extraordinary Human Foetus. 133 
9. The trunk, from which the vertebral, the inferior thyroid 
arteries, and the left axillary artery, arose. 
10. The aorta after it has completed its arch, and is proceed- 
ing to unite with the aorta, from the heart of the right 
head. 
1 1 . The left ventricle of the heart, corresponding to the right 
head. 
1 2. The right ventricle. 
13. The aorta, arising from the right ventricle. 
14. The right external carotid artery of the right head. 
15. The left external carotid artery. 
16. The left vertebral artery, arising from the arch of the 
aorta as a distinct vessel. 
17. The pulmonary artery, where it detaches the ductus 
arteriosus. 
18. Branches of the pulmonary artery. 
19. A vessel detached from the ductus arteriosus, from which 
the right axillary, the right vertebral, and the inferior 
thyroid arteries, are derived. 
20. The point of junction between the aorta of the right and 
left heart. 
81 . The descending aorta. 
22. The umbilical vein. 
23. Two ductus venosi detached to the left heart. 
24,. A trunk formed by the venae cavae hepaticae. 
25. Large anastomoses formed between the branches of the 
vena portarum. 
2 6. The vena cava inferior, terminating in the left auricle of 
the right heart. 
§7. A large vessel, which forms a communication between 
