ISO NORMAL HISTOLOGY. 



Scattered here and there between the cylindrical 

 epithelium, sometimes abundant, sometimes not, 

 are transparent more or less ovoidal cells with a 

 nucleus and a small amount of protoplasm in the 

 vicinity of the narrow base ; they look as if the 

 free border of the cell had fallen off and most of 

 the cell-contents had disappeared. Not infre- 

 quently a translucent structureless substance is seen 

 protruding from the open end of the cell, as if in 

 the act of passing out of it. These cells are called, 

 from their form, goblet-cells. Their significance is 

 not yet definitely determined in all cases : by some, 

 they are regarded as cylindrical cells changed by 

 artificial means ; but most observers believe them 

 to be normal structures, and suppose that under 

 certain circumstances the cell-contents undergo a 

 mucous metamorphosis, swell up, burst out of the 

 cell, leaving little but the membrane and nucleus 

 behind, and that thus, under normal conditions, a 

 certain amount of the mucus furnished by mucous 

 membranes is produced. 



In addition to the tubular glands which are found 

 throughout the whole extent of the small intestine 

 in the duodenum, especially in its upper por- 

 tions racemose, probably mucous glands, are 

 found, called Brunners glands. They lie in the 

 submucosa, and consist of variously shaped, but 

 usually elongated alveoli, surrounded by a mem- 

 brana propria and lined with cylindrical epithelium. 



