ORGANIC CONSTITUENTS OF URINARY DEPOSITS. 691 



In the straight portion of the tubes it is flatter, and more like the 

 scaly variety. In the pelvis of the kidney, it is tessellated or 

 pavement-like, consisting of thin, flat scales united at their 

 edges. In the ureter it is columnar or cylindrical in shape, having 

 a large and distinct nucleus. In the fundus of the bladder colum- 

 nar epithelium is found mixed with large oval cells ; flattened 

 cells having a distinct nucleus and nucleolus abound in the trigone. 



Fia. 407. 



FIG. 408. 



Mucus, pus, blood, and epithelium from leucorrhcea. 



In the mucous follicles columnar epithelium is found; on the sur- 

 face between them, the scaly variety. The columnar variety pre- 

 vails in the posterior part of the urethra ; anteriorly it becomes 

 scaly. The vaginal epithelium found in the urine of females, is 

 also of the scaly variety. (Fig. 407.) 



Occasionally casts, consisting of moulds of the uriniferous 

 tubes, are observed in the urine. They furnish valuable aids in 

 arriving at a correct diagnosis 

 as to the pathological changes 

 which may be going on in the 

 kidney. They consist mainly 

 of oily granules, or epithelial 

 cells abundantly supplied 

 with these granules. (Fig. 

 408 A.) Pro Bennett divides 

 them into two distinct varie- 

 ties, namely, " 1st. Fibrin- 

 ous or exudation casts, which 

 are most commonly found in 

 the urine at critical periods 

 of acute inflammations, especially in scarlatina, small-pox, pneu- 

 monia, &c. 2d. Casts, with oily granules, indicative of chronic 

 disease, and especially of Bright's disease. (Fig. 409 4 .) At the 



