590 



INDEX. 



Hales, Dr., experiments on the eircnla- 

 tion of the 

 sap, 61 



the perspi- 

 ration of 

 plants, 65 



Heart wood, its formation, 40 



Heat acts as a stimulus to the vital 

 forces, 148 



amount of, uecessaiy for the strik- 



ing of cuttings, 290 



Boussingault's method of deter- 



mining what amount a plant 

 requires, 163 



■ cannot be transmitted downwards 



through water, 138 



degree of, best suited for cuttings, 



282 

 degree of, most conducive to vege- 

 tation variable, 15 



high degree of, required by certain 



plants at particular seasons, 153 



its agency in changing the secre- 



tions of fruit, 100 



its effect in causing the foimation 



of pollen, 108 



necessary to produce germination, 



14 



necessity of adjusting, in the strik- 

 ing of cuttings, 289 



produces a distention of all the 



organic parts, 15 



sets the vital principle in motion, 16 



the stimulus of excitability, 114 



unusual degree of, injurious in the 



striking of cuttings, 291 

 Heating by hot-water pipes preferable to 



flues, 207 

 Heaths, mode of striking, by cuttings, 298 



much heat injurious to, 299 



Heel, a term applied to the part of a 



scion that is sometimes left in certain 

 cases of grafting, 340 

 Herbaceous grafting, mode of operating, 

 and precautions necessary to ensure 

 success, 321 

 Himalayas, temperature of, 122 

 Horizontal plane, bad effects of training 

 on one, 423 



system of stems, 85 



systems of stocks and scions, 



necessity for their corre- 

 spondence in growth, 351 

 Horn shavings as manure, 665 

 Hot bed, its utility in the striking of 



cuttings, 285, 288 

 Hothouses, bad effects of a high night 

 temperature in, 208 



. . cause of atmospheric dryness 



in, 207 



Hothouses, important that the night 

 temperature should be lower than 

 that of the day, 514 

 Hot springs, their effects on surrounding 



vegetation, 135 

 Hunt, Mr., his enquiries into the effects 



of coloured glass on plants, 238, 300 

 Humus, of what composed, 526, 528 

 Hyacinths, remarks on theii- management, 



165 

 Hybrids are often sterile, 96 



may be fertile, 493 



■ their origin, 96 



their precocity and power of 



enduring cold, 489 



Hybridising, Gasrtner's conclusions on, 



490, 498 



greater proportion of plants 



not susceptible of, 600 



points to beconsideredin,488 



practical instructions for, 



490, 498 



■ precautions to be taken in, 



494, 498 

 Hydrogen fixed in the tissue of plants, 14 

 derivation of its supply, 28 



Hygrometers, and their mode of appli- 

 cation, 178, 184 

 Hymen inarching, 326 



Impossible grafts, 347 

 Impostors' graft, 348 

 Inarching, 322, 325 



as performed by the French on 



pear-tree branches, 323 



circumstances conducive to its 



success, 323 



mode of operating, 323 



India, difference between the night and 

 day temperature in, 514 



earth temperature in the peninsula 



of, 124 

 India-rubber bandages, use of, ingrafting, 



340 

 Inner bark, 35 

 Inscription, ancient one covered over by 



young wood, 39 

 Insects conduce to fertilisation, 241 

 Inverted J. budding, 312 

 Iodine, its power in stopping the motion 



of confervse, 10 

 Irritability of certain plants, 11 

 Ivy, origin of the tree, 481 



Jasmine, curious instance of variegation 

 in, 358 



Knaurs, analogous to propagating by 



seed, 268 

 propagation by, 44, 268 



