960 



Rural School Leaflet. 



moisture and is formed into long pellets. Later when the sheep "chews 

 its cud" these are forced back into the gullet and thence into the mouth. 

 There they are thoroughly masticated and re-swallowed. This time 

 the food does not stop at the opening into the rumen, but passes on 

 into the third stomach. The opening into the rumen from the oesophagal 

 canal is simply a slit which probably opens and closes auto- 

 matically, and does not respond to the food after its re-mastica- 

 tion. The food, on its way to the third stomach, passes the opening 

 to the second stomach, or reticulum. The reticulum serves as an aid to 

 the rumen. It is usually full of liquid, and may serve as a storage place 

 for water for immediate use, much as in the well-known case of the camel. 

 The third stomach is known as the omasum, or commonly, the "many 

 plies," on account of the large number of "leaves" which make up 

 its lining. Here the food gets its final squeezing and grinding until it is 



Fig. 58. — The teeth of the sheep {Adapted from Stewart) 



A. At 15 months B. At 2^ years C. At t,\ years D. At 4^ to 5 years 



2 perm-anent incisors 4 permanent incisors 6 permanent incisors Full mouth 



6 deciduous incisors 4 deciduous incisors 2 deciduous incisors 8 permanent incisors 



sufficiently worked over and disintegrated to be acted upon by the 

 gastric juice of the fourth stomach. 



This last compartment is the true stomach corresponding to the single 

 stomach in the horse or in man. It is called the abomasum. Here the 

 gastric juice is formed and true digestion takes place. The food now 

 receives its final disintegration and the nutritive portions are dissolved 

 out, ready to be absorbed by the villi of the intestines. 



The intestines are made up of a long tube which is doubled many 

 times upon itself. The internal coat of these organs is covered with thous- 

 ands of minute absorbent vessels called villi. This coat is a net-work 

 of blood vessels and so-called lacteals resembling the close pile of velvet. 

 The food passes through these organs where the villi pick out the nutri- 

 tive part and pass it into the blood; the blood takes the nutriment to 

 those parts of the body in which it is most needed. 



From the above facts we see that the construction of the digestive 

 tract is not only interesting to the shepherd but instructive also. He 



