Contents 



CHAPTER XVI 



SUNSHINE, RAIN, AND WIND 



Curious habitats of plants— The Darnel Fungus— Oak leaves and 

 climate — Shapes of leaves and harmony — Waterfall plants — 

 Statistical researches — Changes during growth of a wood — Lime- 

 stone plants— Sunshine effects — Bracken in various situations — The 

 patanas of Ceylon — Railway lines in Sweden — Reddening of plants 

 — Bocconia stamens — Mode in ray florets — Rain leaves — Wind and 

 leaves— Mechanical tissue and strains — Dust— Organic materials— 

 Rain-catching arrangements i8i 



CHAPTER XVII 



VEGETABLE AND ANIMAL 



Forests and man — Nettles— Loranthus in Australia — Mimicry in carboni- 

 ferous period — Grasshopper and grass stems — Worms— Open floras 

 and change by animals in Tundra, Patagonia, and Heathermoors — 

 Poisonous Australian plants — Equisetums — Fungi of animal manure 

 — Spruce gall insect— Aphid and its enemies— Nepenthes bical- 

 carala and its ants— Sunbirds — Elephants and Rafilesia- Ants and 

 seeds 195 



CHAPTER XVIII 



ANTS AND MITES 



Mite caverns in leaves— Inheritance of mite injuries — Spruce and ant 

 plants — Stipule thorns and ants— Galleries in ferns — Nectaries on 

 leaves— Leaf-cutting and fungus-cultivating ants— Ant gardens in 

 the Amazons ..,.., 205 



CHAPTER XIX 



ELECTRICITY — RADIUM, N- AND X-RAYS 



Electric potential of air— Currents of electricity in plants — Reactions on 

 stimulation — Increased assimilation — Roots and electric currents — 

 Nollet's, Bertholet's, and Speschnew systems — Thwaite's experi- 

 ments — Electrocution of plants — Damage to trees and bacteria — 

 Lilac in electric light — Rontgen and radium rays — Dr. Russell's 

 photographs — N-rays . . . . . . . . .211 



CHAPTER XX 



ORIGIN OF OUR BRITISH FLORA 



Flora of France before the Ice Age — Invasion of Northern Ice — 

 Separation of Alpine districts — Cardamine — Glacial boulder-clay 

 — Climate of Ice Age — Dryas, birch, Scotch pine and oak floras — 

 Succession of and upper limits of these associations — Botanical 

 survey maps — Reid's and Lewis' researches — Peatmoss investiga- 

 tions — Climatic changes — Hazel in Sweden — Preglacial English 

 plants — Geikie's Ice Ages — Tacitus and historical forests — Age of 

 destruction — Weeds — Beech mvasion — Cornish heath and Spanish 

 plants — Irish Americans — Cinnamons 218 



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