CONTENTS ix 



PAGE 



CHAPTER XXVII. FISHES 239 



Structure, external and internal. Life History. Adaptations. 



Economic value. 

 CHAPTER XXVIII. THE FROG AND ITS RELATIVES. . .' 252 



Characteristics of the amphibia. Structure of frog. Adaptations. 

 CHAPTER XXIX. THE AMPHIBIA; LIFE HISTORY AND HABITS 267 



Metamorphosis of frog. Toad, Salamander and Frog compared. 



Economic importance. 

 CHAPTER XXX. REPTILES 273 



Representatives. Characteristics. Adaptations. False ideas. 



Poisonous snakes. Treatment. 

 CHAPTER XXXI. BIRD STRUCTURE AND ADAPTATIONS 281 



Characteristics. Adaptations for flight. Adaptations for active 



life. Adaptations of beaks and feet. 

 CHAPTER XXXII. BIRD HABITS 294 



Food. Nesting. Eggs. Migration. Economic importance. 

 CHAPTER XXXIII. MAMMALS 310 



Characteristics. Adaptations of limbs, teeth, and body coverings. 



Special adaptations of rodents, ungulates, carnivora and primates. 



Man's place in the group. 

 CHAPTER XXXIV. THE DEVELOPMENT OF MAN 321 . 



Relation to other animals. Idea of evolution. Evidences of evo- 

 lution. 

 CHAPTER XXXV. THE METHOD OF EVOLUTION 326 



Antiquity of the idea. Lamarck's theory. Darwin and Natural 



Selection. Summary of the theory; its conclusions. 



CHAPTER XXXVI. THE DEVELOPMENT OF CIVILIZED MAN 333 



Ancient records. Primitive man. Stages in development. Imple- 

 ments used. Results of higher mentality. Present races. 



CHAPTER XXXVII. FOOD 342 



Necessity. Definition. Functions of various food stuffs. Measure- 

 ment of values. Proportions. Balanced ration. Digestibility. 

 Cost. Cooking. Lipoid. Vitamines. 



CHAPTER XXXVIII. NUTRITION 363 



Digestive changes. Digestive organs. Mouth. Teeth. Stomach. 

 Intestine. Glands. Absorption. Assimilation. 



CHAPTER XXXIX. RESPIRATION 382 



Development of organs, in lower forms. Structure and adaptation 

 of nose, trachea, lungs, diaphragm. Changes in air and blood. Venti- 

 lation. 



CHAPTER XL. CIRCULATION 392 



Function. Blood, its composition and use. Heart. Arteries, Veins, 

 Capillaries. Lymph circulation. 



