LIST OF ILLUSTRATIONS. 



XIII 



Plate 55 — Continued. 



B. Stump staae exposed by digging peat; a 

 colony of the subsere in midground, 

 CaUuna at edge, Klosterlund Moor, 



Jylland, Denmark 294 



Plate 56. 



Lateral planation of the Saskatchewan 

 River, Medicine Hat, Canada: 



A. Filling and colonization on the left 



bank 310 



B. Undercutting and destruction of Arte- 



misile canae on the right bank . . . 310 

 Plate 57. Humphreys's chart of sun-spot 



numbers and volcanic eruptions. ... 310 

 Plate 58. 



A. Red rocks and gypsum ridge, indicating 



an arid climate in the Mesophytic 

 era. Garden of the Gods, Manitou, 

 Colorado 314 



B. Travertine cliff at the margin of an old 



lake basin, Hazen, Nevada 314 



PAQE. 



Plate 59. 



A. Culture relicts indicating a moister cli- 



mate, Spruce Tree House ruins, 

 Mesa Verde National Park, Colo- 

 rado 324 



B. Culture relicts indicating a drier climate, 



ruins of Copan, Honduras 324 



Plate 60. 



A. Sequoia sempenirens, Muir Woods, 



Mount Tamalpais, California 324 



B. Sequoia gigantea, Mariposa Grove, Wa- 



wona, California 324 



Plate 61. 



A. Section of the heal edge of a double soar, 



furnishing the dates of two successive 

 fires. Long's Peak, Colorado 436 



B. Permanent quadrat in gravel-slide colo- 



nized by Scutellaria and Wagnera, 

 Cross Ruxton, Minnehaha, Colo- 

 rado 436 



TEXT-FIGURES. 



10. 



11. 



12. 



13. 



14. 

 15. 

 16. 



17. 

 18. 



19. 

 20. 



21. 



22. 

 23. 

 24. 

 25. 

 26. 



27. 



PAGE. 



Section of Vidnesdam moor in Denmark . . 14 

 Section of Lillemose moor in Denmark ... 15 

 Schematic representation of development 



of the hydrosere 112 



Section of salt and diked marshes of Bay 



of Fundy 190 



Halosere at Cold Spring Harbor, New 



York 202 



Diagram of development of climax forest 



on Isle Royale 209 



Psammosere in Central Illinois 215 



Diagram of development of maple-beech 

 climax about Lake Michigan, show- 

 ing course of xerosere 218 



Diagram of development of maple-beech 



climax, showing course of hydrosere . 221 

 Hydrosere in the island of Oland, Sweden . 243 



Lithosere on lava in Iceland 248 



Moor, limestone, and dune seres in Somer- 

 set, England 251 



SeraJ relations of moorland, Caithness, 



Scotland 253 



Serai relations of woodland in England . . 255 

 Serai sequences in the Pennines, England . 255 

 Serai communities on chalk, southern 



England 255 



Hydrosere in Norfolk, England 256 



Generalized section of Lonsdale estuarine 



moors 256 



Section of the Lonsdale lacustrine moors . . 257 

 Diagram of alpine communities, Ben 



Lawers, Scotland 257 



Relations of communities on siliceous and 

 limestone soils. Peak District, Eng- 

 land 261 



Prisere and subsere in the Philippines. . . 278 



Diagram of deformation sequences 299 



Origin of unconformity 306 



Development of a base-level of erosion . . 308 

 Schuchert's chart of geological climates 



and deformations 321 



An anti-pleion, or "lean year," as shown 



by the corn crop of the United States. 331 



PAGE. 



28. Apleion, or"fatyear" 331 



29. Monthly departures of temperatures in 



south equatorial regions 332 



30. Correlation of tree-growth with 11-year 



and 21-year cycles 335 



31. Major and minor sun-spot cycles 337 



32. 150-year cycle 337 



33. 600-year curve of tree-growth 337 



34. Major sun-spot cycles as shown by curve 



of growth of Sequoia trees 338 



35. Costase of forest climaxes buried by vol- 



canic ejecta 367 



36. Ice-mass and the cliseral zones in front 



of it during a glacial epoch 374 



37. Diagram showing the successive positions 



of the zones of the clisere during a, 



glaoial-interglacial cycle 376 



38-39. Sections of peat stase with stump 



layers, Sweden 381 



40. Adseres of the hydrosere in southern 



Sweden 385 



41. Succession of peat strata in northeast 



Highlands of Scotland 391 



42. Layers of costase in Scottish peat-bogs . . 392 



43. Section showing position and relations of 



Permian glacial beds in AustraUa . . . 407 



44. Relative distribution and probable phy- 



logeny of the great groups of plants 

 during the vegetation eras 418 



45. Section of the Coal Measures in Ohio. . . . 421 



46. Quadrat showing reproduction in a com- 



plete burn 427 



47. Quadrat showing seedlings of lodgepole 



pine in a Vacdnium cover 428 



48. Belt transect through forest of lodgepole 



pine, bare burn, and half burn 431 



49. Bisect of sand-hills mixed association in 



eastern Colorado 433 



50. Bisect of the BuXbilis-Boutelowir-poion in 



eastern Colorado 433 



51. Transect of a migration arc 434 



