AND PHYSIOLOGY. 



189 



the vegetable feeders having a long tube, and the flesh feeders 

 a short one, since animal food is so easy of stomach digestion, 

 and the nutrient portion of it so readily taken up by the 

 lacteals. Thus the ox has an alimentary tube fifteen or 

 twenty times the length of the body, amounting in a full 

 grown animal to 150 feet, the sheep one twenty-eight times its 

 length, while many of the carnivora exhibit one only about 

 three times the length of the body. The true Cetacea or Whale 

 tribe are the only ones which do not have a marked distinc- 

 tion between the large and small intestine. 



344. The Liver — The Liver as in man is one of the 

 largest organs in the body, and is much more divided into 

 lobes in carnivorous than herbivorous animals. It is smallest 

 and least divided in those animals with compound or rumi- 

 nating stomachs. 



345. Bill of Birds, — Birds are destitute of teeth, since 

 the process of mastication is carried on in a certain portion 

 of the alimentary canal. But the horny investment of the 

 jaws known as the bill, is harder in birds of prey, and those 



EiG. 193. 



Os Hyoides. 



Head of the Woodpecker. 



that feed on fruit and nuts, as Parrots, and in Woodpeckers. 

 The bill, or rather mouth, of Ducks and Geese is lined by 

 a tender membrane, in order that they may be partially 



What is the length of the Intestine of the Ox? Of the Sheep? Give the propor- 

 tional length of Intestine in Carnivorous Animals. 344. What difference in the Liver 

 between flesh and herbivorous animals ? 345. Why are Birds destitute of teeth ? 

 What Birds have the hardest bills? What peculiarity in the lining membrane of the 

 mouth of Ducks, etc. ? 



