348 INDEX. 



D. 



Damping off, 149. 



Deciduous plants, 78 — trees, season for transplanting, 282. 



Degeneracy, means of preventing it in seed crops, 302. 



Degeneration of varieties, 302. 



Deleterious matter thrown off by roots, 20 — substances, when 

 attenuated, are most likely to prove injurious to plants, 18. 



Dew-point, 126. 



Digestion, a function of the leaves, 40. 



Diurnal rest of plants, 327. 



Drainage, 118 — of pots for plants, 119, 275 — of soil in pots by frag- 

 ments of absorbent stone, 275. 



Dryness, atmospheric, table of, with regard to the direction of the 

 wind, 133, 134 — causes of, in hothouses, 143. 



Double composite flowers, 315. ° 



Double Dahlias not truly double flowers, 316. 



Double flowers, 316 — conditions under which they may and may not 

 produce Beed, 173. 



Double pots employed for striking cuttings, 202 — for plants, 274. 



Double Stocks, 318. 



Dung-heat, Grapes and Nectarines forced by it, 146. 



Dwarfing trees, Chinese mode of, 261. 



E. 

 Earth, temperature of, at various places, 91, 92. 

 Earths, certain of them enter into the composition of the food of 



plants', 17. 

 Easterly winds, their dryness, 130. 

 Embryo buds, 30. 



Endogens, 24, 29 — mixed arrangement of their tissue, 29. 

 Envelopes, not a necessary part of a flower, 55. 

 Epidermis, in its young state, highly sensible to the stimulus ot 



light, 115 — regulateB the amount of perspiration, 53 — of leaves, 



88 — an extension of the outer bark of the stem, 40^oi' the 



leaves of evergreens, 285 — of plants inhabiting shaded situations, 



44. 

 Evaporation, an important vital function of plants, 125 — affected by 



elevation, 129 — affected by wind, 129 — from the surface of 



scions, 285. 



