X SUMMARY OF CONTENTS 



II. Growth and Formation under Constant External Conditions 



a. Growth of the cell, 258. 



1. Growth, 258 ; formation, 259. 



2. Growth of the protoplasm, 259. 



3. Growth and formation of the cell-wall, 260. Origin of the cell-wall, 260. 



Surface growth, 260 ; mechanics, 261 ; apposition, 262 ; intussusception, 

 262; significance of turgor tension, 263. Growth in thickness, 265 ; cessation 

 of growth, 267 ; resume, 267. 



4. Cell-division, 267 ; nuclear division (mitosis), 268 ; cell-wall formation, 269 ; 



arrangement of walls, 269 ; amitosis, 271; extent of division, 271. 



b. Growth of the entire plant, 272. 



1. Somatophytes, asomatophytes, 273 ; embryonic growth, 273. Position and 



activity of the growing point, 273; shoot (symmetry, 275; form, 276); 

 leaf, 277 ; root, 279. Structure of the growing point, 279 ; simple cases, 279 ; 

 arrangement of cells at the shoot apex, 280 ; at the point of origin of the 

 leaf, 281 ; at the point of origin of the root, 283. Adventitious growing 

 points, 284. 



2. Growth in extent, 285. Longitudinal growth: — measurement of increase, 



286; distribution of growth (root, 287 ; shoot, 290; leaf, 292) ; rate, 293 ; 

 duration, 294. Growth in thickness, 294. 



3. Internal development. Evolution of cell- form, 296 (tissue tension, 297) ; 



cell-wall, 297 ; cell-contents, 297. 



III. Influence of External Conditions on Growth and Formation 



A. The non-living environment. 

 General observations, 298. 



1. Temperature, 299. Alteration in the rate of growth. Cardinal points of tem- 



perature, 299 ; supra-maximum, 300 ; infra-minimum, 300. Alteration in 

 form, 301. 



2. Light. Cardinal points, 302. 



a. Influence of the intensity of light. Influence on the rate of growth, 



303. Formative influences. Etiolation, 304; causes, 306; significance, 



306 ; other results, 307 ; form and structure, 307 ; correlative influences, 



307 ; colour, 308 ; juvenile forms, 308. 



b. Influence of the direction of light on polarity and symmetry, 310. 



c. Influence of the quaUty of light, 311. 



3. Gravity, 312 ; mass acceleration, 313 ; intensity, 3 13 ; direction, 313; morpho- 



genic results, 313 ; influence on growth, 314. 



4. Mechanical influences, 314. 



5. Influences of materials, 315; deficiency of nutrients, 315; oxygen, 316; 



poisons, 316 ; chemical stimuli, 317 ; water, 317. 



B. Other Organisms. 



Association, 320; parasites, 321; fungus galls, 321; insect galls, 321; symbiosis, 324. 



C. Parts of the same body 

 Correlations, 326. 



a. Evidence from observation, 327. 



b. Evidence from removal of parts, 327. Immediate results of wounding. 



Healing of wounds, 327 ; regeneration, 328 ; different types of reparation, 

 329 ; polarity in regeneration, 330 ; qualitative results, 330. 



c. Functional adaptation, 330. 



d. Transplantation, 332 ; in normal orientation, 332; in inverted orientation, 



332; on other species, 333; quantitative results, 334; quaUtative results, 334. 



e. Causes of correlations. Influences of materials, 335 ; in growth in thickness, 



335 ; in regeneration, 336. Mechanical influences. Mechanical theory 

 of leaf arrangement, 2,2,7 • 

 Conclusion : the facts determining plant form, 338. 



