CILIATED COLUMNAR EPITELIUM. 45 



Place a piece of the gut on a slide and, after having added a drop 

 of the acid solution, scrape off the mucous surface with a knife and 

 remove the remainder of the gut. Add a cover-glass and focus H. 

 You will find cells in various conditions, from isolated examples to 

 small groups like Fig. 28. 



FIG. 28. COLUMNAR CELLS FROM SMALL INTESTINE OF RABBIT. 



A. Tapering attached extremity. 



B. A swollen goblet cell. 



C. Finely striated free border. 



D. Transparent line of union between the striated portion and the body of the cell. X 400. 



Observe that the attached ends of the cells are often small and 

 pointed, and that spheroidal and ovoidal cells are frequently wedged 

 in between them. Note the -free border : It consists of striae, and is 

 separated from the body of the cell by a translucent line. This ap- 

 pearance is also that of the epithelium in the human intestine. 



Ciliated Columnar Epithelium. 



Prepare, by scraping, a slide from the mucous surface of the pig's 

 bronchus (which has been macerating in the chromic acid). 



Observe the cilia on the free border of the cells. Interspersed be- 

 tween ciliated cells, much enlarged individuals may be found, the so- 

 called beaker, goblet or mucous cells. 



The motion of the cilia may be demonstrated as follows : 



Carefully open an oyster so as to preserve the fluid. On examina- 

 tion you will notice the leaflets, shown in Fig. 30, commonly called 

 the beard. With the scissors snip off a fragment. of the free border of 



