xiv 



CONTENTS 



PAGE 



II. Movementsof 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. 



IHB VITAL PBOPERTIES or THE CELL 91 



Phenomena of Stimulation . . . 91 



I. Thermal Stimuli 94 



H. 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 

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



at one spot only 115 



1. Gases 115 



2. Liquids 117 



Literature 123 



CHAPTEK V. 



THE VITAL PROPERTIES OP THE CELL 126 



Metabolism and Formative Activity 126 



I. 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 



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



1. The Chemistry of Assimilation 145 



2. The Morphology of Metabolism . . . . .154 



(a) Internal Plasmic Products 154 



(b) External Plasmic Products 166 



Literature 174 



CHAPTEE VI. 



THB VITAL PHENOMENA OP THE CELL ...... 177 



Eeproduction of the Cell by division 177 



I. History of Cell-formation ..... 177 



II. Nuclear Division 179 



