152 



DR. C. F. SONNTAG ON THE VAGUS AND 



The Cardiac Nerves (text-fig. 6,/*) arise on the left side from the 

 vagus distal to the oi'igin of the left recurrent nerve, but the 

 right ones arise from the vagus and its recurrent branch. They 

 run to the cardiac plexus whei-ein they become associated with 

 the sympathetic (c.B.s). 



The oesophageal nerves (text-figs. 6, oisr, 7, on, and 8, vb) arise in 

 the neck from the cords uniting the laryngeal nerves. In the 

 upper part of the thorax they are branches of the right vagus, 

 but they come from the two divisions of the left vagus distal to 

 the roots of the lungs. 



The tracheal nerves (text-figs. 6, t.n and 7, t.n) arise from the 

 laryngeal cords in the neck, but its terminal part and the main 

 bronchi receive their nerve-supply from the thick bridge between 

 the vagi (hr). 



Text-figure 7. 



The Lower Thoracic and Abdominal Parts of the "Vagus Nerves of Si/rax 

 capensis. L. V : parts of left vagus ; E.V : right vagus. Other letters 

 in text. 



The pulmonary plexuses (text-fig. 7,g): — The right one is 

 formed by two brauches from the i-ight vagus and communi- 

 cating twigs from the deep cardiac plexus. But the left one 

 consists of many branches from the bridge between the two vagi. 

 The latter sends a branch to the aortic 2:)lexus (a.p), which receives 

 many twigs from the left vagus. And no ganglia were found in 

 the pulmonary and aortic plexuses. 



The Gastric Nerves (text-fig. 7) : — The left vagus reaches the 

 stomach along the ventral border of the oesophagus and breaks 

 up into two branches. The first gives oflf twigs which run along 



