Contents 



CHAPTER XXI 



CONIFERS 



PAGE 



Werchqjansk Polar coniferous forests Frozen soil Northern forests 

 Scotch pine British Columbian forests Larch in Europe Larch 

 disease Sequoia of California Monkey puzzle forests Primaeval 

 forest in Bohemia Highland woods Woodfloor plants Area of 

 forest in Britain Royal Commission Forestry prospects Labour 

 Finest Scotch conifers . 236 



CHAPTER XXII 



ARABLE LAND 



England before 1789 Nomadic agriculture King Alfred Irish system 

 Braunton Great Field Commons and Enclosures Preparation 

 of the land Origin of weeds Rate of travel Weeds reclaiming 

 clay Vicia orobus in Germany Times of flowering Underground 

 runners Thistles, electrocution and spraying Numbers of weeds 

 Production of Britain per acre Food-supply in war . . . 250 



CHAPTER XXIII 



GRASS 



Bamboos Australian grasses Rice and oats Shooting of grass 

 Tussocks Steppe grasses Flowering and colours Mechanical 

 system Hygroscopic awns and sheep- killing Prairies and fires 

 Effect of fires on trees Wasteful system of agriculture Grass 

 pasture Food value, vigour, method of growth, quickness of 

 development, germination, preferences and price of the various 

 grasses in pasture Mr. R. H. Elliot ...... 261 



CHAPTER XXIV 



FORTUNATE ISLANDS 



Utopias Cocoa-nut, banana and sago palm Teneriffe and Von Hum- 

 boldt Zones of vegetation Colonisation of lava flows and tree 

 branches Orchid seeds Shorea fruits travelling Bird migration 

 American seeds on the Hebrides Navigator seeds of the Pacific 

 Currents and floating seeds Development of new species in 

 islands Araucaria distribution Giant lobelias .... 274 



CHAPTER XXV 



PRACTICE OF PLANT-BREEDING 



Selection of best single seed Sea island cotton crisis Seven-leaved 

 clover Natural hybrids Fern mongrels Mr. Biffen's wheats 

 Orchid crosses Luther Burbank Prune-trees in a year and a half 

 Bonfires Walnut hybrids Spineless cacti Larch experiments 

 Effect of altitude on seed Sycamores and leaf fall \farying 

 conditions Potatoes in icehouse Degeneration of potatoes Fife 

 wheat 284 



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