620 URO-GEN1TAL SYSTEM. 



Moreover, the lung becomes permeable and the ductus 

 arteriosus atrophied ; the blood from the right ventricle goes 

 directly to the lungs. Finally, the umbilical arteries are 

 obliterated by hypertrophy and retraction of their sides, and 

 are represented by the fibrous ligaments found on the walls 

 of the bladder ; the aorta carries the blood only to the limbs, 

 to the surface of the body, and to the vise era j the two 

 circles of the permanent circulation, with c< mplote inde- 

 pendence of each other, are then formed. 



