Junction of Vagus with Superior Cervical Ganglion. 331 



"Note on the Experimental Junction of the Vagus Nerve with 

 ihe Cells of the Superior Cervical Ganglion." By J. N. 

 L ANGLES, D.Sc, F.R.S., Fellow of Trinity College, Cam- 

 bridge. Received January 26, — Read February 3, 1898. 



Two experiments were made on cats. The central end of the 

 vagus, cut a little below the larynx, was turned forward and joined 

 to the peripheral end of the cervical sympathetic. The object of the 

 experiments was to see whether the vagus nerve fibres are capable of 

 forming connexions with any of the structures with which the 

 spinal nerve fibres of the cervical sympathetic are normally con- 

 nected. The results seem to me to be conclusive as regards this 

 point. 



The time allowed for regeneration was in one case 73 days, and in 

 the other 123 days. At the eud of these periods anaesthetics were 

 again given, and the nerves stimulated. 



Stimulation of the sympathetic in the lower region of the neck, 

 i.e., of its central end, gave no effect of any kind. Hence the 

 central end of the sympathetic had formed no functional Connexions 

 with the peripheral end. 



Stimulation of the sympathetic a little below the superior cervical 

 ganglion caused reflex effects of the kind caused by vagus stimula- 

 tion. These reflexes were obvious in the case in which 123 days 

 had been allowed for regeneration, less clear in that in which seventy- 

 three days only had been allowed. They ceased on section of the 

 vagus close to the ganglion of the trunk. Thus afferent fibres of the 

 vagus had grown outwards amongst, or joined with, the fibres of the 

 peripheral end of the sympathetic. 



The stimulation also caused all the effects normally produced by 

 stimulation of the cervical sympathetic, so that, although the central 

 end of the sympathetic had not joined the peripheral end, the 

 peripheral end had acquired more or less completely its normal 

 function. 



Stimulation of the vagus a little below the ganglion of the trunk 

 — the nerve being cut centrally of the' point stimulated — caused 

 dilation of the pupil, retraction of the nictitating membrane, con- 

 traction of the arteries of the ear, erection of the hairs of the face 

 secretion of the sub-maxillary gland, and the other effects normally 

 caused by stimulating the cervical sympathetic. 



After injection of nicotine no effect was obtained by stimulating 

 the nerves centrally of the superior cervical ganglion; the usual 

 effects following when the ganglion itself was stimulated. 



Hence, efferent fibres of the vagus had either grown along the 



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