TABLE OF CONTENTS Xlll 



CHAPTER XXX 



PAGE 



SOME COMMON FISHES OF NORTH AMERICA . . . 278 



ELASMOBRANCHII (278). TELEOSTOMI (279). DIPNOI 

 (284). 



CHAPTER XXXI 

 THE RELATIONS OF FISH TO MAN .... .285 



Game fishes (285). Food fishes (288). The canning of 

 salmon (292). The value of the fishing industry (293). The 

 artificial propagation of fishes (294) . The artificial propaga- 

 tion of the lake trout (295). Work of the United States 

 Bureau of Fisheries (296). 



CHAPTER XXXII 

 THE AMPHIBIA 299 



Tailed amphibians (299). Tailless amphibians (301). 

 Regeneration (304). Hibernation (305). Poisonous am- 

 phibia (305). The common toad (305). The economic 

 importance of amphibia (307). 



CHAPTER XXXIII 



THE REPTILIA 39 



TURTLES (310). Habitat (314). Fresh-water turtles (314). 

 Terrestrial turtles (316). Sea turtles (317). LIZARDS (319). 

 SNAKES (322). Harmless snakes (324). Constrictors (326) . 

 Poisonous snakes (326). CROCODILES AND ALLIGATORS 

 (331). The economic importance of reptiles (332). 



CHAPTER XXXIV 

 THE STRUCTURE AND ACTIVITIES OF BIRDS . . . 335 



The body built for flight (335). The wings as organs of 

 flight (335). Steering the body during flight (339). How 

 the feet are used (339). How the beak is used (343)- Birds 

 are warm-blooded animals (345). Feathers (346). Molting 

 (347). Internal organs (348). Bird songs and call notes 

 (349). Bird migration (350), Mating (354). Nest building 



