598 



INDEX. 



Races of plaats, means of fixing their 

 habits, 464 



means of their preserva- 

 tion by seeds, 463 



origin of, 485 



theory of wearing out 



erroneous, 478 

 Radiation, 162, 194 



nocturnal, 199 



Radicle, 16 



Rain, average depth of, near London, 29 

 Rain-water, substances found in, 28, 29 

 Raspberry, period of ripening changed by 

 pruning, 365 



pruning of, 394 



Receipts for making grafting wax, 340 

 Repotting, 434 



Reproduction, property of, in leaf-buds 



and seeds, 13 

 Respiration, a function performed by the 

 leaves of plants, 59 



M. Pepy's experiments on, 61 



impeded, the cause of death 



to seeds that germinate in 

 water, 227 

 Rest of plants, 159 



diurnal, 513 



■ how effected, 511 



-— • in tropical regions how 



imitated, 511 



periods of, in tropical 



regions, 507 

 Resting plants, 607 



Rhododendrons, difBculty of cultivating 

 those from Siktim- 

 Himalaya, 220 



grafting of, 347 



injured when permitted 



to ripen seed, 98 



■ — their natural habits, 535 



Rind, 39 



Ringing, an operation by which the pro- 

 duction of roots is accelerated, 

 25 



effects of, 372 



experiments on, 48 



induces fructification, 94 



its ultimate consequences, 372 



permanent, not always injurious, 



371 

 physiological nature of the ope- 

 ration, 370 



proper seasons for, 371, 372 



substitute for, in Malta, 372 



Ripening of seeds, the effects of, 243 

 Root, at first grows by a general disten- 

 tion of its tissue, 17 



is the part soonest developed, 17 



its proportion to the stem variable, 



26 



Root, mode of its increase in length after 

 passing the embryo state, 17 



offices of its bark, 18 



substance from which it derives its 



means of accretion, 16 

 — ^ crops, manure for and mode of 

 application, 578 



excretions, theory of, abandoned, 30 



pruning, an old practice, 369 



as performed by the Chi- 

 nese, 368 



■ its effects in inducing fruit- 

 fulness, 367 



season for, 367 



Root watering, substitute for, 462 

 Roots, absorb whatever is fluid and suf- 

 ficiently attenuated, 27 



are naturally placed in a higher 



mean temperature than branches 

 and leaves, 148 



augment in diameter simulta- 



neously with the stem, 21 



aerial, phenomenon of, 141 



bad effects of their being deeply 



covered with soil, 140 



bruised, necessity of removing, 



367, 460 



■ can generate buds, 32 



cause of their formation, 25 



cause of their production in the 



stems of vines, 140 



cork-screw, formed from being 



confined in pots, 440 

 — — • differ from branches in not being 

 the development of previously 

 formed buds, 25 



effects of their being in a widely 



different temperature from that 

 of the branches, 69 



emitted into the air, 284 



employment of, as stocks for 



grafting on, 350 



feed on water, 29 



growing in water, 21 



— — have no greater power of excreting 

 matter than other parts of a 

 plant, 30 



in general have no buds, 30 



instances of, bleeding, 50 



of excessive develop- 

 ment of, 20 



of, forming layers of 



wood without the ex- 

 istence of a stem, 261 



of leaves producing, 



without forming buds, 

 278 



■ of, increasing in bulk 



without leaves, 74, 

 76 



