— 14 — 



Tliis ]if('i);iratioii j.Mve.s you a sui-face view of stratified 

 pavement epithelium. Ol^serve the flat nucleated cells, 

 cemented together 1)}' a small amount of intercellular 

 cement substance. Sketch a small portion of the fichl as 

 seen umlcr the high powci-. 



(d) Cross Section of Stratified Pavement Epithe- 



lium. 



A siiKill i)oi-Ui>u of the soft palate or tiie n'.-;oi)linirns was 

 lianli'iic'i in a satiirateil aqueous solution of incrcuric cliloii'lo or 

 absolute alcoliol, stained in l)oi-ax or alum carmine, emlx'dded in 

 panUIin, and sectione<l. Mount in balsam. 



Observe the several layers of epithelial cells, and their 

 change in shape as they are traced outwards. In the low- 

 est layer, the cells are columnar, in the following polygonal, 

 while in the outermost layers they are fltittened. Notice 

 the change in the shape and structure of the nuclei of the 

 cells of the different layers. Sketch as seen under high 

 i:)owor. 



(e) Isolated Transitional Epithelial Cells Stained 



in Heematoxylin and Eosin. 



The bhidder of a large dog was (distended witii '.Vo% alcoliol 

 before reniovinir, the uretlira was tied. The l)hulder was tiien phu-ed 

 in 33% alcoliol, where it remained 24 hours. It was then cut into 

 small pieces. Scrape the epithelial surface of one of the small 

 pieces, place the scraping on a cover glass, and tease thoronJ:hl\^ 

 After teasiui,' dry the prepartition over a ilanie. Stain in hiema- 

 toxylin and eosin, and mount on balsam. 



Examine under high power. Cells of various shapes 

 will be seen. Some are large flat scales with one or two 

 nuclei ; others are pear-shaped, spindle-sliaped, or triangu- 

 lar. The pelvis of the kidney, the ureter, and the bladder, 

 are lined with transitional epithelium. Sketch the several 

 forms of epithelial cells found. 



(f) Cross Section of Transitional Epithelium. 



Small pieces of the bladder of a doij; were hardened in al)-iO- 

 lute alcohol, stained for 24 hours in Delafield's li;eniatoxylin (one 

 part of the stain to ten parts of distilled water), embedded in 

 parafiln, and sectioned. Fix to the slide with allmmen fixative, 

 and mount in balsam. 



