KIDNEYS. 



77 



The Uriniferous Tubules. Tr/e kidney is a compound tubular gland 

 composed of microscopic tubules, whose function it is to secrete from the 



FIG. 9. 



LONGITUDINAL SECTION THROUGH THE KIDNEY, THE PELVIS OF THE KIDNEY, AND A 

 NUMBER OF RENAL CALYCES. 



A, branch of the renal artery; U, ureter; C, renal calyx; i, cortex; i', medullary 

 rays ; i", labyrinth, or cortex proper ; 2, medulla ; 2', papillary portion of medulla, 

 or medulla proper; 2", border layer of the medulla; 3, 3, transverse section through 

 the axes of the tubules of the border layer ; 4, fat of the renal sinus ; 5, 5, arterial 

 branches ; *, transversely coursing medulla rays. Tyson, after Henle. 



blood those waste products which collectively constitute the urine. If the 

 apex of each, pyramid be examined with a lens, it will present a number 



