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small, t'.uins part of the facial nerve, on which it only presents a kind of 

 intumescence. We have never seen tin- sharp and precise limitation of its 

 base that is figured in the majority of iconographies of human anatomy. 



the other hand, when, on portions steeped for several weeks in water 

 acidulated by nitric acid, we Lave studied the constitution of the great 

 is nerve, even at its origin, we have found it formed of two fasciculi 

 !y separated -one internal, the other external : the latter alone is 

 continuous with the geniculated ganglion ; the other traverses the facial 

 nerve from before to behind, then it is suddenly inflected inwards to ascend to 

 igin of the nerve, and mix with its fibres ; but this fasciculus very often 

 maintains its independence to the medulla oblougata, into which its fibres 

 penetrate separately; they then appear as a small particular trunk beside 

 that of the principal nerve, and comprised between it and the auditory. 

 The great petrous nerve does not, therefore, proceed exclusively from the 

 ganglion geniculare, as considerable portions of its fibres, entirely destitute 

 mglionic corpuscles, emerge directly from the facial nerve. With 

 regard to the external fasciculus, the separation of its fibres by the action of 

 the acid shows very plainly that the grey substance of the ganglion is found 

 almost exclusively on their track; and if wo trace these fibres, like those of 

 the preceding fasciculus, into the substance of the facial nerve, we will find 

 that, instead of proceeding towards its origin, they appear to be directed 

 t" its termination: a remarkable circumstance, which we believe may be 

 explained by admitting that they come from the anastomosing branch of the 

 pneiimogastric nerve, of which we will speak hereafter. 



From this arrangement, it results that the great petrous nerve arises 



from the facial by t.vo real, though intimately connected, roots : the internal 



. ideutly motor; the internal possesses the ganglionic corpuscles of a 



ive root ; and the trunk they both form may be regarded as a mixed 



nerve. 



As mil be observed, our view of the ganglion geniculare differs from 

 the general opinion with regard to it, inasmuch as we make it belong 

 exclusively to the great petrous nerve, and not to the whole of the facial 

 fasciculi. On the other hand, the portio intermedia of Wrisberg is not, in our 

 opinion, the sensitive root of the facial, whoso fibres we only look upon as 

 motor ; it is not even that of the great superficial petrous nerve, of which it 

 might at the most be considered as only an accessory filament. Jn the Horse, 

 this ramusculo is extremely attenuated, imd can scarcely, if at all, be dis- 

 tingui>hed at its origin from the filaments of the lateral root of the auditory 

 nerve ; it is seen to enter the aqueduct of Fallopius, and divide on the bend 

 angliform enlargement) of the facial nerve into several gradually 

 diminishing filaments, which are confounded with the proper fibres of this 



. or the ganglion geniciilare. 



What a difference there is between this arrangement and that of the 



;l>le sensitive roots opposite the ganglia placed on their track ! Why 



;te to admit that this nerve of Wrisberg is on'y an anastomosing twig 



Mg from the auditory nerve to the facial ? Is it because of the radical 



ditVercnee in the properties of the two nerves? Nature, in bringing them so 



r, does not appear to have taken into account this ditl'en n<v ; 



and thd reason for this anastomosis might bo explained by the connections 



tho seventh pair maintains with the active portions of the auditory apparatus. 



it not tho facial nerve that animates tho stapcdius muscle, and, in an 



indirect manner, that of the malleus? Are all the muscles of the external ear 



not under its influence? In tho present state of science it would be difficult 



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