CONTENTS. ix. 



CHAPTER X. 

 The Chemical Constituents op Plants. 



rAGE. 



g 1. The Water in tlie Plant — Amount of Water in Plants — Water 

 in the Protoplasm — Water in the Cell Walla — Water in the 

 Intercellular Spaces — Equilibriuui of the Water in the Plant — 

 Disturbance of Equilibrium — Evaporation of Water — Amount 

 of Evaporation — The Movement of the Water in the Plant 

 — § 3. As to Solutions — § 3. Plant Food — The Most Important 

 Elements — The Compounds Used — How the Food is Obtained 

 — How Transported in the Plant 166. 



CHAPTER XI. 



The Chbmicai; Processes in the Plant. 



§ 1. Assimilation — § 3. Metastasis — Its General Nature — Trans- 

 formation of Starch — Nutrition of Protoplasm — The Storing of 

 Reserve Material — The Use of Reserve Material — The Nutri- 

 tion of Parasites and Saprophytes — The Formation of Alkaloids 

 — Results of Metastasis 17& 



CHAPTER XII. 



The Relations op Plants to External Agents. 



g 1. Temperature — General Relations — Absorption of Water as Af- 

 fected by Temperature — Evaporation— Assimilation— Metasta- 

 sis — Death from too High a Temperature— Death from too 

 Low a Temperature— § 3. Light: General Relations of Light 

 to Assimilation, Light, and Metastasis — g 3. Heliotropism — 

 S 4. Geotropism — § 5. Certain Movements of Plants : General 

 Statement, Spontaneous Movements, Movements Dependent 

 upon External Stimuli, Movements of Nutation, Movements 

 of Torsion , 184 



PART II. SPECIAL AKATOMY AXD PHYSIOLOGY. 



CHAPTER XIH. 

 Classification. 



Principles of a Natural Classification- Critical— A Comparison of 



several Systems 203 



