VAGUS NERVE OF THE TURTLE 309 
The cervical ramus at this level contains a few ganglion cells 
and serial sections show that all the cells of the superior ganglion 
are contained in this division of the nerve. At a somewhat 
lower level, figure 5, the cervical ramus with its ganglion has 
become separated from the vago-hypoglossal trunk by a con- 
nective tissue septum. The thoracoabdominal ramus of the 
vagus (c) remains free from ganglion cells. All the fascicles, 
except the cervical ramus of the vagus, present at this level 
the same structure as at higher levels. Another nerve enters 
Fig. 5 Section of the vagus at the level indicated by 4, figure 1. a, ramus 
descendens hypoglossi; b, N. hypoglossus; c, ramus thoracoabdominalis vagi; 
d, ramus cervicalis vagi with the ganglion cervicale vagi; e, truncus sympatheticus. 
Osmic acid. XX 36. 
the series at this point (fig. 5,e). It is the sympathetic trunk 
and has the same structure as the thoracoabdominal ramus of 
the vagus, except that its myelinated fibers are all small. These 
two nerves have about the same proportion of myelinated and 
unmyelinated fibers. 
Figure 6 is taken some distance below the ganglion. At this 
level the thoracoabdominal ramus of the vagus (c) accompanied 
by the descendens hypoglossi (a) has separated somewhat from 
the other fascicles of the common trunk. The cervical ramus 
