20 



epithelium of an Amphibian (Necturus, Amblystoma. Frog). 

 Demonstration. Note the short cilia projecting up from the flat- 

 tened cells of the peritoneal epithelium. 



PAVEMENT EPITHELIUM. 



14. Peritoneal epithelium (endothelium). Mesentery of 

 cat. Assigned for study. The fresh mesentery was treated with a 

 YZ% aqueous solution of silver nitrate, washed in water, exposed to 

 sunlight until the cell- cement between the cells had blackened, 

 washed in water, stained in hematoxylin to bring out the nuclei, 

 dehydrated, cleared and mounted in balsam. 



Study the preparation, noting the nuclei and cell-outline as 

 indicated by the stained cell cement. Remember that the cells are 

 flat and a single layer deep. 



(13). Ciliated pavement (peritonea 1 !) epithelium. Dem- 

 onstration. See 13 above. 



STRATIFIED EPITHELIUM. 



(10). Stratified epithelium. Vertical section. Assigned for 

 study. The oral side of the soft palate is covered with a stratified 

 epithelium. 



Note the shape of the cells and nuclei in the deeper layers and 

 compare with the cells of the superficial layers, observing the grad- 

 ual transition as you pass from the deepest to the superficial cells. 

 Are intercellular bridges to be seen ? 



15. Stratified epithelium ; surface cells. With the 

 finger nail gently scrape the inside of your own cheek and mount 

 the scrapings on a slide, adding a drop of normal salt solution if 

 necessary. Examine the preparation, noting the shape and size of 

 the epithelial scales, the shape and size of the nucleus. The sur- 

 face of the cells may be marked by ridges where neighboring cells 

 have overlapped. Can you find groups of two or more cells? 



Compare with the superficial cells of 10 where you see them in 

 section, or on edge. 



1 6. Stratified epithelium ; deeper cells. Isolated cells 

 from the deeper layers of the epithelium of the lip. W-* 



Miiller's fluid dissociator ; stained with ; now in 



Mount in glycerin jelly. In studying this preparation find 



