XXIV.] 



THE STOMACH. 



269 



apart, the interval between any two being occupied by the inner or 

 central cells. The parietal cells are deeply stained by aniline-blue 

 and carmine, and osmic acid, while in a logwood-stained section the 

 inner cells are usually more deeply stained. 



Observe a continuous layer of cells inner, central, or chief 

 lying internal to the parietal cells. They are smaller, and belong 

 more to the columnar type of cell, but they are not of uniform height 

 throughout ; thus they are shorter over a parietal cell, and larger 

 between two parietal cells. Each cell contains a spherical nucleus. 



The lumen of the gland-tube is very 

 narrow. The secretory part is much longer 

 than the duct. 



(fj.) Arrange the preparation so that the 

 lower ends of the glands come into view. 

 Note their closed extremities, and if the 

 granular epithelium have shrunk somewhat, 

 the basement membrane of each gland-tube 

 may be seen ; very probably transverse or 

 oblique sections of the lower part of the 

 gland will be found (lig. 257). 



(It.) At the bases of the gland-tubes, but 

 outside their basement membrane, note the 

 delicate connective tissue or adenoid tissue, 

 with a number of leucocytes. If the section 

 be from a cat's stomach, a clear homogene- 

 ous layer runs outside this. 



(i.) Outside this the muscularis mucosaB 

 composed of at least two layers of non-striped 

 muscle arranged in opposite directions. 

 Especially in a balsam specimen, fine strands 

 of muscular fibres are always to be seen 

 passing from the muscularis mucosa3 in- 

 wards towards and between the glands, 

 t'sually these fine strands pass inwards 

 between groups of glands. In the osmic 

 acid preparations, the parietal cells are much 

 darker than the central cells. 



(./.) There is nothing particular to note in the structure of the 

 other coats. 



2. T.S. Fundus Glands. Make a section parallel to the surface 

 of the mucous membrane, stain with logwood, or picro-carmine and 

 aldehyde-green, or use an osmic acid preparation. 



(H) Observe that all the gland-tubes are not cut at the same 

 level ; some are divided through the duct, others through the 

 secretory part of the tube. In the latter observe the large parietal 



FlO. 257. V.S. Mucous Mem- 

 brane of the Stomach, Cat. 

 Osmic acid. 



