PRENATAL AND NEONATAL LUNG 



209 



A careful examination shows that the granular reticular sub- 

 stance may still be found usually lying in contact with the walls 

 of the air-spaces. Its presence here indicates how the fetal liquid 



Fig. f) Lung of albino rat, onc-lialf hour after birth, showing partial expan- 

 sion. X 25. 



is disposed of when breathing commences. When the lung ex- 

 pands and the fluid in trachea and bronchi is drawn downward, 

 part of the fluid remains adherent to the inside of the walls. 

 In many sections it appears that more of the gi-anular ))i-ecipitate 



