NERVE OF TASTE. 153 



that in fishes (pieces muti) it is wanting. It is likewise maintained, 

 that the fifth is the first encephalic nerve, which appears in the lower 

 classes of animated nature; as the taste is the first of the special 

 senses noticed in them ; that, at first, the nerve consists only of the 

 lingual branch ; and farther, that its size, in animals, is generally in a 

 ratio with that of the organs of taste and mastication. 



Certain experiments by M. Magendie 1 would seem to settle the ques- 

 tion definitely. On dividing the lingual branch of the fifth pair on ani- 

 mals, he found that the tongue continued to move, but that they lost 

 the faculty of appreciating savours. The palate, gums, and internal 

 surface of the cheeks, however, preserved the faculty, because supplied 

 with other branches of the fifth. But when the trunk of the nerve 

 was cut within the cranium, the power of recognising savours was com- 

 pletely lost in every part of the mouth, even in the case of highly 

 acrid and caustic bodies. He found, too, that the loss of sense occur- 

 red in all those who had the fifth pair morbidly affected, a fact, which 

 has been confirmed by observations of others. 2 



Experiments on dogs by Professor Panizza, of Pavia, led him to infer, 

 that the hypoglossal is the nerve of motion for the tongue ; the lingual 

 branch of the fifth pair, the nerve of general sensibility; and the 

 glosso-pharyngeal, the neuve of gustation. 3 The views of Panizza have 

 been embraced by Messrs. Elliotson, 4 Wagner, 5 Valentin, Bruns, 

 Broughton, 6 and others, and have been recently confirmed by the ex- 

 periments and observations of Stannius ; 7 and Mr. Broughton has 

 summed up what he considers to be the final results of all the comparative 

 inquiries. The communicating nerve of the face (portio dura), and the 

 fifth pair, arising by distinct roots, send off branches as they emerge 

 from the bed of the parotid gland, some of which unite in parallel lines, 

 and others do not, each ramification retaining the original property of 

 its own root unmixed; the one destined to govern certain motions of 

 different parts of the face ; the other devoted to tactile sensibility, as 

 far as regards the superficial parts of the face.. Thus far, there is no 

 disagreement : the whole development has been arrived at by repeated 

 experiments by different persons. In the next place, it appears, that 

 the hypoglossal governs the motions of the tongue ; deglutition ; and 

 mastication, without interfering with common sensation and taste. The 

 instinctive and voluntary motions of the tongue are all destroyed by 

 dividing this nerve. The next position is, that the lingual branches of 

 the fifth pair are devoted to tactile sensibility, or the common sensation 



1 Precis., i. 144, and Journal de Physiologie, t. iv. 



a Mr. Bishop, in Lond. Med. Gazette ibr^Dec. 12, 1835; and Romberg, Miiller's Archiv., 

 1838, H. iii. 



3 Ricerche Sperimentali sopra i Nervi, translated in Edinb. Med. and Surg. Journal, for 

 Jan., 1836, p. 70; see also, Amer. Journal of the Med. Sciences, May, 1836, p. 188; and 

 Mayo, Outlines of Human Physiology, 4th edit., p. 314, London, 1837. 



* Human Physiology, p. 536, Lond. 1840. 



6 Traite de Nevrologie, trad, par Jourdan, p. 433, Paris, 1843, and Lehrbuch der Physio- 

 logie des Menschen, ii. 679. Braunschweig, 1844. 



Edinburgh Medical and Surgical Journal, April, 1836, p. 431. A case in which there 

 was complete insensibility of every part supplied by the fifth pair, and the sense of taste 

 was perfect, is given in Bullet, dell Scienz. Medich., Aprile, 1841, cited in Brit, and For. 

 Med. Rev., Oct., 1842, p. 545. See, also, Bidder, Art. Schmecken,in Wagner's Handwcirter- 

 buch der Physiologie, loc. cit. v Muller's Archiv., s. 132-138, Berlin, 1848. 



