Xi\' CONTENTS 



Chapter 25 



A HISTORY OF VERTEBRATES: AMPHIBIANS AND 



REPTILES 446 



202. The Transition from Water to Land 446 



203. Evolution and Characteristics of Amphibians . . 447 



204. Amphibian Adaptations 448 



205. C^haracteristics of Reptiles 453 



206. Evokition and Adaptations of Reptiles 456 



Chapter 24 



A HISTORY OF \ ERTEBRATES: BIRDS AND MAMMALS ... 468 



207. Principles of Flight 468 



208. Structure of Birds 471 



209. The Origin and Evolution of Birds 478 



210. The Bird Way of Life 481 



211. Characteristics of Mammals 486 



212. Primitive Mammals 491 



213. Adapti\e Radiation of Eutherians 492 



Chapter 25 



PROTECTION, SUPPORT AND MOVEMENT 502 



214. The Integument 502 



215. The Skeleton 506 



216. Muscles 512 



Chapter 26 



DIGESTION AND RESPIRATION 515 



217. The xMouth 515 



218. The Pharynx and Esophagus 518 



219. The Stomach 519 



220. The Liver and Pancreas 520 



221. The Intestine 521 



222. The Control of Digestive Secretions 524 



223. Use of Absorbed Materials 525 



224. Respiratory Membranes 528 



225. The Respiratory System of Fishes 529 



226. The Respiratory System of Terrestrial 



Vertebrates 531 



227. The Mechanics and Control of Breathing 533 



