XIV 



CONTENTS 



a species 



§ 154. Annuals .... 



§ 155. Biennials .... 



§ 156. Perennials .... 



§ 157. Changes in the length of life of 



§ 158. Buds 



§ 159. Naked buds 



§ 160. Scaly buds 



§ 161. Buds of the apple 



§ 162. Buds of elder, maple, or elm 



§ 163. Sleeping buds . 



§ 164. The awakening of sleeping buds 



§ 165. Winter buds of aquatic plants 



§ 166. Behavior of the hibernacula 



§ 167. Bulbs 



§168. Corms .... 



§ 169. Forcing or inducing an earlier growth 



§ 170. Some protective devices of the shoot 



§ 171. Branches used as leaves 



§ 172. The part of stems in the struggle for existence 



§ 173. Weeds 



§ 174. Climbing plants .... 



§ 175. The irritability or sensitiveness of stems 



§ 176. Sensitiveness to gravity 



§ 177. Stems are found among the higher plants only 



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Vn. The Wat in which New Plants Arise 



§ 178. Distribution of the individuals of a species . . . 130 



§ 179. Methods of reproduction 131 



§ 180. Reproduction by cuttings 132 



§ 181. The stem may reproduce the entire plant . . . 132 

 § 182. The root may reproduce the entire plant .... 132 

 § 183. Structures used by plants as means of vegetative repro- 

 duction 133 



§ 184. Tubers 133 



§ 185. Bulbils and bulblets 134 



