VAGUS NERVE OF THE TURTLE 305 
small communicating branch to the glossopharyngeal nerve given 
off at the level of this ganglion. Neither of these branches were 
identified in the series from which figure 1 was reconstructed. 
The relations of the sympathetic trunk and the descendens 
hypoglossi to the vagus are well illustrated in the figures and 
need not be described in detail. Below the level of the laryn- 
gopharyngeal branch four nerves—the sympathetic trunk, the 
descendens hypoglossi, and the esophageal and thoracoabdominal 
branches of the vagus—are included in a single connective 
tissue sheath. In the lower part of the neck the esophageal 
branch and the descendens hypoglossi have left the common 
rtvand ts. 
rtv 5 
Fig. 1 Diagrammatic reconstruction from serial sections of the upper part 
of the right vagus nerve in the snapping turtle. The nerve is viewed from in 
front with the more proximal part in the left hand figure. a, ramus descen- 
dens hypoglossi; b, N. hypoglossus; c, ramus thoracoabdominalis vagi; d, ramus 
cervicalis vagi; d’, N. esophageus; d’’, N. laryngopharyngeus; e, truncus sym- 
patheticus; g.c.v., ganglion cervicale vagi. 
Fig. 2 The vagus of the snapping turtle in the upper part of the thoraco- 
abdominal cavity. r.t.v., ramus thoracoabdominalis vagi; ¢.s., truncus sympa- 
theticus; g.c.m., ganglion cervicale medium of the sympathetic trunk; g.t.v., 
ganglion thoracoabdominale vagi. 
