iv CONTENTS 



PAGB 



II. Movements of Flagella and Cilia 77 



(a) Cells with Flagella 79 



(b) Cells with numerous Cilia 83 



III. The Contractile Vacuoles, or Vesicles, of Unicellular Organisms . 85 



IV. Changes in the Cell during passive movement .... 88 

 Literature 89 



CHAPTEE IV. 



THE VITAL PBOPEKTIES OF THE CELL ....... 91 



Phenomena of Stimulation 91 



I. Thermal Stimuli .94 



II. Light Stimuli 99 



III. Electrical Stimuli . 106 



Phenomena produced by Galvanotropism . . . . . . 108 



IV. Mechanical Stimuli 110 



V. Chemical Stimuli Ill 



(a) Chemical Stimuli which affect the whole body . . . 112 



(b) Chemical Stimuli which come into contact with the Cell- body 



at one spot only 115 



1. Gases 115 



2. Liquids 117 



Literature . 123 



CHAPTER V. 

 THE VITAL PROPERTIES OF THE CELL 126 



Metabolism and Formative Activity 126 



1. Absorption and Excretion ........ 128 



1. The Absorption and Excretion of Gaseous Material . . 128 



2. The Absorption and Excretion of Fluid Substances . . 133 



3. The Absorption of Solid Bodies . . . . .141 

 II. The Assimilative and Formative Activity of the Cell . . .145 



1. The Chemistry of Assimilation ^ 146 



2. The Morphology of Metabolism 154 



(a) Internal Plasmic Products 154 



(b) External Plasmic Products 166 



Literature - .174 



CHAPTER VI. 



THE VITAL PHENOMENA OF THE CELL 177 



Reproduction of the Cell by division 177 



I. History of Cell-formation 177 



II. Nuclear Division . 179 



