CONTENTS. 



PART II. 



CHAPTER VI. 

 PROTOPLASM AND ITS RELATIONS TO ITS SURROUNDINGS. 



PAGE 



Occurrence of Protoplasm 



Chemical and Physical Properties of Protoplasm ... 



Protoplasmic Movements ' 201 



Relations of Protoplasm to Heat 



ToLight 



To Electricity 



To Mechanical Irritation 



To Gravitation 



To Moisture ^ 



To Various Gases f 



Structure of Protoplasm 2 



Continuity of Protoplasm 2 



Relations of the Cell-wall to Protoplasm 218 



Historical Note regarding Protoplasm 219 



CHAPTER VH. 

 DIFFUSION, OSMOSIS, AND ABSORPTION OF LIQUIDS. 



DIFFUSION AND OSMOSIS 221 



Diffusion of Liquids 221 



Rate of Diffusion 222 



Osmosis 224 



Precipitation-membranes 226 



Traube'sCell 226 



Pfeffer's Apparatus for Osmosis 226 



ABSORPTION OF LIQUIDS THROUGH ROOTS 280 



Root-hairs 231 



Extent of Root-systems 232 



Adhesion of Soil to Roots 233 



Do Roots go in Search of Food ? 286 



CHAPTER Vin. 



SOILS, ASH CONSTITUENTS, AND WATER-CULTURE. 



Amount of Water and of Ash in Plants 236 



SOILS '.'..'... 287 



Formation of Soils .237 



