326 



OF DIGESTION AND NUTRITIVE ABSORPTION. 



[Fig. 80. 



A view of the Organs of Digestion, opened in nearly their wholg length ; a portion of the O3sophagus has 

 been removed on account of want of space in the figure; the arrows indicate the course of substances along 

 the canal ; 1, the upper lip, turned off the mouth ; 2, its frsenum; 3, the lower lip, turned down ; 4, its frsenum ; 

 5, 5, inside of the cheeks, covered by the lining membrane of the mouth; 6, points to the operting of the duct 

 of Steno; 7, roof of the mouth; 8, lateral half arches; 9, points to the tonsils; 10, velum pendulum palati; 

 11, surface of the tongue; 12, papillae near its point; 13, a portion of the trachea; 14, the oesophagus; 15, 

 its internal surface; 16, inside of the stomach; 17, its greater extremity or great cul-de-sac; 18, its lesser 

 extremity or smaller cul-de-sac ; 19, its lesser curvature ; 20, its greater curvature ; 21, the cardiac orifice ; 

 22, the pyloric orifice; 23, upper portion "of duodenum; 24, 25, the remainder of the duodenum; 26, its 

 valvulse conniventus; 27, the gall bladder; 28, the cystic duct; 29, division of hepatic ducts in the liver; 

 30, hepatic duct; 31, ductus communis choledochus; 32, its opening into the duodenum; 33, ductus Wir- 

 sungii, or pancreatic duct; 34, its opening into the duodenum; 35, upper part of jejunum; 36, the ileum; 

 37, some of the valvute conniventus; 38, lowej extremity of the ileum ; 39, ileo-colic valve ; 40, 41, caecum, 

 or caput coli ; 42, appendicula vermilbrmis ; 43, 44, ascending colon ; 45, transverse colon ; 46, 47, descend- 

 ing, colon; 48, sigmoid flexure of the colon ; 49, upper portion of the rectum; 50, its lower extremity; 51, 

 portion of the levator-ani muscle ; 52, the anus.] 



bile, like the gastric juice, is secreted in the walls of the stomach ; as may be 

 distinctly perceived in many of these animals, on account of their transparency, 

 and the bright yellow colour of the fluid. As we ascend the animal series, 



