80 AYES. 



on the right side it extends over the arch of the aorta, and sends the slender recurrent 

 nerve round this vessel to the oesophagus ; it then gives branches to the lungs and 

 passes over the right branch of the pulmonary vein to the left side, to join the left 

 trunk, after it has given filaments to the pulmonary artery and vein. The left trunk 

 near the bifurcation of the trachea sends up its slender recurrent nerve, which gives 

 filaments to the trachea, but its principal part terminates on the oesophagus ; the par 

 vagum gives filaments to the lungs, and sends a large branch down on the oesophagus 

 to terminate on the enlarged part of this canal near the gizzard ; it then passes over 

 the pulmonary vein after it has given filaments to this and the pulmonary artery, it is 

 afterwards joined by the right trunk, so as to form one cord, which passes down on the 

 front of the oesophagus to terminate on the gizzard, after it has communicated with 

 filaments from the splanchnic nerves accompanying the cceliac artery. The lengthened 

 origin of the par vagum may resemble part of that usually belonging to the accessory 

 in mammalia. In the crane it descends, adhering to the spinal nerves ; it gives 

 branches to the trachea and lungs and the large vessels of the heart ; it sends off the 

 recurrent on each side, to give branches to the oesophagus, the lower larynx, and its 

 muscles ; it then sends a branch downwards on each side of the stomach ; the rest of 

 each trunk becomes joined in front of the oesophagus, passes on the stomach as far 

 as the cardiac extremity, and sends filaments to communicate with branches of the 

 splanchnic nerve, as well as the one passing on the coeliac artery. In the pelican, 

 after emerging from the cranium the par vagum becomes united with the glosso- 

 pharyngeal and ninth, and sends off a large branch to join the one proceeding 

 from its previous union with the glosso-pharyngeal ; it sends off another larger 

 branch to join this union ; it then receives a branch of the second cervical nerve, 

 and passes to its termination nearly, as in the crane. The ninth arises from the 

 oblong medulla ; after it has passed through its foramen it communicates with the 

 sympathetic. In the goose it gives a branch to the hyo-laryngeal muscle placed at 

 the side of the trachea, and sends a large branch forwards to give a branch to the 

 hyo-glossal and lingual muscles. In the crane and pelican it becomes connected with 

 the glosso-pharyngeal, 



