THE FROG 



CHAP. 



cutaneous and gastric glands is the same, the manufactured 

 article is entirely different in the two cases. Each kind of 

 gland-cell has the faculty of picking and choosing, the 

 material supplied being worked up in the one case into the 

 cutaneous secretion, in the other into gastric juice. 



l.7Tt 



FIG. 40. A, part of a transverse section of the frog's stomach ; B, one of the gastric 

 J glands in longitudinal section, highly magnified ; C, transverse section of a 



gastric gland. 



b. r'. blood-vessel ; c. cavity of gastric gland ; c. in. circular muscles ; c. in. m. 

 circular layer of muscularis mucosse ; ep. epithelium ; g. gl. gastric glands ; 

 /. ///. longitudinal muscles ; /. in. in, longitudinal layer of muscularis mucosae ; 

 ;//. mouth of gastric gland ; mi. nucleus ; pr. peritoneum ; s. in. submucosa., 



The submucosa of the stomach is traversed by a narrow 

 band of unstriped muscle, the muscularis mucoscc, formed, 

 like the main muscular layer, of an outer layer of longitudinal 

 (/.;;/.;;/) and an inner of circular (c.m.m) fibres. 1 



1 A very thin muscularis mucosoe is also present in the intestine 

 (compare Fig. 39, B). 



