Johnston, Nerves of Petromyzonts. 597 



pathetic trunks supply visceral surfaces merely. However, the 

 facts that these fibers do supply blood vessels and that the fibers 

 which are known to be visceral sensory enter the gill sacs by 

 another route lead me to conclude that when fibers from the sym- 

 pathetic trunks enter the gills they are still destined to the supply 



Fig. 23. A branch of the ventral sympathetic trunk of the left side ramifying in the ventral wall 

 of the third gill sac. Compare fig. ii. Magnification, 75 diameters. Many fine fibers are not drawn. 



of blood vessels found there. An illustration of the ramification 

 of these fibers on the wall of the sinus at the base of the gills is 

 given in fig. 23, taken from one of the sections drawn in fig. 11 

 where the position of this bundle will be seen. It lies beneath 

 the third gill sac on the left side and is a branch from th^ ventral 

 trunk. 



