it may probable participate with other nerves in the 
performance of the function of the sense of taste, but it certainly is not 
the special nerve of that sense. That the sense of thirst does not de- 
pend entirely upon this nerve. 
Pneumogastrie or Par Vagum Nerve-—From the results of thirty 
experiments upon the par vagum, he is convinced that severe indica- 
tions of suffering are induced by pinching, cutting, or even stretching 
this nerve, in almost all those animals operated on. In several experi- 
ments, in which the trunk of the par vagum was compressed by the 
forceps for a few moments, it was observed that in some of these cases 
powerful respiratory movements were thus produced, and were followed 
by struggles, yet no tendency to cough, and no act of deglutition which 
could be fairly attributed to this cause. 
Pharyngeal Branches of Par Vagum.—From seventeen experiments 
performed on dogs, either when alive or immediately after being de- 
prived of sensation, he concludes that these are the motor nerves of 
the constructors of the pharynx, the stylo-pharyngeus, and palatine 
muscles ; and that the sensitive filaments of these nerves must be com- 
paratively few, if, under ordinary circumstances, they exist at all. 
Section of the pharyngeal branch of the par vagum on both sides, was 
followed by very considerable difficulty of deglutition, in which the 
food appears to be forced through the passage bag of the pharynx by 
the powerful movements of the tongue, and of the muscles which moye 
the hyoid bone and larynx. 
Laryngeal Branch of the Par Vagum.—On irritating the superior 
laryngeal nerve by galyanism, or by pinching it with the forceps, when 
the glottis was exposed to view, no movement of the muscles which di- 
late or contract the aperture of the glottis is observed. Upon looking 
at the interior part of the larynx, upon which the external laryngeal 
branch of this nerve is chiefly distributed, vigorous contractions of the 
cricothyroid muscle, by which the cricoid cartilage is approximated to 
the thyroid, were always seen. On irritating the inferior laryngeal, 
obvious movements of the muscles which dilate and enlarge the aper- 
ture of the glottis followed. In some cases these moyements were very 
vigorous, and it was observed that these did not produce an enlarge- 
ment of the glottis, but, on the other hand, the arytenoid cartilages 
were approximated, so as in some cases to shut completely the aperture 
