TABLE OF CONTENTS XV11 



SECOND PART 



PHYSIOLOGY OF GROWTH AND MOVEMENTS 

 RESULTING FROM IRRITABILITY 



FOURTH SECTION 



MOVEMENTS OP GROWTH 



I. Characteristics of Growing Plant Structures, and Movements of 

 Growth Dependent on Internal Causes 



PAGB 



146. The Extensibility and Elasticity of Growing Plant Structures . . 362 



147. Kelations between Turgidity Growth and Extensibility in Plants . 363 



148. The Contraction of Roots 366 



149. Longitudinal Tension 368 



150. Transverse Tension 370 



151. The Growing Points and Growth in Length 372 



152. Growth in Thickness 375 



153. Apparatus for Measuring Growth Movements 377 



154. The Grand Period of Growth 382 



155. Bate and Energy of Growth 387 



156. Torsions 388 



157. Some Examples of Spontaneous Nutations 389 



II. The Conditions Necessary for Growth, and the Influence of 

 External Conditions on Growth Movement 



158. Growing Plant Structures require Material for Growth . . . 392 



159. The Quantity of Water in Plants, and their Growth . . . .393 



160. Eespiration and Growth 394 



161. The Influence on Growth of Pressure and Tension .... 396 



162. Influence of Temperature on Growth 398 



163. The Annual Period 401 



164. Growth of Plant Structures in Constant Darkness . . . .404 



165. The Causes of Etiolation 408 



166. The Influence of Light on Growth 411 



167. The Influence of Illumination on the Germination of Potato Tubers 414 



