g6 Vertebrata. 



partments, and into the first of these (called the 

 paunch} the food is taken when first swallowed ; then 

 it passes into the second division, which consists oi 

 many large hexagonal cells or little chambers ; here 

 it becomes divided into masses for re-chewing, and 

 these pass up the oesophagus back into the mouth, 

 where it is carefully and slowly masticated, and mixed 

 with saliva, after which it is re-swallowed, but this time 

 as a semi-fluid soft material, which on reaching the 

 stomach is conducted along a gutter made by a 

 mucous fold, into the third stomach or liber, which 

 consists of many layers of mucous membrane arranged 

 like the leaves of a book. Here the materials are still 

 farther mixed up with the secretions of gastric glands, 

 and pass on into the fourth stomach, where digestion 

 finally takes place. The camels of Arabia and Africa 

 differ from the other ruminants in having no third 

 stomach, in possessing canine teeth in each jaw, and 

 two lateral incisor teeth in the upper jaw. They have 

 also nails rather than hoofs on their large and well- 

 padded toes. The hump on the camel's back consists 

 of fat and cellular tissue. There is a single hump on 

 the dromedary, but there are two on the back of the 

 Arabian or Bactrian camel. The second stomach of 

 the camel has deep cells or compartments, which has 

 given origin to the fables about the capacity of camels 

 to store water in their stomachs. 



The llamas of the Andes in South America are 

 closely allied to the camels, and agree with them in 

 most of their peculiarities, but have no humps. The 

 musk-deer, which inhabit the mountainous regions 

 between the Himalaya and the Altai mountains, have 



