CONTENTS 13 



PAGE 

 494; Muscular System, 496; The Nervous System and Sense Organs, 

 497; The Bullfrog, 497; Habitat, 497; External Structure, 497; 

 Digestive System and Digestion, 499; Circulatory System, 502; 

 Respiratory Organs and Eespiration, 514; Excretory System and Ex- 

 cretion, 515; Skeletal System, 517; Muscular System, 523; Nervous 

 System, 525; The Sense Organs, 528; Reproductive Organs, 531; 

 Embryology, 532; The Toad, 538; Habitat, 538; External Features, 

 539; Internal Structure, 541; Respiratory and Digestive Organs, 

 541 ; Urinogenital Organs, 541 ; Blood Vascular System, 542 ; Skeleton 

 and Muscles, 543 ; Nervous System and Sense Organs, 543 ; Em- 

 bryology, 544. 



CHAPTER XXIX 



Reptilia (By Leo T. Murray and James E. Blaylock) ______ 545 



Fossil Reptiles, 546; Classification of Living Reptiles, 547; Class — 

 Reptilia, 547; Order Testudinata (Chelonia), 548; Order Squamata, 

 551; Order Rhincocephalia, 560; Order Crocodilia, 560; The Horned 

 Lizard, 561; Habits and Behavior, 561; External Structure, 562; 

 Digestive System, 563; Respiratory System, 566; The Circulatory Sys- 

 tem, 566; The Urinogenital System, 571; The Nervous System, 573; 

 The Skeletal System, 574; Muscular System, 576; The Turtle, 577; 

 Habits and Behavior, 577; External Structure, 578; Digestive System, 

 578; Respiratory System, 579; Circulatory System, 580; Urinogenital 

 System, 581; The Nervous System, 581; The Skeleton, 581; The 

 Muscular System, 581. 



CHAPTER XXX 



AVES _____________________ 582 



Classification, 584; Economic Relations, 596; Domestic Chicken, 598; 

 Habits and Behavior, 598; External Structure, 599; Digestive Sys- 

 tem, 601; Respiratory System, 603; Circulatory System, 604; Excretory 

 System, 606; Nervous System, 607; Skeletal System, 609; Muscular 

 System, 612; Reproduction and Life History, 613. 



CHAPTER XXXI 



Mammalia _________-__-__----- 616 



Classification, 616; Economic Relations, 637; The Cat, A Representa- 

 tive Mammal, 639; External Structure, 639; Skeleton, 641; Muscu- 

 lar System, 644; The Digestive System, 646; Circulatory System 

 648; Respiratory System, 649; Nervous System, 650; Excretory 

 System, 650; Reproduction and Life History, 652. 



CHAPTER XXXII 



Animal Anomalies _________________ 654 



Harelip and Cleft Palate, 656; Diaphragmatic Hernia (Open Dia- 

 phragm), 657; Polydactylism (Extra Digits), 659; Conjoined Twins, 

 659; Hermaphroditism, 663; Cardiac Anomalies, 664; Abnormalities 

 of Brain and Sense Organs, 664. 



