CONTEXTS XV 



CHAPTER XV 

 ALTERNATION AND ZONATION 



PAGE 



310. The Relation between Alternation and Zonation 289 



311. Alternation 289 



312. Causes of Alternation 289 



313. Alternation Due to Ecesis 290 



314. Alternation Due to Competition 291 



315. Kinds of Alternation 291 



316. Normal Alternation of Facies, Consocies, etc 292 



317. Normal Alternation of Species 293 



318. Numerical Alternation 293 



319. Corresponsive Alternation 29-1 



Experiment 71. Alternation of Species 29-1 



320. Zonation 294 



321. Zones Due to Growth 295 



322. Zones Due to Migration and Ecesis 296 



323. Zones Due to Reaction 296 



324. Zones Due to Physical Factors 297 



325. Physiographic Symmetry 298 



326. Symmetry in Vegetation 298 



327. Kinds of Zonation 299 



328. Radial Zonation 299 



329. Bilateral Zonation 300 



330. Vertical Zonation 301 



331. Vegetation Zones 302 



Experiment 72. Zonation of Pond and Meadow Formations 303 



Index 305 



