URINAEY APPARATUS. 197 



ules (renal epithelia) is an exception under these conditions. 

 Marked increase of epithelial cells is due to a pathological 

 desquamation, hence is observed in catarrhs and inflammation 

 of the membranes concerned. It is important to 

 be able to recognize the origin of the 

 cells by their form. 



Renal epithelium is roundish or more or less 

 cubical and granulated with proportionately large granules 

 and is much smaller than the pavement epithelium of 

 the pelvis of the kidney, the urethra and the bladder. They 

 occur singly or several united and not infrequently show signs 

 of fatty degeneration. Their occurrence indicates a renal 

 affection, but whether or not inflammation exists must be de- 

 termined by further examination of the urine. 



Pavement epithelia from the pelvis of the 

 kidney, the urethra and the bladder resemble each other and 

 cannot be distinguished as to their particular source. They 

 are large, flat, polygonal, transparent, nucleated pavement 

 cells. Those coming from the surface layers of the mucous 

 membrane are more roundish or polygonal, those from the 

 deeper layers are more oval, or cone shaped and may contain 

 one or more protoplasmic projections that give them a toothed 

 appearance. If a considerable number of such cells are pres- 

 ent a catarrhal condition of the corresponding mucous mem- 

 branes is indicated. 



h. White blood corpuscles or pus cocci are spherical, 

 granulated, nucleated cells that are cleared or become trans- 

 parent when treated with acetic acid. They may have come 

 from the kidneys or from the urinary tract; if from the kid- 

 neys we also find casts, if they occur simultaneously 

 with numerous pavement epithelia and crystals of triplephos- 

 phate they come from the bladder. 



