446 



The Vessels of the Lung of Necturiis ^laculatus 



The pulmonary artery (Fig. 1, F. A.) arises from the third (fourth) 

 efferent branchial artery after it has been joined by the second efferent 

 artery and lateral to the entrance of the anastomosing branch from the 

 first efferent artery. It rims obliquely towards the lung, giving off along 



Fig. 1. The blood-vessels of the lung of Necturus. A., aorta; E.B., efferent 

 branchial arteries; E. C. external carotid; I. C internal carotid; Ph., oesoph- 

 agus; P. A., P. A'., pulmonary artery; P.h., P. oe., P.s.. branches of the 

 pulmonary artery outside of the lungs; P.V., pulmonary vein; R. A., R.A'., 

 aortic roots. 



its course small branches to the muscles of the shoulder, to the group of 

 muscles lying ventral to the Ijuccal cavity and to the cesophagus (Fig 1, 

 P. s., P. h., P. (E.). The artery now passes across the dorsal surface 

 of the lung to gain its dorso-mesial side, along which it runs, gradually 

 diminishing in size, to its tip (Fig. 1, P. A/). Throughout the course 



