will.\rd: cranial nerves of anolis carolinensis. 



83 



back far enough to reach the trunk ganghon. This was clone in an- 

 other series. The best demonstration however, of the course of the 

 vagus to show the trunk ganglion and the postganglionic branches 

 was furnished by a dissection of this region mounted in balsam. As 

 these structures lie underneath all muscles, it was possible to remove 

 the floor of the pharynx in this region and pin it out on cork and then 

 fix it in Vom Rath's fluid. The preparation, which consisted of the 

 mucous membrane, the blood vessels and the nerve trunk with all the 

 branches to the mucous membrane, was cleared and mounted on a 

 glass slide giving a diagrammatic picture of the distribution of the 

 nerves. A drawing (Fig. L) of a portion of such a preparation^- is given 



Fig. L. — Camera drawing of a portion of a dissection to show trunis: ganglion 

 of the vagus and the relation of ramus recurrens to the arterial arches. 

 This is part of a preparation made in the same manner as that showing dis- 

 tribution of motor VII (figure J). For vcr. X. read rcr. X. 



to supplement the plotting. It will be seen that no branches are 

 given off proximal to the ganglion, which lies just clear of the thymus 

 gland at its posterior end. The ganglion itself is a pear-shaped struc- 

 ture through the center of which there is a distinct fiber path. At its 

 distal end two very fine rami are given off, one {phx. X) mesally, to 

 the pharynx wall, the other {sy. X.) to the main sympathetic trunk. 

 The vagus nerve crosses the arterial arches on their ventral side and 

 reaches a position alongside the trachea just cephalad of the bronchial 

 division. As it nears the median line the ramus recurrens laryngis 

 {rcr. X.) is given off. It crosses the arterial arches on their dorsal 

 side thus forming the loop. The posterior ramus visceralis proper was 

 not followed farther than is shown in this preparation. It branches 



