EXCRETION AND THE EXCRETORY ORGANS 



523 



Lobule. 



Lobule. 



Arched col- 

 ecting tubule. 



Descending 

 limb. 



Collecting 

 tubule. 



Papillary duct. 



Tunica fibrosa 



Stellate vein. 



Interlobular 



artery. 



Interlobular 



vein. 



Arcif orm artery. 

 Arciformvein 



Interlobar artery. 

 Interlobar vein. 



Fia. 140. ^Diagram of kidney tubule and renal blood-vessels (Lewis and Stohr). 



