64 Ciliated Columnar Epithelium. 



With a high power the network in the cells and their 

 nuclei will be seen as depicted in the Atlas. 



Make a longitudinal section of the large intestine of cat, 

 dog or rabbit, prepared in chromic acid mixture, stain with 

 logwood, mount in Canada balsam, and examine. The 

 columnar cells will be seen in rows, some of them having 

 become goblet shaped, that is distended by their secre- 

 tion, and if the animal has been killed some time after 

 feeding, when digestion is going on, these goblet cells 

 will stain deeply with logwood, and the mucin will be 

 seen poured out from the cell in deeply-stained masses. 

 If, however, the animal has been killed within a short 

 time of feeding, that is before the mucigen has been 

 changed into mucin ; these goblet cells will not stain 

 with logwood but will stain with anilin colours. 



CILIATED COLUMNAR EPITHELIUM. 



Take a portion of the trachea of cat, prepared in 

 2 per cent, solution of bichromate of potash, wash well 

 in water, and stain the mass in logwood ; it must be 

 put in a strong solution and left in for several hours ; 

 when deeply stained remove it, wash well until no more 

 colouring matter comes away. Then with a small 

 knife scrape away a little of the inner surface, and 

 place it in a very small drop of glycerine on a slide, 

 pound it with the rounded end of a needle holder until 

 the whole drop is seen to be permeated with fine par- 

 ticles, and no large ones are left ; place the cover glass 

 on gently and allow the fluid to spread under it ; seal 

 and examine. 



