CHAPTER XXIV 



NEEDS OF THE ANIMAL: USE OF FOOD BY MAN AND 

 OTHER ANIMALS 



To TEACHERS. Certain fundamental principles of animal 

 physiology are, as a rule, best approached through the study 

 of the human body, as treated in Chapters 24, 25, and 26. 

 If the pupil already has a sound knowledge of these matters, 

 they may be omitted, or only such parts taken up as apply 

 to the farm animals. The directions for the care of the health 

 may be left to the discretion of the teacher. 



So far our study has been mostly about plants. We 

 will now try to learn something about how animals 

 (including man) digest their food, breathe, and move 

 about, as well as how the chief organs of their bodies 

 act and how they should be cared for. We shall then 

 study the different kin'ds of farm animals. 



What do animals need? When we think over our 

 own needs, we see that they are the same as those of 

 the plant : air, water, food, light, and warmth. These 

 are the needs of all animals. Each need brings a 

 problem to solve. The animal that learns how to get 

 these things in the best and easiest way will get ahead 

 of the rest in the struggle for life that always goes on. 



How long can animals live without supplying these 



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