CHAP. XXIV.] 



THE STOMACH. 



193 



and covering the surface of the membrane seem to be the altered 

 contents of these particles after their escape, for the uniform exist- 

 ence of a minute cavity in the centre of it, where it fills the cells, 

 shows that it has oozed out from every part of their wall, so as 

 gradually to fill them up (see fig. 155, A). 



Fig, 155. 



Fig. 156. 





Vertical section of a stomach cell, with its tubes : A. in 

 the middle region, B in the pyloric region. . Orifices of 

 the cells on the inner surface of the stomach, b b. Differ- 

 ent depths at which the columnar epithelium is exchanged 

 for glandular, c. Pyloric tube, or prolonged stomach cell. 

 d. Pyloric tubes, terminating variously, and lined to their 

 extremities with sub -columnar epithelium. 



From the dog, after twelve hours' fasting. Magnified 

 200 diameters. 



A. Horizontal section of a stomach cell, 

 a little way within its orifice, a. Basement 

 membrane. b. Columnar epithelium. 

 All but the centre of the cavity of the cell 

 is occupied by transparent mucus, which 

 seems to have oozed from the open extre- 

 mities of the epithelial particles, fi. Fi- 

 brous matrix surrounding and supporting 

 the basement membrane, d. Small blood- 

 vessel. 



B. Horizontal section of a set of sto- 

 mach tubes proceeding from a single cell. 

 The letters refer to corresponding parts, 

 The epithelium is glandular; the nuclei 

 very delicate; the cavity of the tubes 

 very small, and in some cases not visible. 



From the dog, after twelve hours' fast- 

 ing. Magnified 200 diameters. 



It has been said that the cells are so shallow as to dip into the 

 compound membrane only about -J-th of its thickness. The rest of 

 its thickness, except near the pylorus, is made up of minute tubular 

 offsets from the bottom of the cells, which may be termed the sto- 

 mach tubes (fig. 155, B; and fig. 156), and which pass vertically, two, 

 three, or four from each cell, afterwards subdividing again and again, 

 and becoming more or less tortuous, till they terminate by blind 

 extremities on a dense tough layer of areolar tissue continuous 



VOL. n. o 



