160 NERVOUS SYSTEM. 



Direct experiments upon the roots of the facial have not 

 been followed by uniform results. Debrou, in the thesis 

 just referred to, mentions one experiment in which galvani- 

 zation of the facial within the cranial cavity produced de- 

 cided contraction of the muscles of the palate ; but in four 

 others, the results were negative. Nuhn, however, pro- 

 duced contractions of these muscles by galvanization of the 

 nerve in the cranium in a man immediately after decapita- 

 tion. 1 The experiments of Bernard upon this point are the 

 most conclusive ; but while they show, beyond a doubt, that 

 the facial animates the movements of the soft palate, they 

 do not indicate the course of the filaments from the nerve 

 to the muscles. In these experiments, made in connection 

 with M. Davaine, the whole of the velum palati was exposed 

 in a large-sized dog, by cutting through the hyoid bone. The 

 trunk of the glosso-pharyngeal nerve was then exposed in 

 the neck, near its point of emergence at the posterior fora- 

 men lacerum, and the animal was killed by section of the 

 spinal cord just below the origin of the cranial nerves. This 

 being done, the glosso-pharyngeal was galvanized, which pro- 

 duced violent contractions of the velum, the pillars of the 

 fauces, and a part of the pharynx, on one side. The nerve 

 was then divided, and the galvanization applied to its pe- 

 ripheral end without producing any movement in the velum. 

 The central end was then galvanized, when the contractions 

 were as vigorous as when the nerve was intact. This result 

 would lead to the supposition that contractions of the mus- 

 cles of the palate following galvanization of the glosso- 

 pharyngeal are reflex and not due to the direct action of 

 filaments of distribution from this nerve. In a second ex- 

 periment, the parts were exposed in the same way, and, in 

 addition, the facial was divided upon the right side at its en- 

 trance into the internal auditory canal. The glosso-pharyn- 



1 NUHN, Versuche an einem Eiilhaupteten nebst erlduternden Versuchen an 

 Thieren. Zeitschrift fur rationelle Medicin, Heidelberg, 1853, Neue Folge, Bd. 

 fii., S. 129, et seq. 



