i86 



THE ENTODEEMAL CANAL AND THE BODY CAVITIES 



Pleural cavil) 



Right lung hud 



Pleuro-pericard i III 

 membrane 



Wall of hcaii 



Liv 



Esophagus 



Mesoderm of left lung bud^ 

 I'cr icardial cavity 



Pleuro-peritoneat 

 membrane 

 Phrenic nerve 



Septum transversum 



Falciform h^mi' iil _ 



Fig. 195. — Transverse section through a 10 mm. human embryo showing the pleuro-jiericardial mem- 

 brane separating the pericardium from the pleural cavities. X 33. 



Esophagus, I 

 Righl lung 



Coronary appendage of 

 liver 



Vena cava inferior 



Pleural eavilv 



Pleura- perilorxa'- 

 }}U'}nbranc 



Phreiiie nerve in septum 

 Iransversum 



Fig. 196. — Transverse section through a 10 mm. human embryo showing the pleuro-peritoneal mem- 

 branes. X 16. 



Owing to the caudal migration of the septum transversum and the growth of 

 the lungs and liver, the pleuro-peritoneal membrane, at first lying in a nearly 



