xiv 
CONTENTS 
262.. Mobility 
, 263.. Organs for dissemination 
. 264.. Contrivances for dissemination 
265. Position of disseminules 
266. Seed production . 
267.. Agents of migration . 
268. The direction of migration 
Ecesis 
269. Concept 
270. Germination of the one 
271. Adjustment to the habitat . 
Barriers 
272. Concept . 
273. Physical barriers 
-274. Biological barriers 
275. Influence of barriers . 
Endemism 
276. Concept 
277. Causes 
278. Significance 
Polyphylesis and Polywenesis 
279. Concept — : ; 
280. Proofs of polypeniesis: * 
281. Origin by polyphylesis 
Kinds of Invasion 
282. Continuous and intermittent invasion 
283. Complete and partial invasion 
284. Permanent and temporary invasion . 
Manner of Invasion 
285. Entrance into the habitat 
286. Influence of levels 
Investigation of Invasion 
287. 
Succession 
288. Concept 
289. Kinds of succession 
Primary Successions 
291. Succession through elevation 
292. Succession through volcanic action 
293. Weathering 
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