Vlll 



CONTENTS 



CHAPTER 



(IV) B. Angiosperms 

 Stem . , 

 Root . , 

 Leaf 



PAGE 

 .238 

 239 

 . 247 

 2 5 



Flower 251 



Stamen 256 



Carpel 260 



Female gametophyte . 264 

 Male gametophyte . . 267 

 Fertilization .... 268 

 Endosperm .... 270 

 Embryo ..... 271 

 Parthenogenesis . . . 275 

 Polyembryony . . . 275 



(IV) Classification .... 276 



Monocotyledons . . 276 

 Archichlamydeae . 279 

 Sympetalae .... 280 



V. Organic Evolution 283 



Environment 284 



Use and disuse 284 



Natural selection . .... 285 



Mutation 288 



Orthogenesis 289 



Weismannism 290 



Isolation 292 



Mendel's law 292 



Heredity 293 



PART II. PHYSIOLOGY 



Introduction 295 



L The material income of plants 297 



1. The plant cell .... 297 



2. Diffusion and osmosis . 302 



3. Turgor and its conse- 



quences . . . . . 308 



4. The permeable regions of 



root and shoot . . .311 

 II. The material outgo of plants . 323 



1. Transpiration .... 323 



2. Exudation of water . . 332 



3. The movement of water 341 



4. Other losses 352 



III. Nutrition 356 



1. The nature of plant food 356 



2. Photosynthesis. . . . 363 



(1) The raw materials . 364 



(2) The laboratories . 366 



(3) The energy . . .368 



(4) The products and 



the process . . 373 



3. The synthesis of proteins 377 



4. Other ways of getting 



food . . . . . .380 



(III) 5. The storage and translo- 



cation of food . . . 388 



6. Digestion 397 



IV. Destructive metabolism . . 403 



1. Respiration . . . . . 403 



2. Fermentations .... 409 



3. Waste products and ash 412 

 V. Growth and movement . . .417 



1. Growth 417 



2. Irritability 426 



3. Morphogenic stimuli . . 435 



4. Nastic curvatures . . . 442 



5. Locomotion and stream- 



ing 444 



6. Turgor movements . .451 



7. Tropisms 458 



(1) Geotropism . . . 459 



(2) Thigmotropism . . 469 



(3) Traumatropism . . 472 



(4) Rheotropism . . 473 



(5) Chemotropism . . 473 



(6) Phototropism . . 475 



(7) Other tropisms with 



radiant energy . 479 



8. The death of plants . . 480 



