472 



Index 



Hybrid lilies, 440 

 Hybrids, characters, 440 

 Hydrolysis, 217 

 Hydrophytes, 464 

 Hydrotropism, 239, 240 

 Hj'grometers and bygroscopes, 189 

 Hygroscopic movements, 385 

 Hygroscopicity, explained, 188; move- 

 ments of, 189 

 Hypocotyl, 354 

 Hypothesis, use of, 32 

 Hysterophytes, 465 



Imbibition, explained, 178; 187, 215 



Immunity, 273 



Improvement, illustration, 428; hypo- 

 thetical case, 434 



Inbreeding, 438 



Incidental phenomena, 347 



Indian Pipe, 453 



Indigo, 119 



Initial cell, 353 



Insanity, 357 



Insectivorous plants, 69, 194, 245, 

 464 



Insect pollination, 309, 461 



Insect traps, 69 



Insects, and flowers, 317, 323; resem- 

 bling seeds, 399 



Intelligence in Man, 14; in Nature, 14 



Intercellular system, 190 



Internodes, explained, 61 



Invertase, 129 



Iodine test for starch, 23, 109 



Iris, flower, 316 



Irish Moss, 447 



Irritability, 145, 148; nature of, 224; 

 227; elements in, 227; nature of re- 

 sponses, 229; stimulus, 229; localized 

 perception, 234; motor mechanism, 

 228; vs. heredity, 237; in plant im- 

 provement, 431 



Isolation of biotj^pes, 432 



Ivory Palm, 112, 156; cellulose of, 

 113 



Japanese Air-plant, 458 

 Juvenescence, 301 



Kelps, 447 

 Kerner, 314, 401 

 Knuth, 314 



Laboratory methods, value of, 138 



Lamarck, biography, 412 



Lathyrus Aphaca, 68 



Leaf fall, 40 



Leaves, anatomy, 19, 21, Plate I; weight, 

 25; why exist, 50; characteristics, 51; 

 parts, 52 ; typical, 53 ; variety of shapes, 

 53, 54; typical shapes, 55, 56; con- 

 ventionalizations, 57; terminology of 

 shapes, 58; emarginations, 59; com- 

 pounding, 59; lobing, 60; gas move- 

 ments in, 84; sizes, 65, 258; compound- 

 ing, 259; thickness, 259 



Leaf mosaics, 233; 235 



Lecithins, 117 



Lenticels, 191 



Leucoplastids, 160 



Lichens, 451 



Life, nature, viii, 13, 14; characteristics 

 of, 95; in relation to carbon, 96; energy 

 changes, 104, 134; two elements in, 

 144; origin of, 96, 149; cycles, 163; 

 rejuvenation, 163 



Life in relation to carbon, 96; all earth 

 can support, 104 



Life-plants, 392 



Light, nature, 32; use in photos3'nthesis, 

 34, 48, 50; on autumn color, 148; ad- 

 justment to, 224, 225, 235; protec- 

 tion against, 256, 261; and growth, 

 334 



Light screens, 39, 43, 262, 455 



Lignin, 113, 157 



Linaria Cymbalaria, 237 



Linden, fruits, 389 



Linna;a, 326 



Linnaeus, quoted, 11 



Lipase, 128 



Liquors, origin, 98 



Liverworts, 393, 454 



Living Oats, 385 



Living plant, an energy station, 198 



Living protoplasm, chemistry, 106, 130 



Locomotion of plants, 304, 379 



