40 MAMMALIAN GALLERY. 



T/agulina or Chevrotains, and (3) the Pecora, or the Oxen, Ante- 

 lopes and Deer, and the Giraffe. 



The molars of all these Mammals consist of two pairs of crescent- 

 shaped lobes, and their stomach is composed of four, or, rarely, 

 three divisions, from one of which their food is returned to their 



Fig. 15. 



Stomach of a Sheep, cut open to show the internal structure, 

 oe, oesophagus, or gullet ; ru, rumen, or paunch ; ret, reticulum, or honey- 

 comb ; ps, psalterium, or manyplies ; ab, abomasum j py, pylorus j du, 

 duodenum, the commencement of the small intestine. 



mouth after it has been swallowed, in order to be chewed a second 

 time, a process known as ruminating or chewing the cud. 



(1) The Tylopoda, the Camels and Llamas, are distinguished 

 from the other Ungulates by their elongate and prehensile upper 

 lip, their thick woolly fur, long neck and legs, two- toed feet, the 

 pads of skin beneath their hoofs (whence the name Tylopoda, or 

 " pad-footed "), their complicated stomach, whose walls contain a 

 peculiar set of large cavities, the so-called " water-cells " (supposed, 

 though with much doubt, to be for the purpose of storing water), 

 their oval blood -corpuscles (all other Mammals having round 

 ones), and by numerous other special characters. The first genus, 

 Camelus, contains the Dromedary and the Camel, both domesti- 

 cated, and ranging from North Africa, through Arabia, Persia, and 

 Central Asia, to India. The Dromedary, with one hump on the 

 back, is not known in a wild state ; while the two-humped Carnal 

 (C. bactrianus) has recently been discovered living in a wild state by 

 Russian travellers in the mountain-ranges of Central Asia. Even 

 these, however, are supposed by some authors to be the descendants 

 of domesticated individuals. The humps are large masses of fatty 

 substance serving as a store of nutriment, which during periods 

 of scarcity of food is gradually absorbed, and replenished when 



