CRANIAL AUTONOMIC NERVE FIBRES. 66 1 



secretory and vaso-dilator fibres run together, the question can hardly 

 be considered as definitely settled. 



The fibres of the seventh nerve, which run by way of the lingual 

 branch of the fifth to the submaxillary and sublingual glands, end in 

 the submaxillary and sublingual ganglia, from which fibres (post- 

 ganglionic), both vaso-dilator and secretory, are given off. 1 We might 

 expect, then, to find similar ganglia on the course of the fibres which 

 the seventh and ninth send to the other branches of the fifth nerve. 

 The ganglia which occur in connection with the other branches occur 

 early on the course of the fifth instead of in or near the peripheral 

 organs. The spheno-palatine ganglion is in connection with the 

 superior maxillary nerve, and the otic ganglion in connection with the 

 inferior maxillary nerve. Since nicotin stops the effects of stimulating 

 the seventh and ninth nerves in the tympanic cavity, and does not stop 

 the effects of stimulating the peripheral branches of the fifth nerve, 

 there is some, though by no means conclusive, evidence that the spheno- 

 palatine and otic ganglia are on the course of the autonomic fibres 

 proceeding from the seventh and ninth nerves to the branches of the 

 fifth, other than the lingual. It is to be borne in mind that the fibres 

 of the seventh and ninth nerves which run to the fifth do not, so far as 

 we know, accompany the branches of the fifth which run to the skin, 

 but only those which run to the mucous membrane and glands. We 

 have, then, only ground for considering that the spheno-palatine and 

 otic ganglion send fibres to the branches of the fifth which run to the 

 mucous membrane and to the glands of the head. 



On this basis we should conclude that the spheno-palatine ganglion 

 sends vaso-dilator and secretory fibres to the mucous membrane of the 

 nose, soft palate, tonsils, uvula, roof of the mouth, upper lip and gums, 

 and upper part of the pharynx, and that the otic ganglion sends similar 

 fibres to the mucous membrane of the lower lip, cheek, and gums, the 

 parotid and orbital glands ; that the ganglia on the course of the lingual 

 send similar fibres to the anterior part of the tongue, the floor of the 

 mouth, the submaxillary and sublingual glands. 



In view of the anatomy of the parts, we should expect to find that 

 the spheno-palatine ganglion receives its pre-ganglionic fibres chiefly from 

 the seventh nerve, the otic ganglion chiefly from the ninth nerve, and this 

 is in general accordance with the result of physiological experiment. 



The scheme just given with regard to the arrangement of the cranial 

 autonomic fibres has simplicity on its side, and it is not inconsistent with 

 any well-established facts ; it is, however, in large part conjectural, and 

 we must await further experimental evidence for proof or disproof of it. 



There still remains to consider the cranial autonomic fibres to that 

 part of the tongue which receives its sensory fibres not by the fifth 

 but by the glosso-pharyngeal nerve. Experiments on this point were 

 made by Vulpian. He found that stimulation of the roots of the glosso- 

 pharyngeal nerve intracranially caused flushing of the posterior part of 

 the tongue ; and he considered that the vaso-dilator fibres ran direct in 

 the glosso-pharyngeal. We have no information as to any nerve cell 

 connection of these fibres. 



Some account of the observations which have been made upon the 

 cranial origin of the secretory and vaso-dilator nerves of the salivary glands 



1 See art. "The Salivary Glands," this Text- Book, Vol. I. p. 475. 



