Contents 



CHAPTER XXVI 



THEORY OF PLANT-BREEDING 



PAGF 



Acquired characters — Desert plants — Little species of Lamarck — Supply 

 and demand in the plant — American trotting-horse — Germ plasmas 

 and Begonia — Mutation — CEnothera Lamarckiana — Double flowers 

 — Fasciation — Physiological state — Mendel and his experiments 

 — Presence and absence of colour — Miss Saunders' stocks — Hurst's 

 tomatoes — Dominance — Pollen parent affecting colour — Iris with 

 six stamens — Grafting and its effects ...... 295 



CHAPTER XXVII 



SCRUB 



Thorny acacias — Maqui — Gum-cistus— Scented labiates — Garigue — 

 Wild-olive woods of Spain — Sheep in Spain — Moors and slave- 

 labour — Mediterranean cultivation — Goats and other animals — 

 Balearic islands — Gums and perfumes — Flower industry— Mos- 

 quitoes and basil — Ethereal oils and their importance — Cape 

 Colony, Australian, Califomian and Chilean scrub . . . 307 



CHAPTER XXVIII 



TROPICAL FORESTS 



Wet jungle of West Africa — Elephant grass — Leaf-stories in the jungle 

 — Animal life — Insects— South Mexican forest — Rubber and its 

 collection — Rubber plantations — Oil palms — Mosquito and malaria 

 — Extending cultivation — Fires in Nigeria — Mangrove forest — 

 Seedlings of Rhizophora — Colonisation of mud . . , .316 



CHAPTER XXIX 



ON EVIL IN SMALL DOSES 



Origin of variations — Biometrical researches — Pure lines — Sugarbeet — 

 Roots and carbonic acid — Salt on plants — Mineral poisons — Alcohol 

 and ether — Electricity — Heat and cold — Gladiolus bulbs and 

 wounds — Fungus and insect attacks — Palm leaves falling — Enzymes 

 — Miss Gibson and chrysanthemum fungus — Mr. Salmon's mildews 

 and bromes — Rusts and mildews — Infection of sickly plants — 

 Begonia and a cucumber fungus — Mycorhiza — Lichens — Insect 

 visits — Animal injuries — Effect of man — Students of Nature . . 327 



BIBLIOGRAPHY 338 



INDEX 348 



xiv 



