220 PRACTICAL ANATOMY. 



conception reaches the ninth month of utero-gestation, its blood is distributed 

 for purification in an organ called the placenta. This placenta, while structur- 

 ally very different from the lungs, accomplishes for the blood of the foetus just 



Right innominate vein 



Vena cava superior 

 Right pulmonary artei~y 



Vena cava inferior 



Left branch of portal vein 



DUCTUS VENOSUS 



Umbilical vein 



Portal vein 



Right bnnifh <>f 

 portal vein 



Umbilical vein 



Umbilical arteries _ 1 



Hypogaitric artery 



Left innominti/p 

 vein 



Arch of aorta 



DUCTUS ARTERIOSUS 



Left pulmonary 

 artery 



Descending aorta 



Superior 

 mesenteric artery 



Inferior 

 mesenteric artery 



Left common iliac 

 artery 



I nt f rnnl i/iui- uri, 



Kill-null /linear/ fry 



;. 155. THK HKART, WITH TIIK ARCH <>i THK AORTA, TIIK I'ILMONAKY AKTK.KY, 1111 I- 



Al; I I KloSUS, AND THE VESSELS CONCERNED IN TIIK Fd'.TAI. CIRCULATION. 

 (From a preparation of a foetus in the Museum of St. Bartholomew's Hospital.) 





the same results as are accomplished by the lungs /vW part cm. The purification 

 of the blood in cither case is in accordance with the law of physics regulating 

 the diffusion of gases. Blood, on entering lung or placenta, is laden with O )._, ; 



