vi PLAN OF THE BOOK 



" story plan" has been adopted so far as it is possible 

 in the treatment of physiology. 



The cell is taught as the unit of structure and func 

 tion from the very first. The pupil learns something 

 of the life history of the amoeba in the first chapter. 

 He studies the medium in which the amoeba lives, and 

 learns how the amoeba gets its food, and how it elimi- 

 nates its waste products. Then he learns that each cell 

 of the human body is a living, acting unit that resem- 

 bles the amoeba in its life history. Then follows a 

 study of the medium in which the cells of the human 

 body live, and from which they obtain their food, and 

 to which they give off their wastes. This naturally 

 leads to a consideration of the whole subject of food 

 solids, liquids, and gases. 



After learning what the different foods are, where they 

 come from, and the amount required, he must see how 

 each gets into the blood and becomes part of the blood. 

 In the chapter on Respiration he learns how oxygen 

 the simplest food gets into the blood. Then follows 

 a chapter on Digestion and one on Absorption, to see 

 how the solid and liquid foods are prepared for the 

 blood and how they enter the blood. After the three 

 kinds of food have been traced into the blood he studies 

 Circulation, to learn how the foods are carried to the 

 various cells in all parts of the body. Next he learns 

 what becomes of the foods in the cells, what uses they 

 serve, and what waste products they form. Then these 

 waste materials are traced to the organs of excretion, 

 and he learns how they are taken out of the blood and 



