274 DIGESTION. 



oesophagus, and spread out in a diverging manner over the 

 great end and sides of the stomach. They extend as far 

 as the pylorus, being especially distinct at the lesser or 

 upper curvature of the stomach, along which the} 7 pass in 

 several strong bands. The next set are the circular or 

 transverse fibres, which more or less completely encircle 

 all parts of the stomach ; they are most abundant at the 

 middle and in the pyloric portion of the organ, and form 

 the chief part of the thick projecting ring of the pylorus. 

 According to Pettigrew, these fibres are not simple circles, 

 but form double, or figure-of-8 loops, the fibres intersecting 

 very obliquely. The next, and consequently deepest set of 

 fibres, are the oblique, continuous with the circular mus- 

 cular fibres of the oesophagus, and, according to Pettigrew, 

 with the same double-looped arrangement 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 fibres of 

 which the several muscular layers of the stomach, and of the 

 intestinal canal generally, are composed, belong to the class 

 of organic muscle, being composed of smooth or unstriped, 

 elongated, spindle-shaped fibre cells; a fuller description 

 of which will be given under the head of Muscular Tissue. 

 The mucous membrane of the stomach, which rests upon 

 a layer of loose cellular membrane, or submucous tissue, is 

 smooth, level, soft, and velvety ; of a pale pink colour 

 during life, and in the contracted state is thrown into 

 numerous, chiefly longitudinal, folds or rugae, which dis- 

 appear when the organ is distended. When examined 

 with a lens, the internal or free surface presents a peculiar 

 honeycomb appearance, produced by shallow polygonal 

 depressions or cells (fig. 68), the diameter of which varies 



