XIV CONTENTS 



PAGE 



272. Vegetation Pressure 257 



273. The Results of Competition 258 



274. The Study of Competition 259 



275. Competition Cultures 259 



276. Competition Quadrats 261 



Experiment 66. Competition 261 



277. Ecesis 261 



278. The Factors in Ecesis 262 



279. Germination of the Seed 263 



280. The Effect of Habitat 264 



281. Adjustment to the Habitat 265 



Experiment 67. Influence of Habitat form upon Ecesis 265 



282. Barriers 265 



283. Physical and Biological Barriers 266 



284. Influence of Barriers 266 



285. Distance 267 



286. Endemism 268 



Experiment 68. Barriers and Endemism 269 



CHAPTER XIV 



INVASION AND SUCCESSION 



287. Invasion 270 



288. The Manner of Invasion 270 



289. Invasion at Different Levels 272 



290. Kinds of Invasion 272 



291. Indigenous and Derived Species 273 



Experiment 69. Invasion 273 



292. Succession 273 



293. Ivinds of Succession 274 



294. Primary Successions 275 



295. Succession in Colluvial Soils 276 



296. Succession in Alluvial Soils 277 



297. Succession in ^oUan Soils 278 



298. Secondary Successions 278 



299. Sviccession in Eroded Soils 279 



300. Succession in Flooded Soils 280 



301. Successions Due to Man 280 



302. Successions in Burned Areas 28 1 



303. Succession in Lumbered Areas 282 



304. Succession by Cultivation 282 



305. Reactions of Plants upon the Habitat 282 



306. The Laws of Succession 284 



307. The Study of Successions 286 



308. Method of Alternating Areas 286 



309. The Relict Method 287 



Experiment 70. The Study of a Secondary Succession 288 



