CONSTITUTION OK CRANIAL NKKYIX 



387 



lino of I !'< |H, I -ri-ir ruol.s. Tin- ;iM'-rcnt, fibres, l>oMi . nm.'il i<- :in<l hplaiirlim. :n oil '. , I - of Um 



of st,af,ion:i.r\ y.-.n -lia (see below ) and tf''"w t,henoe into i hr rcrrhro-Hpinal axin. The 

 vcral cranial IKTVCN an; Hliown in Ui- following lal.lr : 



TAKLK SIloWI.N'i; TIIK CoXSTITI'TloN OK TIIK CRANIAL NKRVKS FROM 

 Till'] TlllltD TO TIIM TWKU'TII. 



Gangrlia. The ganglia in connection with cranial nerves also fall into the two groups, 

 stationary and vagrant, which have been characterized in dealing with the upinal norve* 

 I). 



StiiiiiHHi,-,/ ijuntji'in, necessarily occur only on those nerves which contain afferent fibres. 

 They are th ,\\ on the large root of the fifth' nerve, the geniculate ganglion 



on the portio intermedia, the acoustic ganglion on the auditory nerve (see p. 256), the jugular 

 and petrowal ganglia of the glosso-pharyngeal nerve, and the upper ganglion (possibly also the 

 lower) of the pneumo-gastric nerve. The nerve-cells are unipolar, like thone of the spinal 

 ganglia, in all of thene except the acoustic ganglion, in which the cells retain their primitive 

 bipolar form. There are also found upon the roots of the third, fourth, motor part of the 

 fifth, and seventh nerves traces of ganglionic structure which are regarded by Gaskell as 

 indications of the former existence of stationary ganglia and afferent fibres belonging to those 

 nerves. In some animalu, and in rare cases in man, there is moreover a gangliated posterior 

 root to the hypoglosal nerve. 



The vagrant ganylia in connection with the cranial nerves include four ganglia usually 

 associated with the fifth nerve, namely, the ciliary, spheno*palatine, submaxillary, and otic, 

 all of which are of sympathetic type, containing multipolar nerve-cells, and according to 

 Gaskell also the lower ganglion of the vagus, the cells of which are, however, of the spinal 

 type. The ciliary, spheno-palatine and otic ganglia are known to be developed as offsets of 

 the Gawerian ganglion, and the same is probably the case with the submaxillary ganglion, 

 but they receive splanchnic efferent fibres, with which they form physiological connections, 

 from other sources the ciliary ganglion from the third nerve, the spheno-palatine ganglion 

 from the facial nerve (portio intermedia ?), the submaxillary ganglion from the portio 

 intermedia through the chorda tympani, and the otic ganglion from the glosso-pharyngeal. 

 The condition in the last three cases resembles that in the sympathetic, where a given ganglion 

 of the cord, presumably derived from the spinal ganglion of the wuw Moment, receives 

 efferent fibres from spinal nerves at different levels. 



