596 



INDEX. 



Plants, health of, ia in propoHion to the 



health of leaves, 72 

 — — — ■ imbibe an excess of fluid during 



the night, 69 



improved by cultivation, have a 



tendency to revert to their 

 wild state, 465, 505 



in a state of growth, require an 



abundant supply of moisture, 

 164 



injured by excess of water, 137 



in numerous instances have no 



predilection for soil, 636 



in sitting rooms, impossibility of 



preserving long in a healthy 

 state, 211 



irritability of, 11 



leafless, offices of leaves performed 



by the rind and epidermis, 34, 

 59 



liable to injury from contact with 



deleterious matter, 27 



like animals have their diurnal 



seasons of rest and repose, 

 114 ■ 



list of such as require to be 



" earthed up " when grafted, 



341 



I longevity of, 42 



. maintain the air in a fit state for 



the respiration of animals, 42, 



62 



may possess an inherent power 



of growth without leaves, 75 



natural food of, 28, 551 



natural mode that some have of 



propagating, 473 



occasionally formed from " eyes " 



separating from the mother 

 stem, 264 



occasionally inoreasedby cuttings 



of the midrib of their leaves, 

 280 



of extreme climates, 153 



packing of, in Wardian cases for a 



long sea voyage, 257 

 , — perennial, are renovated annually, 



472 

 — : — plunging of potted, 436 



possess some quality analogous 



to animal irritability, 295 

 -. power of producing roots from 



various parts, 21 



. power to select their food, 27 



, probable cause of the difficulty of 



cultivating alpine, 218 



prolonged vitality of, 262 



^ raised from small-sized seeds, 



supposed to be earlier than 



those from large seed, 466 



Plants require the soil and atmosphere 

 to correspond in tempeiatvire 

 with that of the countries of 

 which they are natives, 136 



should never have more moisture 



than they can consume, 164 

 ■ species and varieties of, in their 



intrinsic qualities the same, 476 

 species of, appear to be eternal, 



471 

 ■ succulent, should be packed dry, 



257 



suffer from cold in proportion to 



the quantity of water they 

 contain, 111, 113 



that are frozen must be thawed 



gradually, 204 



that grow fast at night do not 



ripen their wood, 519 



that inhabit shady situations will 



not endure full exposure to 

 the sun, 62, 79 



the channel through which their 



ascending fluids are conducted, 

 40 



the theory of their wearing out 



erroneous, 478 



their diurnal rest, 518 



their healthiness depends on the 



free action of the leaves, 59 



their limit of enduring tem- 



perature, 106 



their natural resting, 611 



their rest necessary to flowering, 



513 



universally have a season of rest, 



507 



vital actions of, 5 



vital force in sensitive, 9 



Plug-grafting, and mode of performing, 336 

 Plum-tree, budding of, 306 

 pruning of, 388 



Plumule, 33 



derives its nourishment partly 



from the root and -partly 

 from the seed leaves, 33 

 Plunging of potted plants, 435 

 Poisonous substances, fatEkl to man, prove 



equally so to plants, 27 

 Poisons, alkaline and metallic, destructive 

 to plants, 27 



their effects on plants, 8 



Pollen, 81, 498 



agents which afiect its fertilising 



powers, 241 



deficiency of, a cause of sterility, 



240 



is conveyed to considerable dis- 



tances by wind and insects, 

 468 



