extraordinary Human Foetus. 12 7 
the usual way, and communicated with each other by a ductus 
arteriosus. The blood conveyed by the pulmonary artery 
passed to the lungs situated on the left side of the chest. 
From t lie arch of the aorta, the two carotid arteries were sent 
off in one trunk, which soon divided. The vertebral and in- 
ferior thyroid arteries, with the left axillary artery, were 
detached from the aorta, after it had almost completed its 
arch, and had received the ductus arteriosus'. This aorta soon 
afterwards united with the aorta of the right heart, and des- 
cended as one trunk, embedded in the hollow between the 
two spines, and resting upon the short ribs, which were con- 
nected with them. 
With regard to the veins which entered this heart, those 
from the lungs terminated in the left auricle, in the usual way. 
The vena cava superior terminated in the right auricle, and 
had this peculiarity, that it not only received the blood from 
the jugular veins of the left head, and from the left subclavian 
vein, but from the right subclavian vein also, and from the 
jugular veins of the right head. There was also a large ves- 
sel, which will be noticed afterwards, forming a communica- 
tion between the vena cava superior of this heart (the left), 
and the vena cava inferior of the right heart. The principal 
peculiarity, however, cf this heart Consisted in a partial defect 
of the vena cava inferior. A large vein, which entered the 
lower part of the rigut auricle, was formed by the venae cavae 
hepaticae, and two ductus venosi, which were smaller than 
natural. 
The heart situated towards the right side of the chest 
differed in many respects from that on the left, both in the 
relative situation of the vessels which arose from it, and in. 
