INDEX. 



251 



o. 



Oceanic climate, peculiarities of, 



123. 



Oxygen of atmosphere, use of, 140. 

 necessity for, in respiration of 

 animals, 141. 



P. 



ParagrSles, 150. 



Parasitic plants, influence of, in 



destruction of forests, 71, 72. 

 Peaty soils, definition of, 51. 

 Pine forests, appearance of scrub 



oak on burning over of, 36, 37. 

 Plant germs, nature's method of 



distributing, 32. 

 wide distribution of, 32 to 



38. 

 wonderful vitality of, 33, 



34, 35, 36. 

 nationality, 26. 

 seeds, wonderful vitality of, 



33, 34, 35, 36. 

 Planting of trees, when advisable, 



157. 



Plants, animals, and minerals, mu- 

 tual interdependence be- 

 tween, 168. 

 conditions necessary for the 



growth of, 20 to 24. 

 decaying, influence of, in for- 

 mation of soil, 50. 

 necessity of oxygen for growth 



of, 23. 



source of germs of, 21. 

 source of seeds of, 21. 

 Polar currents of air, why generally 



drought- producing, 101. 

 land areas, effect of, on earth's 

 climate, 167. 



Prairies, new growth of plants 

 marking wagon-tracks on, 36. 



Precipitation, forms of, 100. 



Pressure of air, influence of, on 

 rapidity of evaporation, 92. 



Prestwich, Joseph, extract from 

 "Geology, Chemical, Physical, 

 and Stratigraphical," 117, 118. 



Products of the forests, 11. 



Protoids, definition of, 29. 



Protoplasm of germ-cell, 20. 



Pouchet, extract from " The Uni- 

 verse," 78, 79, 80. 



Purification of the atmosphere, 

 140 to 145. 



R. 



Railway sleepers, demands on for- 

 ests for, 89. 

 Rain, 100. 



causes of, 100. 



Huxley on the distribution of, 



106. 

 Maury on the distribution of, 



107, 108. 

 Rainfall, distribution of, 102. 



true index of the wealth of a 



country, 94. 



Reclus, Elis6e, extract from 

 "Earth," 67, 68, 69, 

 116, 117. 

 extract from " Ocean," 30, 



31, 48, 49. 



Red River, raft in, 67. 

 Reforestation, 155 to 159. 

 and deforestation, 14. 

 definition of, 155. 

 necessity for government en- 

 couragement of, 156. 

 objects of, 155, 156. 



