INDEX. 



247 



Equatorial land areas, effect of, on 



earth's climate, 166. 

 Erosion, definition of, 54. 



influence of, in the formation 



of soil, 53. 



Evaporation, circumstances influ- 

 encing rapidity of, 90, 91, 92. 

 of moisture, inconstancy of, 



171, 172. 



Excavations, growth of plants on 

 exposure of soil brought up by, 

 35. 



Excessive multiplication of life, 

 how avoided, 169, 170. 



F. 



Feldspathic rocks, clayey soils de- 

 rived from, 51. 



Fernow, B. E., definition of for- 

 estry, 17. 

 Fire, destruction of forests by, 64, 



65, 66. 



Fire-weed, curious conditions re- 

 quired for germination of, 37. 

 Flammarion, Camille, extract from 



" The Atmosphere," 125, 126. 

 Flora, definition of, 26. 



effect of elevation on, 48, 49. 

 effects of the distribution of 

 heat, light, and moisture on, 

 26. 

 influence of temperature on, 



31. 



on mountain slopes, why differ- 

 ent at different altitudes, 26, 

 27. 

 Forest, animate enemies of, 64, 71 



to 76. 



areas, intelligent protection of, 

 13. 



Forest, climate, characteristics of, 



128. 



fires, conditions influencing the 

 rapidity of spread of, 

 65, 66. 



how started, 65. 

 inanimate enemies of, 61 to 67. 

 influence of area on absorption 



of heat, 127. 

 influence of forest area on loss 



of heat, 128. 

 influence of presence of, on 



climate, 127 to 133. 

 lands of the Amazon, 28 

 preserves, 14. 

 Forestry, aims of, 10. 



associations, field for, 10, 13. 

 definition of, 9. 

 Fernow's definition of, 17. 

 laws, necessity for, 10, 13. 

 mistaken ideas concerning, 13. 

 Forests, dependence of, on climatic 



conditions, 62. 

 destruction of, 81 to 86. 

 by beavers, 73. 

 by beetles, 74. 

 by caterpillars, 73, 74. 

 by goats, 73. 

 by grasshoppers, 73, 



74. 



by insects, 73, 74. 

 by man, 75, 76. 

 by mice, 78. 

 by typographer bee- 

 tle, 75. 

 distribution of heat, influence 



of, by destruction of, 84. 

 disturbance of the balance of 

 nature affected by removal 

 of, 172, 173. 



