THE KIDNEY 



179 



the cortical portion there appear a number of pyramidal masses- 

 whose apices we have previously seen of finely striated texture 

 the medullary or Malpighian pyramids. The cortical substance 

 projects itself between the pyramids, completely isolating them, 

 and forming the cortical columns of Bertini. 



Again observing the outer cortex, it will present narrow, light- 



Capsule of the organ 



Pyramids of Ferrein 

 Cortical labyrinths 



Renal arterial^ 

 branches 



Arterial arcade branches 



Interlobular arteries 



FIG. 115. DIAGRAM SHOWING THE PLAN OF STRUCTURE OF THE HUMAN KIDNEY. 



colored lines, which converge toward the pelvis ; and, eventually, 

 pass into and become a part of the Malpighian pyramids. These 

 light areas, made up of tubules, are the pyramids of Ferrein, or, 

 as sometimes called, the medullary rays. 



The darker spaces between the pyramids of Ferrein are called 

 labyrinths. 



The gross elements, to be understood before we proceed any 

 further, then, are .- 



