FOOD AND DIGESTION. 355 



deepest set of fibres, are the oblique, continuous with the circular mus- 

 cular fibres of the oesophagus, and having the same double-looped ar- 

 rangement that prevails in the preceding layer: they are comparatively 

 few in number, and are placed only at the cardiac orifice and portion of 

 the stomach, over both surfaces of which they are spread, some passing 

 obliquely from left to right, others from right to left, around the cardiac 

 orifice, to which, by their interlacing, they form a kind of sphincter, 

 continuous with that around the lower end of the oesophagus. The 

 muscular fibres of the stomach and of the intestinal canal are unstmated, 

 being composed of elongated, spindle-shaped fibre-cells. 



(3) and (4) The mucous membrane of the stomach, which rests upon 

 a layer of loose cellular membrane, or sulmucous tissue, is smooth, 

 level, soft, and velvety; of a pale pink color during life, and in the con- 

 tracted state thrown into numerous, chiefly longitudinal, folds or rugae, 

 which disappear when the organ is distended. 



The basis of the mucous membrane is a fine connective tissue, which 



Fig. 250. Transverse section through lower part of peptic glands of a cat. a, peptic cells; &, small 

 spheroidal or cubical cells; c, transverse section of capillaries. (Frey.) 



approaches closely in structure to adenoid tissue; this tissue supports 

 the tubular glands of which the superficial and chief part of the mucous 

 membrane is composed, and passing up between them assists in binding 

 them together. Here and there are to be found in this coat, immedi- 

 ately underneath the glands, masses of adenoid tissue sufficiently 

 marked to be termed by some lymphoid follicles. The glands are sepa- 

 rated from the rest of the mucous membrane by a very fine homogene- 

 ous basement membrane. 



At the deepest part of the mucous membrane are two layers (circu- 

 lar and longitudinal) of unstriped muscular fibres, called the muscularis 

 mucosce, which separate the mucous membrane from the scanty sub- 

 mucous tissue. 



When examined with a lens, the internal or free surface of the stom- 

 ach presents a peculiar honeycomb appearance, produced by shallow 

 polygonal depressions, the diameter of which varies generally from ^th 

 to ^th of an inch (about 125/*) ; but near the pylorus is as much as 

 -rbthof an inch (250,u). They are separated by slightly elevated 

 ridges, which sometimes, especially in certain morbid states of the stom- 

 ach, bear minute, narrow vascular processes, which look like villi, and 



