X CONTENTS 



acid — 82. Toxic action of potassium hydrate — 83. Substitution poisons — 84. Toxic 

 action of phenol — 85. Toxic action of phloroglucin — 86. Toxic action of formalde- 

 hyde — 87. Poisonous proteinaceous substances — 88. Toxic action of alkaloids — 

 8g. Self-poisoning — go. Acclimatization to chemical action — 91. Changes which 

 ensue in protoplasm during acclimatization — g2. Chemotaxis — g3. Relations of 

 the organism to trophic and other compounds — g4. Chemotaxis of antherozoids of 

 ferns — g5. Chemotactic movements of bacteria- — g6. Chemotropic movements of 

 pollen tubes — 97. Chemotropic stimulation of stigmas for pollen tubes — g8. Chemo- 

 tropism of Mucor, and other moulds to sugar — gg. Influence of chemical stimulation 

 upon developmental processes. 



IV. Relations of Plants to Water 65-70. 



100. Water as a factor in living matter — 101. Effect of desiccation upon move- 

 ment of protoplasm — 102. Resistance of seeds to desiccation — 103. Hydrotropic 

 reaciions — 104. Prohydrotropism of roots — 105. Reactions of plasmodia to water : 

 hydrotropism — 106. Rheotropic reactions of plasmodia — 107. Influence of water 

 and water vapor on form — 108. Form and structure of organs in water and watery 

 vapor. 



V. Relation of Plants to Gravitation 71-88. 



log. Nature of the relation of gravitation to plants — no. Nature of the stimu- 

 lating influence of the force of gravity — in. Latent period, reaction time, presen- 

 tation period — 112. Determination of reaction time — 113. Determination of pre- 

 sentation time — 114. Effect of slow revolution of clinostat — 115. Influence of 

 external conditions upon geotropic reactions — 116. Delayed reactions — 117. After 

 effects of stimulation — 118. Sensory zone of roots — ng. Alternating and intermit- 

 tent stimulation — 120. Rhythmic effects of alternating stimulation — 121. Chemical 

 changes in a geotropically stimulated root — 122. Transmission of geotropic impulses 

 — 123. Mechanism of curvature of roots — 124. Diageotropism of secondary roots — 

 125. Sensory zone of shoots — 126. Region and form of curvature — 127. Mechanism 

 of curvature of grass stems — 128. The geotropic relations of dorsiventral organs — 

 129. Rotation and curvature of petioles of dorsiventral leaves in response to geotropic 

 stimuli — 130. Geotropic curvatures in organs in which growth in length has ceased 

 — 131. Diageotropism of flowers of Narcissus — 132. Lateral geotropism of twining 

 plants — 133. Revolving movements of tips of twining plants — 134. Behavior of 

 twining plants when freed from the influence of gravity — 135. Alterations in geo- 

 tropic properties — 136. Recovery from a position assumed geotropically — 137. 

 Recovery of position of roots — 138. Formative influence of gravity. 



VT. Relations of Plants to Temperature 89-100. 



I3g. General relations of temperature to protoplasm — 140. Tonicity to temper- 

 ature — 141. Adjustment to changes in temperature — 142. Stimulating influence 

 of changes in temperature — 143. Resistance and acclimatization of seeds to heat — 

 144. Relation of water content to endurance of high temperatures — 145. Influence 

 of temperature upon movement of protoplasm — 146. Relation of low temperatures to 

 resting seeds, bulbs and tubers — 147. Freezing of unicellular organisms — 148. 

 Freezing of tissues — 149. General observations on freezing — 150. Formative effect ; 

 thermal constants — 151. Thermotropism — 152. Thermotropism of leaves — 153. 

 Thermotropic reactions of shoots — 154. Influence of temperature upon the opening 

 or closing of flowers — 155. Thermotropic reactions of tendrils, Dionaea, &c. 



VII. Relation of Plants to Electricity and other forms of Energy. 



101-109. 

 156. Nature of influence of electricity upon plants — 157. Measurement of differ- 

 ences in electric potential — 158. Differences in potential due to metabolism — isg. 



