xvi CONTENTS 



Page 



Excretory system — Reproductive system — Muscular system — Nervous sys- 

 tem — Convergence and divergence. 



CHAPTER LXIII 



Development of the Organism 447 



Germ cells — Origin of germ cells — Maturation of the germ cells — Egg — 

 Fertilization — Cleavage — Blastula — Gastrulation — Mesoderm formation — 

 Tissue formation and organogeny — Postembryonic development — Potential 

 immortality of germ cells. 



CHAPTER LXIV 



Energy Changes in Organisms 452 



Chemical changes in the body — Organism compared to a fire — Organism 

 compared to an engine — Organism more than a machine — Individuality — 

 Rhythmicity — Uses of foods — Planes of metabolism — Body heat — Heat 

 regulation — Warm-blooded and cold-blooded animals — Temperature of the 

 human body. 



CHAPTER LXV 



Functions of Animal Organisms 458 



Chemical cycles — Water — Digestion and absorption — Circulation — Respira- 

 tion — Secretion — Internal secretions — Excretion and eUmination — Motor 

 functions — Nervous activities. 



CHAPTER LXVI 



Behavior of Animal Organisms 469 



Memory — Types of animal behavior — Direct response — Simple reflexes — 

 Instincts — Habits — Learning — Intelhgence — Reasoning — Combinations of 

 modes of behavior — Behavior of lower and of higher animals — Mind and 

 consciousness. 



CHAPTER LXVII 



Animal Organisms in Relation to Their Environment 477 



Facts of ecology — Relations of animals to plants — Physiological life histories 

 — Habitat — Ecological factors — Reactions of the animal — Communities — 

 Succession — Rhythms — Marine faunas — Fresh-water animals — Terrestrial 

 faunas — Mimicry and protective resemblance. 



CHAPTER LXVIII 



Animal Organisms in Health and Disease 487 



Definitions — Health in a protozoan — Comparison of protozoan and metazoan 

 cells— Conditions of health— Causes of disease— Effect of individuality— 

 Self-regulatory tendency in the bodj^ — Toxins and antitoxins — How the 

 body fights disease — Immunity — Anaphylaxis and allergy — Maintenance of 

 health in human beings. 



CHAPTER LXIX 



Relations between Animal Organisms 493 



Solitary life — Associations of animals of the same species — Mating — 

 Families — Colonies — Societies — Associations of animals of different species — 

 Gregariousness — Epizoic associations — Commensalism — Mutualism — Sym- 

 biosis — Parasitism — Predatism. 



