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CHAPTER XXIX. 

 FEEDS AND FEEDING. 



THE nourishment and development of animals is more 

 complicated than the growth of plants. Their growth is 

 from the use of substances ready formed in plants, or which 

 have been derived from them. These are transformed into 

 flesh and bone. 



Composition of Animals. The animal body is composed of 

 substances derived directly or indirectly from plants. It may 

 be divided into two classes of products, water and dry matter. 



Water ordinarily is more than one-half of the total weight 

 of the live animal and is necessary for the proper nourishment 

 of the body. Pure fresh water should be supplied freely to 

 all animals. 



The dry or solid matter of an animal's body is made up 

 of several different substances, called tissues, as fat, muscle, 

 bone and others. The chief substances which enter into 

 these are fat. protein, horny matter and mineral matter. 



EXERCISE. Water in Flesh. Heat a small piece of fresh 

 lean beef or other meat in a long glass test tube. Notice 

 the water which rises and collects on the cooler parts of the 

 vessel. If delicate scales or balances are in the school, the 

 meat may be weighed before and after heating. Thus the 

 weight of water driven off may be determined. 



EXERCISE. To Get Dry Matter. Place a few small pieces 

 of air-dry wood of any kind in a glass test-tube or bottle 

 over a flame or on a hot stove. The moisture will escape 

 from the wood and condense on the cooler parts of the glass 

 above the wood where it can be seen. After a time only the 

 dry matter will remain in the bottom of the glass. If the 

 wood be weighed before and after drying, the per cent of 

 dry matter may be determined. 

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