xiv CONTENTS 



CHAPTER VIII 



Page 



Growth 138 



The production of new cells — Growing-points and their function 

 — Terminal growing-points — Lateral growing-point or cambium — 

 Differentiation. 



CHAPTER IX 



The Plant and Its Environment 154 



Stimulus and response — Temperature — Light — Gravity — Moisture 

 — Chemical substances — Living organisms. 



CHAPTER X 



Reproduction 182 



Asexual reproduction — Sexual reproduction — Pollination — Fertili- 

 zation — ^Seed development — The fruit — Seed dispersal — Seed 

 germination. 



CHAPTER XI 



Heredity and Variation 206 



Heredity — Variation — Laws of inheritance — Inheritance of 

 acquired characters — Mendel's law of inheritance — Unit characters 

 — Dominance — Segregation — Independent assortment — Mutation. 



CHAPTER XII 



Evolution 229 



Evidences for evolution — ^Lamarck's theory — Darwin's theory. 

 "Natural Selection" — De Vries's theory — Orthogenesis. 



CHAPTER XIII 



The Plant Kingdom 243 



Plants and animals — Forward steps in plant evolution — ^1. The 

 multicellular plant — 2. Differentiation — 3. Sexual reproduction — 

 4. Alternation of generations — 5. The invasion of the land — 6. 

 The evolution of the seed. — Plant classification — Nomenclature. 



CHAPTER XIV 



The Thallophyta 264 



Cyanophyceae or blue-green algae — Chlorophyceae or green algae 

 — Phaeophyceae or brown algae — ^Rhodophyceae or red algae — 

 Bacteria — Phycomycetes or alga-like fungi — Ascomycetes or 

 sac fungi — Basidiomycetes or basidia fungi — Lichens. 



CHAPTER XV 



The Bryophyta 311 



Alternation of generations — Multicellular sexual organs — Hepati- 

 cae or liverworts — Musci or mosses. 



