FORMATION OF HYDROCHLORIC ACID IN THE FOVEOUE. 243 



If the staining has progressed far enough the edge of the prepara- 

 tion may be teased with needles and the superficial glands which 

 alone are stained so isolated, when a cover glass is applied and 

 the preparation studied by high power objectives. For these 

 experiments we have used rabbits, guinea pigs, cats, and dogs. 



In such preparations certain cells scattered throughout the 

 glands promptly stain blue, the blue color affecting not only 

 the protoplasm but the nucleus. These belong to both classes 

 of cells constituting the glands and are interpreted by us as dead 

 cells. In addition the small cells, first described by R. Heiden- 

 hain, which occur in small numbers scattered among the other 

 epithelial cells of the gland, and the nature of which is still 

 obscure, stain blue, but in this case the blue stain is confined to 

 the granules with which the protoplasm of these cells is studded, 

 the nucleus remaining unstained. Certain glands on the very 

 edge of the preparation may stain bluish red, these being for 

 the most part glands which have been actually injured in making 

 the preparations. 



In the uninjured glands reached by the dye, on the contrary, 

 a uniform and characteristic reaction is obtained. With the 

 exception of the dead cells and the small cells of Heidenhain men- 

 tioned above, the dye is entirely confined to the secretion in the 

 lumina of the glands and their various diverticula, including the 

 whole basketwork of canaliculi in the parietal cells all of w r hich 

 was intensely stained. Moreover, in no place in this system of 

 gland tubules below r the level of the gastric foveolse was the blue 

 color of the acid solutions of the dye obtained. On the contrary 

 the secretion contained in the canaliculi of the parietal cells was 

 a distinct red like that displayed by the dye in alkaline solutions, 

 while the secretion in the lumen of the gland was a bluish red. 

 The short canaliculi connecting the parietal cell system of intra- 

 cellular channels with the main lumen of the gland showed a 

 color shading from the red of the content of the latter to the 

 bluish red of the contents of the gland lumen. At the level of 

 the bottoms of the foveolse the color of the secretion changed 

 rapidly to the pure blue of the acid solutions of cyanamin, and 

 the cylindrical cells of the surface and of the foveolae stained the 

 acid color also. 



