1 34 Mr. Gibson's Description of an 
the vena cava inferior of the right heart, and the vena cava 
superior of the left heart 
28. Vena cava superior, terminating in the right auricle of the 
left heart. 
29. A trunk formed by the left subclavian vein, and the jugu- 
lar veins of the left side of the left head. 
go. A trunk formed by the jugular veins of the right side of 
the left head. 
31. A trunk formed by the jugular veins of the left side of 
the right head. 
32. A trunk formed by the right subclavian vein, and the 
jugular veins of the right side of the right head. 
Explanation of Plate IV. 
Posterior View of the Hearts and Arteries. 
1. Left heart. 
2. Right heart. 
3. Ductus arteriosus of the left heart. 
4. Ductus arteriosus of the right heart. 
5. The arch of the aorta of the right heart, where it receives 
the ductus arteriosus. 
6 . A trunk, from which the vertebral and inferior thyroid ar- 
teries, with the left axillary artery, arose from the aorta. 
7. The left vertebral artery of the right head, arising from 
the arch of the aorta, just as it receives the ductus 
arteriosus. 
8. A trunk arising from the ductus arteriosus, which supplied 
the right vertebral, the right axillary, and the inferior thy- 
roid arteries. 
