WORK UPON VISCERAL AND ALLIED NERVES. 6i 



shown that the secretory fibres to the submaxillary gland 

 leave the cord mainly in the second and third thoracic 

 nerve roots ; once only has he obtained secretion from the 

 first, fourth or fifth thoracic. In the dog the origin is 

 slightly different. In this animal the first and second 

 thoracic always contain secretory fibres, the third, fourth 

 and fifth only containing some in one out of three cases. 



These fibres end in cells of the superior cervical gang- 

 lion.^ Thence passing through the grey rami of the gang- 

 lion the fibres reach the gland via the sympathetics on the 

 carotid and facial arteries. There are no further cells on 

 these fibres. The position of the cells on the course of these 

 sympathetic secretory fibres has also been located to the 

 superior cervical ganglion by the aid of the method of 

 degeneration. This has been effected by Langley- and 

 by Bradford '^ for the cat. 



The chorda tympani fibres to the gland have also been 

 shown to possess nerve cells on their course. In the doo- 

 these* are found on the course of the chorda tympani just 

 at its entrance into the hilum of the submaxillary gland or 

 shortly before this. In the cat many more are found in 

 the nerve before its entrance into the gland. The prse- 

 ganglionic fibres therefore are from the origin of the seventh 

 cranial nerve along the chorda to its termination at the 

 gland ; and the post-ganglionic from this point to their 

 distribution in the gland substance. Langley also shows 

 that the cells in the submaxillary ganglion and in the 

 triangle lying between the duct, the lingual nerve and the 

 chorda, are in connection with fibres to the sublingual gland 

 not to the submaxillary. 



By the injection of nicotine the sympathetic cells are 

 paralysed before the chorda cells, in the cat, and recover 

 later. In the dog they however recover quickly. 



The vaso-constricto7'- fibres to the submaxillary o-land 



^ Langley and Dickinson, Proc. Roy. Soc, vol. xlvi., p. 423, 18S9, and 

 hcLng\ey,/ot{rn. Physiol., no\. xi., p. 123, 1890. 

 '- Jonrn. of Physiol., vol. vi., p. 87, 1885. 

 ^ Ihid.^ vol. ix., p. 302, 1888. 

 ■* Loc. cit. 



