Vlll 



CONTENTS 



(IV) B. Angiosperms 

 Stem 



Root . , 

 Leaf 



. . .238 

 . . .239 

 ... 247 

 ... 250 



Flower 251 



Stamen 256 



Carpel 260 



Female gametophyte . 264 

 Male gametophyte . . 267 

 Fertilization .... 268 

 Endosperm .... 270 



Embryo 271 



Parthenogenesis . . . 275 

 Polyembryony . . .275 



CHAPTER PAGE 



(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 . . 45 1 



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 



