CHAP, iv.] THE VASCULAR MECHANISM. 247 



This being the case, we may expect that we should get different 

 results according as we stimulated (1) the vagus in the cranium, 



FIG. 69. DIAGRAMMATIC REPRESENTATION OF THE COURSE 

 AUGMENTOR FlBRKS IN THE FROG. 



op CARDIAC 



Vr. roots of vagns (and ixth) nerve. G V. ganglion of same. Cr. line of cranial 

 wall. Vg. vagus trunk, ix. ninth, glosso-phnryngeal nerve. <S. V.C. superior vena 

 cava. Sy. sympathetic nerve in neck. G. C. junction of sympathetic ganglion with 

 vagus ganglion, sending i.e. intracranial fibres passing t<> OttMriaa fUgwMk The 

 rest of the fibres pass along the vagus trunk, f/' sympathetic ganglimi c<>nnertp<! 

 with the first spinal nerve. G" sympathetic ganglion of the second spinal nerve. 

 An. V. annulus of Vieussens. A. sb. subclavian artery. G v// sympathetic ganglion of 

 the third spinal nerve. ///. third spinal nerve, r.c, minus commnnicaiia. 



The course of the augmentor fibres is shewn by the thick black line. They mar 

 be traced from the spinal cord by the anterior root of the third spinal nerve. tlirin;li 

 the ramns communicans to the corresponding sympathetic ganglion (i ltt and thence 

 by the second ganglion G", the annulus of Virii-srns. and tin- tirst gangln>n (i> to 

 the cervical sympathetic Sy, and so by the vagus trunk to the superior vena cara 

 o. V .G. 



before it was joined by the sympathetic, (2) the sympathetic fibres 

 before they join the vagus, and (3) the vagus trunk, containing bnth 

 the real vagus and the sympathetic fibres. What \vr have pre- 

 viously described are the ordinary results of stimulating the mixed 



