Diagrammatic represen- 

 tation of'the cardial inhibi- 

 tory and augmentor fibers 

 in the dog. The upper por- 

 tion of the figure represents 

 the inhibitory, the lower the 

 augmentor fibers (Foster): 

 r.Vg., roots of the vagus; 

 r.Sp. Ac., roots of spinal 

 accessory, both drawn very 

 diagrammatically; G.J., 

 ganglion jugulare; G Tr. 

 VG., ganglion trunci vagi; 

 Sp.Ac., spinal acces-sory 

 trunk; exl.Sp.Ac., external 

 spinal accessory; I.Sp.Ac., 

 internal spinal accessory; 

 V.g., trunk of vagus nerve; 

 n.c., branches going to heart; 

 C.Sy., cervical sympathetic; 

 G.C., lower cervical gang- 

 lion; A.sb., subclavian 

 artery; An V., annulus of 

 Vieussens; G.St. t (Th. l ) t 

 ganglion stellatum, or first 

 thoracic ganglion; G.Th. 2 , 

 G.Tk.*,G.Th*. second, third, 

 and fourth thoracic ganglia ; 

 D.I1, D.III, D.IV, D.V, 

 second, third, fourth, and 

 fifth thoracic spinal nerves; 

 r.c., ramus communicans; 

 n.c., nerves (cardiac) pass- 

 ing to heart (superior vena 

 cava) from cervical gang- 

 lion and from the annulus 

 of Vieussens, 



The inhibitory fibers, 

 shown by black line, run in 

 the upper (medullary roots) 

 of the spinal accessory, by 

 the internal branch of the 

 spinal accessory, past the 

 ganglion trunci vagi, along 

 the trunk of the vagus, and 

 so by branches to the super- 

 ior vena cava and the heart. 



The augmentor fibers, 

 also shown by black line, 

 pass from the spinal cord 

 by the anterior roots of the 

 second and third thoracic 

 nerves (possibly also from 

 fourth and fifth as indicated 

 by broken black line), pass 

 the second and first (stel- 

 late) thoracic ganglia by 

 the annulus of Vieussens to 

 -the lower cervical ganglion, 

 from whence, as also from 

 the annulus itself, they pass 

 along the cardiac nerves to 

 the superior vena cava. 



G.Tr.rg.- 



