Viii CONTENTS 



4. Respiration of Tetrapods 42 



(a) Ventilation in the Frog 44 



(b) Respiration of Reptiles 47 



(c) Birds 50 



(d) Mammals 56 



(e) Diving in Tetrapods 60 



5. The Metabolic Activity 



OF Vertebrates 67 



(a) Body size and metabolism 67 



(b) Metabolic rate and temperature 70 



(i) Poikilotherms 71 



(ii) Homoiotherms 73 



(iii) Hibernation 75 



6. Control of Respiration 



AND Body Temperature 79 



(a) Respiration 79 



(b) Chemical regulation of respiration 83 



(c) Temperature control 86 



(i) Heat production and conservation 86 



(ii) Heat loss 89 



(iii) Nervous mechanisms 90 



7. Transport of the Respiratory Gases 94 



(a) The transport of oxygen 94 



(b) The transport of carbon dioxide 99 



8. The Heart and Circulatory System 



IN Relation to Aquatic and 



Aerial Respiration 102 



(a) The heart and aortic arches of fishes 103 



(b) Circulation in bony fishes v^ith air-breathing 



organs 106 



(c) The heart and aortic arches of Dipnoi 107 



(d) The heart and aortic arches of Amphibia 108 



