248 



INDEX. 



Forest, droughts produced by de- 

 struction of, 81. 



encroachments on, necessity 

 for, 11. 



influence of avalanches in de- 

 struction of, 67. 



influence of inundations in 

 destruction of, 66. 



influence of, on humidity of 

 air, 97. 



influence of, on natural drain- 

 age, 113. . 



influence of, on preventing 

 disastrous frosts, 130, 131. 



influence of, on rapidity of 

 evaporation, 97. 



influence of parasitic plants on 

 destruction of, 71, 72. 



influence of rodents on destruc- 

 tion of, 73. 



influence of torrents on de- 

 struction of, 58. 



influence of wind on destruc- 

 tion of, 66. 



inundations produced by de- 

 struction of, 81. 



loss of soil following destruc- 

 tion of, 81. 



malarious diseases produced by 

 destruction of, 82. 



natural drainage disturbed by 

 destruction of, 82. 



necessity for preservation of 

 exact balance of conditions 

 to existence of, 63. 



necessity for removal of, 11. 



of mountain slopes, 46. 



influence of, on 

 rapidity of 

 drainage, 104. 



Forest of tropical regions, 46. 



peculiar distribution of moist- 

 ure causing, 43. 

 products of, 11. 

 protection afforded by, against 



frosts, 129. 



why a regular distribution 

 of moisture is requisite for 

 growth of, 44, 45. 

 why the air of, is cooler and 

 damper in summer than air 

 over open fields in same 

 district, 132. 



Formation of soil, 50 to 57. 

 Freezing and melting of ice, in- 

 fluence of, on disintegration of 

 rocks, 52, 53. 



Gases, absorption of, by soils, 56. 

 Geikie, Archibald, extract from 

 "Text-Book of Geol- 

 ogy," 60, 78, 88, 133. 

 Germ, necessity for existence of, for 



plant life, 23. 



Germ-cell, protoplasm of, 20. 

 Germs of plants, source of, 21. 



wonderful vitality of, 



21, 33, 34, 35, 36. 

 of seeds, wonderful vitality of, 



33, 34, 35, 36. 

 Glaciers, definition of, 54 



influence of, in formation of 



soil, 54, 59. 

 Goats, destruction of the forests by, 



73. 

 Grasshoppers, destruction of forests 



by, 73, 74. 

 Gravelly soils, definition of, 50. 



