24 HUMAN PHYSIOLOGY 



at right angles to their plane of attachment, and become 

 columnar in shape. The free border of the cells looks like 

 a hem, an appearance which is due to a series of short rods 





Fio. 5. (a) Columnar Epithelium from the small intestine; (b) Ciliated 

 Epithelium from the trachea. 



placed side by side. Probably this is a special development 

 of the reticulum of the protoplasm. The great function of 

 this form of epithelium is to take up the digested matter 

 from the stomach and intestine, and to pass it on to the 

 blood. 



Among these columnar cells a certain number of peculiarly 



Fio. 6. A Zymin-secreting Gland, to show duct and acinus lined with secreting 

 cells containing zymogen granules. 



modified cells, chalice cells, are always found. They are 

 larger than the columnar cells, and somewhat pear-shaped, 

 being attached by their small extremity. Their protoplasm 



