CAMELID^. 247 



of a somewhat square form, with two well-marked constrictions. The 

 second stomach, small and globular, is situated between the paunch and 

 the third stomach, and appears to be a sort of terminal dilatation of the 

 oesophagus. It is called the reticulum, or honeycomb-bag, being lined 

 with polygonal acute-angled cells. The third stomach, the manyplies of 

 the Scotch, is small and sub-globular, but is much increased in capacity 

 internally by the folding of the lining membrane. The fourth stomach is 

 the true digestive sac, about one-third of the size of the paunch, and of 

 an elongated pyramidal form. The intestinal tube is very long, and the 

 lai'ge intestines are very much wider than the small ones. The caecum is 

 bulky, smooth, and obtuse. The liver is simple, and there is a gall-bladder 

 in all except in the Cervidce. The urinary bladder is large ; the testes 

 are enclosed in a scrotum ; and the mammte are inguinal, with two to 

 four teats. Many are provided with a hollow gland below the eye, 

 called the eye-pit, tear-pit, lachrymal, or infraorbital sinus. Tliis 

 secretes a waxy sort of substance, — in some of the tribe it is very 

 mobile, and can be opened at pleasure, or even reversed. Its use is 

 not exactly ascertained, but it is generally considered subservient to 

 sexual purposes. Many also possess hollow inguinal glands, or groin-pits. 



Ruminants form five groups, — Camelidce, Camelopardidce, Moschidce, 

 Cervidce, and Bovidce. 



Camels, Camelidce, forming the Ancerata of Blyth, have a cleft upper 

 lip, which is prehensile, two toes encased in skin, with nail-like hoofs, and 

 the whole surface of the toes touches the ground. They have two upper 

 incisors, and six in the lower jaw, and two canines in each jaw. They have 

 usually 18 to 20 molars, there being generally one more molar above on 

 each side than in the lower jaw. In the true camels, the foremost molar 

 is placed considerably in advance of the others. This family includes the 

 Camels of the old world, and the Alpacas of the new world. The former 

 have the two toes united below almost to the jDoint by a common sole, and 

 humps of fat on the back. Two species are known, both of lai'ge size, 

 Camelus dromeda/riiis, L., the one-humped camel or dromedaiy ; and the 

 two-humped, or Bactrian camel, C. bactrianus, L. They are now com- 

 pletely domesticated. The former is supposed to have spread from Arabia 

 into North Africa, India, &,c. ; the latter is considered to have spread 

 from Central Asia. Their humps are reservoirs of fat, which become ab- 

 sorbed during long fasts, and enable them to take long journeys on very 

 little food. Their flat feet are admirably adapted for treading on loose sand. 



