TISSUES. 



59 



ing drop. The cytoplasm and nucleus are crowded 

 to the opposite end. In serous cells the nucleus is 

 more centrally placed, and the serous secretion is 

 stored up as minute granules distributed through- 

 out the cytoplasm, more especially in that por- 

 tion of the cell lining the free surface. Some 



Crypt. 



Chief cell. 



Fig. 25. Simple tubular gland from stomach. 



glands are mucous, some are serous, and some are 

 mixed. 



Mucous Membrane. A mucous membrane con- 

 sists of a lining of epithelial cells, basement mem- 

 brane, and membrane propria. The basement mem- 

 brane is largely an elastic cellular secretion on which 



