URINARY APPARATUS. 



199 



Epithelial 



Casts. 



Fie-«- 2. Epithelial casts consist of renal epithelia 



agglutinated with exudates and forced out of the 

 tubules by the pressure of the 

 urine above them. Frequently Fig. 49. 



red and white blood corpuscles 

 are associated with them. Such 

 cylinders, providing they occur 

 in any appreciable numbers, al- 

 ways indicate inflammation of 

 the kidneys. These epithelial 

 cells may also have undergone 

 fatty degeneration. If they con- 

 tain no cells they are Called Granular Casts. 



granular casts, and have the 

 same significance as the epithelial cylinders. 



3. Blood corpuscle casts are formed of agglutinated red 

 corpuscles and are due to renal hemorrhage. If these casts 

 contain many white corpuscles they indicate purulent inflam- 

 mation (pus-casts). 



1. Examination for micro-organisms is of value in 



case of fresh urine only, because urine that has been standing 



for some time will soon become filled with great masses of 



bacteria and mold fungi from the air. Large numbers of 



bacteria in fresh urine occur in pyelonephritis bacteritica and 



in chronic cystitis. 



Bacillus pyelonephritis bovis will stain according to Gram's 

 method. A cover glass preparation is made from the sediment 

 of the urine, stained with gentian violet, rinsed with water, a few 

 drops of Lugol's solution (Iod. 8, Pot. Iod. 4, Aqua 100) added, 

 then decolorized in alcohol. All bacteria that stain according to 

 Gram's method have now assumed a deep blue color; while all 

 the rest are decolorized. Bac. pyeloncph. appears as a rod with 

 rounded ends, 2-3u long and 0.7u in diameter, evenly stained and 

 usually occurring in little groups. 



III. Examination of the Urinary Organs. 



Topography. In the horse and cow the leftkid- 

 ney only is accessible for palpation from the 

 re c t u m , the right kidney lies further forward and cannot be 



