x CONTENTS 



PAGE 



air in contact with the membrane — Respiratory muscles 

 — Inspiration — Expiration — Effect of the elasticity of the 

 lungs on the diaphragm — Phraseology — Hygiene of res- 

 piration — Summary 23 



CHAPTER III 



ASSIMILATION 



Steps in the process — Nature of the process — In one-celled 

 animals — In many-celled animals — The complete digestive 

 tract — Variations in development — Diet of animals — The 

 five food substances — Water — Salts — Carbohydrates — Hy- 

 dro-carbons — Proteids — Necessary proportions of food sub- 

 stances — Nutriment in foodstuffs — Digestion — Enzymes 

 — Enzymes in the digestive juices — Reversible action of 

 enzymes — Enzymes in the tissues — Passage of food 

 through the canal — Absorption in the intestine — Excre- 

 tory organs — The kidneys — Urea — The sweat glands — 

 Hygiene of digestion — Summary 45 



CHAPTER IV 



CIRCULATION 



Necessity for circulation — The system — In lower animals — 

 In higher animals — Mechanical factors which control the 

 circulation, 1) The heart, 2) The valves, 3) The closed 

 system, 4) Elasticity, 5) Tone — Composition of the 

 blood — The red corpuscles — Relation between ogyxen and 

 hemoglobin — Oxygen can not establish an equilibrium — 

 Origin and fate of the corpuscles — The white corpus- 

 cles — Coagulation — The serum — The lymph — The lym- 

 phatics — Vaso-motor nerves — Relation to the body tem- 

 perature — Interference with the vaso-motor mechanism 

 — Effect of alcohol on body temperature — Adaptation of 

 the circulation to bodily need — Summary 67 



CHAPTER V 



REPRODUCTION 



Origin of living matter unexplained — Reproduction — In one- 

 celled animals — In many-celled animals — Restricted to 



