328 



THE GENITOURINARY ORGANS. 



which, containing the nuclei, project into the lumen of the tubule. 

 These central projections of the cells are not directly opposite those 

 of the cells on the opposite wall, but alternate with the latter, thus 



Nucleus 



ON- -Nucleus. 



Fig. 264. Epithelium from proximal convoluted tubule of guinea-pig, with surface 

 and lateral views (chrome-silver method) ; X 59 : a > a > The irregular interlacing pro- 

 jections. 



iV^'-iP^* 1 -- 



-"*&- ^ 



Fig. 265. From cortical portion of longitudinal section of kidney of young child. 



giving to the lumen a zigzag outline corresponding to the length 

 of the cell. The thick portion of the loop, for the most part repre- 

 sented by the ascending limb, but generally embracing the loop itself, 



