SiGERSON — On the Study of Nerve- Action. 261 



which were not perceived on this side, were drawn across the mesial 

 line, there was an immediate contortion of the face. 



It follows, from the foregoing facts, that the nerve-supply pro- 

 ceeding from the otic ganglion is sensory as well as motor ; sentient 

 filaments of the fifth, and possibly loan-fibres of the glosso-pharyngens 

 accompany the motor nerves to the palatine region. 



II. 



Function of the Lingual Nerve — The function of the lingual branch 

 of the trigeminus has been a subject of dispute, especially since Pan- 

 nizza of Pavia denied, in 1834, its connexion with the sense of taste, 

 which he considered to be under the exclusive sovereignty of the 

 glosso-pharyngeus. According to his view, the lingual was solely 

 concerned with the tactual sensibility of the tongue. Magendie, five 

 years later, propounded a doctrine which was the exact contradictory 

 of this opinion; for he maintained that the lingual is, and is ex- 

 clusively, a nerve of taste. Against this it is asserted that he must, in 

 operating, have mistaken a pharyngeal branch of the pneumogastric 

 for the glosso-pharyngeus, and that he, consequently, drew his con- 

 clusions from faulty premisses. More trustworthy testimony against 

 the contention of Pannizza is to be found in the experiments of 

 J. Miiller, and especially in the later experiments of my friend Pro- 

 fessor Schiff, of Geneva. The result of their researches goes to prove 

 that taste is not quite abolished when the glosso-pharyngeus is 

 divided, though it is greatly diminished. It is true that the animals 

 operated on (dogs and cats) did not refuse to lap milk with which 

 colocynth had been mingled ; but, on the other hand, when pure milk 

 was placed alongside of milk so prepared with a bitter, they displayed 

 a distinct preference for the former. This would appear to demon- 

 strate that the trigeminal nerve-supply is capable of conveying 

 gustatory sensations of some kind. Hirschfeld and Valentin, how- 

 ever, have supported the opinions of Pannizza on anatomical grounds. 

 Yarious experiments have shown that, of the anterior part of the 

 tongue, the dorsum is scarcely, if at all, susceptible of receiving taste- 

 impressions, whilst the edges and point are sensitive to them. 

 Hirschfeld and Valentin maintain that the difi'erence is due to the 

 anatomical fact discovered by them, namely, that an external branch 

 of the glosso-pharyngeus proceeds along each margin of the tongue to 

 the tip. Hence, they hold that Pannizza's view still remains the 

 correct one, asserting that the glosso-pharyngeus is the sole nerve of 

 taste. Their adversaries, however, declare, on the other hand, that 

 as the lingual nerve sends a recurrent branch to the base of the 

 tongue, the sensibility to sapid impressions existing there, which has 

 been referred altogether to the distribution of the glosso-pharyngeus, 

 must be claimed for the lingual nerve. 



I may here point out that, if either of these doctrines be accepted, 

 and it be granted that the sense of taste is the exclusive appanage 



