KIDNEYS, SKIN, AND GENERAL EXCRETION. 



387 



.r, and an inner layer, whitish, revealing numerous glis- 

 tening threads running towards the pelvis of the kidney. 

 This second area is called the medulla. Between the cor- 

 tex and the medulla the main blood-vessels of the kidney, 

 both arteries and veins take their course. The interior of 

 the kidney is hollow, and is called the pelvis. This pelvis 

 connects with the ureter, by means of which duct the se- 

 cretion is carried to the bladder. The medulla breaks in 

 the pelvis into several (five to ten) pyramidal projections, 

 called the pyramids of Malpighi. At the ends of these 



Fijf. 128. DIAGRAMMATIC SECTION THROUGH PART OF KIDNEY PARALLEL TO TUBULES. 



(After Testut.) 



ff, papilla; b, medulla; c, cortex; 2, capsule; 3, tubules in medulla; 4, blood-vessels; 

 9, Malpighian corpuscles. 



pyramids numerous uriniferotis tubules open into the pelvis. 

 The depressions between the pyramids are called the 

 calyces. 



