ANATOMICAL STEUCTURE OF THE SHEEP. 97 



■svhich it was first expelled, only to be again pumped out and 

 sent on its mission through the system. The abdomen contains, 

 as has been mentioned, the stomachs, liver, intestines, kidneys, 

 bladder, and other organs, where the functions of digestion are 

 carried on, and where various fluids are manufactured for or 

 excreted from the system. We find that the internal organs are 

 not firmly fixed in the different cavities, but are suspended as 

 it were from the roof of these chambers by a membrane, en- 

 dowed with nerves and blood vessels, called respectively: the 

 pericardium, as it envelopes the heart; the pleura, as it invests 

 the lungs, and the peritoneum as it suspends and covers the stom- 

 achs, liver, intestines, and other parts in the abdomen. The 

 part of the peritoneum suspending the large and small intestines 

 is called the mesentery, and contains within its folds nerves, 

 blood vessels, and glands, connecting with the circulation of the 

 blood supply of the absorbent glands of the bowels, called villi. 

 These glands in the mesentery are called lacteals, they absorb 

 the products of digestion, called the chyle, and convey it away 

 to a duct or canal called the thoracic duct, which enters the cir- 

 culation near the point of entrance of the venous blood to the 

 heart. It is the chyle in the blood which furnishes niitriment 

 to the various tissues, and is of vital importance in repairing the 

 incessant waste of the tissues. We shall consider the functions 

 of the liver and other organs of the body when describing the 

 respiratory and digestive organs of the body. 



The Skeleton of the Sheep is an aggregation of bones possess- 

 ing stability and firmness for the attachment of muscles, and the 

 protection of the vital organs situated in the chest and ab- 

 dominal cavities. 



Bones are composed of inorganic salts deposited in a basis 

 of animal matter; to the former it owes its hardness and density, 

 to the latter its elasticity and tenacity, the combination of the 

 two rendering the tissue solid and elastic enough to prevent 



