94 Mammalia. Digestive System. 



genital canals all terminate within a common external outlet ; so 

 that in the literal sense the Marsupialia are monotrematous. 



Monotremata. The rectum terminates at the anterior and dorsal 

 part of the vestibular compartment of the Cloaca. 



19. The Great Oraentum 



is small, and does not cover the Intestines 

 in Prohosciclia^ Perissodactijla, and Sirenia. 



20. The Liver 



is simple 



in Bimana and Cete. 



is Multifid, to a greater or less degree in 



most other Orders, the average being seven to eight lobes. 



Rodentia. In Capromys each lobe is subdivided into almost in- 

 numerable angular lobules, which, though closely in contact, are quite 

 detached from each other, being appended by their apices to the 

 large branches of the vena portse and hepatic arteries and veins. 

 Each of the lobules is partially subdivided into still smaller ones, 

 the whole structure approximating to a complete natural unravel- 

 ling of this conglomerate gland to its component acini. 



Ungulata. The Liver is least subdivided in the purely herbivor- 

 ous Ungulates. The Perissodactyles have in general a larger and 

 more subdivided Liver than the Artiodactyles, especially than the 

 Euminants, in all of which (E.) the Liver is confined to the right 

 hypochondriac (vtto, under; xpydpog, cartilage, of ribs), and epigastric 

 (7ri on ; yaarrjp the stomach) regions. 



Marsupialia. The Liver is subdivided into many lobes in all ; 

 but especially in Koala, where the under surface is subdivided into 

 thirty or forty lobules. 



21. The Gall Bladder 



is absent in 



some Cheiroptera, e.g. Roussettes and Colugos ; 



some Rodentia J e.g. Mus, Cricetus (Hamster), and Helamys (Jerboa); 



the Prohoscidia, where however the hepatic duct is wide and 

 very long, with a reticulate inner surface, and expands between the 

 coats of the duodenum into an oval receptacle, irregularly divided 

 into compartments ; 



all Perissodactyla ; 



some Artiodactyla, e.g. Camelidce and Cervidse ; 



