CONTENTS 



LECTURE V 



The R6le of Electrolytes in the Formation and Preservation of 

 Living Matter 



PAGE 



1. On the Specific Difference between the Nutritive Solutions for Plants and Animals 



— Protective Solutions and Nutrient Solutions 71, 



2. Concerning a Theory of Irritability and the Role of Na, K, and Ca for Animal Life 



— Rhythmical Contractions in Skeletal Muscle, in Medusae, and the Ven- 

 tricle of the Heart — Contact Irritability in Muscle — Analogies Juj the R61e 

 of Salts in Coagulation of Milk — Significance for the Understanding of 

 Functional Nervous Diseases — The Action of Purgatives .... 78 



3. The Reaction of Living Matter and the R61e of Bicarbonates in the Preservation 



of Life 95 



4. Electrical Stimulation 98 



LECTURE VI 

 The Effects of Heat and Radiant Energy upon Living Matter 



1. Effects of Heat — Upper Temperature Limit of Life — Influence of Reaction- 



velocity upon Biological Processes — Lower Temperature Limit" — Other 

 Biological Effects of Heat 106 



2. General Effects of Radiant Energy upon Living Matter — Chemical Action of Light 



upon Organisms . . . .112 



LECTURE VII 

 Heliotropism 



1. The Heliotropism of Sessile Organisms . . . 117 



2. Heliotropism of Free-moving Animals 124 



3. The Control of the Precision and Sense of Heliotropic Reactions in Animals . . 130 



4. The Reaction of Animals to Sudden Changes in the Intensity of Light . . -135 



LECTURE VIII 

 Further Facts concerning Tropisms and Related Phenomena 



1. General Theory of Tropisms 138 



2. Galvanotropism 141 



3. Geotropism .... I4y 



4. Chemotropism and Related Phenomena Ijj 



5. Stereotropism ijt 



6. Concluding Remarks concerning Tropismlike Reactions 158 



LECTURE IX 

 Fertilization 



1. The Specific Character of the Fertilizing Power of the Spermatozo6n Hybrid 



Fertilization jgl 



2. Artificial Parthenogenesis and the Theory of Fertilization i5< 



