G.Tr.Vg. Gan- 

 glion on the 

 trunk of the 

 vagus ; the black 

 line through it 

 is the internal 

 branch of the 

 spinal accessor^-. 



Vg. The vagus VtJ.. 

 nerve. 



nc, nc. The 

 cardiac branches 

 of the vagus con 

 veying inhibit- 

 ory fibres to the 

 heart. 



nc, nc. Car- 

 diac branches of 

 the sympathetic 

 conveying aug- 

 mentor fibres to 

 the heart. 



53 



r.Vo 



Inhibitory fibres from 

 on Ac. spinal accessory enter- 

 ing the vagus. 



G.Th.* and 

 G.Th. 5 Fourth 

 and fifth thora- 

 cic ganglia on 

 sympathetic 

 chain. 



C.Sy. The cervical 

 pathetic nerve. 



G.C. Inferior cervical 

 ganglion. 



Asb. Subclavian artery- 



An.V. Annulus of Vieus- 



G.St. Ganglion stellatum. 



D.1I , D.III. The inferior 

 " roots of the second and 

 third spinal nerves, pa^in^; 

 by means of r.c. the ramus 

 communicans to the gang- 

 lion stellatum. These are 

 the augmentor fibres, pass- 

 ing both by the annulus and 

 HI inferior cervical ganglion to 

 the heart by nc. nc. 



The dotted line in certain 

 thoracic nerves, D.I., D.IV., 

 and D.V., indicates that they 

 may contribute augmentor 

 fibres to the sympathetic. 



Fig. 21. — Diagrammatic Representation of the Cardiac Inhibitory and 



Augmentor Fibres in the Dog (Foster). 

 The upper portion of the figure shows the inhibitory, the lower the augmentor, 



fibres. 



