90 Mammalia. Digestive System. 



sacculated along the line of the greater curvature, by means of 

 a pair of strong muscular bands, like the human Colon. 



Marsiipialia. In Macropus (Kangaroo) the sacculated Stomach re- 

 sembles the human colon, both in its longitudinal extent, structure, 

 and disposition in the abdomen ; three narrow longitudinal bands of 

 muscular fibres extend the whole length, except near the Pylorus j 

 the cardiac extremity is bifid, or subclavate. 



15. The Small Intestine. 



Dilatation of the Duodenum, 



Rodentia. The Intestinal Canal usually begins by a well-marked 

 dilatation. In Coypu this dilatation is so large that it projects 

 towards the GEsophagus, like a Cajcum : the whole Duodenum is more 

 continuously and loosely suspended than in most higher Mammals. 



Perissodactyla. Commencing from the Pylorus, the Duodenum 

 is considerably dilated, but its diameter soon contracts. 



Artiodactyla. The Duodenum is always dilated at its commence- 

 ment ; it there forms a distinct pouch in the Camel. 



Cete. The Duodenum always commences by so considerable a 

 dilatation that it has been sometimes reckoned among the divisions 

 of the complex Stomach. 



In-Miamellata. In Dasypus the Duodenum is dilated at its com- 

 mencement. 



Marsupialia. In Phascolarctos the Duodenum commences with a 

 small pyriform sacculus, nearly an inch in breadth, but soon con- 

 tracts to a diameter of five lines, which is the general calibre of 

 the small Intestines. 



Mucous Lining y Villi, Folds, Glands, &c. 



JBimana. The surface of the Mucous Membrane is extended by 

 transverse folds, or valvulse conniventes, in the Jejunum and Ileum ; 

 where also are to be found, situated opposite the line of attachment 

 of the mesentery, numerous patches of ' agminate follicles.' 



Insectivora. As a rule, the Intestinal Canal is uniform in diame- 

 ter, and devoid of Csecum. The lining membrane of the intestine 

 of Talpa is disposed along part of the canal in close-set longitudinal 

 folds; but is remarkable for its smoothness, and the absence of 

 visible Yilli. 



Frohoscidia. The termination of the Ileum projects as a conical 

 valve into the CfEcum. The mucous coat of the Jejunum is throwa 

 into small irregular folds, both transverse and longitudinal. 



