viii CONTEXTS 



PAGE 



86. Details of the Adjustment 69 



Ejyperiment 20. Pathway of Adjustment 70 



CHAPTER IV 

 ADJUSTMENT TO LIGHT 



87. Relations of the Plant to Light 71 



88. The Nature of Light Stimuli 72 



89. ileasurement of Light 72 



90. Making a Standard 73 



91. Making Readings 74 



92. Comparison with the Standard 75 



93. Causes of Variation in Light Intensity 75 



94. The Effect of Time 75 



95. The Effect of Altitude 76 



Experiment 21. Measuring Liglit Intensity 77 



96. Reception and Absorption of Light 77 



97. The Amount Absorbed 77 



Experiment 22. Epidermis and Leaf Prints 78 



98. The Production of Chlorophyll 79 



99. The Nature of Chlorophyll 79 



100. The Influence of Darkness 80 



Experiment 23. Influence of Light and Darkness 81 



101. Photosynthesis 81 



102. Absorption and Diffusion of Carbon Dioxide 81 



103. Chemical Changes during Photosynthesis 82 



Experiment 24- Dependence of Photosynthesis ujjon Aeration 



and Light 83 



104. Measurement of Photosynthesis 83 



Experiment 25. Relation of Photosynthesis to Sun and Shade. . 83 



105. Translocation 83 



Experiment 26. Translocation 84 



106. Storage of Food Material 84 



Experiment 27. Storage Tissues 85 



107. Influence of Light upon the Number and Position of Chloroplasts . 85 



Experiment 28. Arrangement of Chloroplasts 87 



108. Movement of Stems and Leaves 87 



109. Phototropism .^ 87 



Experiment 29. Phototropic Movements 89 



110. Nyctotropism 89 



Experiment 30. Nyctotropic Movements 89 



CHAPTER V 

 ADJUSTMENT TO TEMPERATURE 



111. Relations of Plants to Temperature 90 



112. The Measurement of Temperature 91 



