586 



INDEX. 



Deciduous trees, season for transplanting, 



447 

 Degeneracy, means of preventing, in seed 

 crops, 468 



of races negatived, 475 



■ of varieties, no foundation 



for, 269, 471 

 Delacroix's method of propagating by- 

 cuttings, 296 

 Deleterious matter, when attenuated, is 

 most likely to prove injurious to roots, 

 27 

 Denmark, temperature of, 120 

 Deodar, grafting of, 347 

 Development of leaves, 65 

 Dew point, tables of, 182, 183 

 Dicotyledonous trees, 41 

 Digestion a function of the leaves of 

 plants, 69 



, rate of, in a healthy plant, 73 



Disease, renewal by seed not always a 



preventative of, 474 

 r the manner in which it is pro- 

 pagated, 480 

 Diurnal rest of plants, 613 

 Double bell-glasses for cuttings injurious 



rather than beneficial, 296 

 Double composite flowers, 601 



dahlias not truly double flowers, 



601 



■ flowers, supposed to arise from a 



debilitating process, 601 



tendency in some plants 



to produce, 602 



conditions under which 



they may, and may not 

 produce seed, 242 



their origin, 82, 601 



■ stocks, mode of producing, 503 



yellow rose, effect of budding it, 



303 

 Drain pipes, instance of roots choking, 



20 

 Drainage, advantages derived from, 137 



. effects of, 169 



essential for plants grown in 



pots, 437 



experiments relating to, 138 



. importance of, 170 



modes of effecting, 438 



necessity for, in the striking of 



cuttings, 287 

 - probable rationale of, 170 



Drained land much warmer than water- 

 logged land, 137 



Drains, ventilation by, 226 



Dryness, atmospheric, table of, with re- 

 gard to the direction of the 

 wind, 190, 191 



causes of, in hothouses, 207 



Dryness, complete, necessary in the pre- 

 serving of seeds, 244 



mean degree of, during the au- 



tumnal months near London, 



454 

 table of average degree of, in 



the middle of the day, 189 

 though favourable to seeds, is 



prejudicial to plants, 254 



though fatal to plants in a state 



of growth, is beneficial while 

 ripening their fruit, 192 

 Dung heat, grapes and nectarines forced 



by, 210 

 Durand, M., his experiments to show that 



trees may increase in bulk vrithout 



leaves, 75 

 Dutrochet, M., his experiments on the 



circulation of fluid in plants, 9 

 Dwarfing trees, Chinese method of, 368 



Earth-boeeb, and mode of using it, 579 

 Earth, mean temperature of, in various 



parts of the world, 117 — 125 

 mean temperature of, relation it 



bears to that of the air, 130 



temperature of, most favourable 



for germination, 230 

 Earth temperature, India, 129 

 London, 128 



Earths, certain of them enter into the 

 food of plants, 28 



Earthing up, its great utility in certain 

 cases of grafting, 340 



Easterly winds, their dryness, 186 



Edwards and Colin, M.M., their experi- 

 ments on the 

 temperature 

 bornebyoer- 

 tain seeds, 

 231 



their experi- 

 ments on the 

 earlyproper- 

 ties of plants 

 raised from 

 small seed, 

 466 



Elective affinity, 499 



Electrical action, 15 



Electricity has no discoverable influence 

 on vegetation, 236 



Embryo buds, 44 



Endogens, 35, 43 



mixed arrangement of their 



tissue, 35 



Eridosmose, 62, 240 



Ennobling, 356 



Envelopes, not a necessary part of the 

 flower, 81 



