12 CONTENTS 



CHAPTER VI 



PAGE 



The. Rat, a Representative Mammal ____________ 107 



Habitat and Habits, 107; External Structure of the Rat, 108; Skeleton, 

 110; The Muscular System, 115; Digestive System, 121; Glands Asso- 

 ciated With the Digestive System, 124; Circulatory System, 126; Re- 

 spiratory System, 131; The Nervous System, 132; Excretory System, 

 140; Reproductive System, 142. 



CHAPTER VII 



Chordates in General ________________ 146 



Characteristics, 146; Classification, 147; Phylogenetic Advances of 

 Cliordata, 148; Subphylum Hemichorda, 148; Subphylum Urochorda, 

 Molgula, 150 ; Subphylum Cephalochorda, Amphioxus, 152 ; The Verte- 

 brate Animal: Subphylum ^'ertebrata, 157. 



CHAPTER VIII 



Physiology ____________________ 166 



Support and Protection, 166; Movement and Locomotion, 168; Diges- 

 tion, 168; Functions of the Liver, 173; Absorption and Utilization of 

 Food Materials, 173; Vitamins and Their Functions, 174; Respiration, 

 176; Circulation, 178; Nervous Function — Reception and Conduction, 

 180; Functions of the Spinal Cord, 183; Functions of the Divisions 

 of the Brain, 183; Sense Organs and Their Function, 183; Exci'etiou, 

 188; Kidneys, 189; Reproduction, 191. 



CHAPTER IX 



The Endocrine Glands and Their Functions ________ 195 



The Thyroid Gland, 196; The Parathyroid Glands, 198; The Supra- 

 renal Bodies, 199; The Pituitary Gland, 201; The Thymus Gland, 

 203; The Gonads and Sex Hormones, 204; The Pancreas, 205. 



CHAPTER X 



Sexual Reproduction and Development of the Individual _ _ _ _ 209 

 Body Form, 216; Organs and Systems, 217; Nervous System and Sense 

 Organs, 218; Intrauterine Development, 223; Biogenetic Law, or 

 Theory of Recapitulation, 224. 



CHAPTER XI 

 Animal Anomalies _________________ 226 



Causes of Anomalies, 226; Harelip and Cleft Palate, 228; Diaphrag- 

 matic Hernia (Open Diaphragm), 228; Polydactyly (Extra Digits), 

 229; Conjoined Twins, 230; Hermapliroditism, 233; Cardiac Anom- 

 alies, 234; Abnormalities of Brain and Sense Organs, 234. 



