268 
Defiowering defined, 235. 
Defruiting defined, 235. 
Density, pruning for, 240. 
Depth of roots in soil, 73. 
Destruction of terminal buds by cold, 
116. 
Detasseling, 234, 242. 
Devices for transplanting, 227. 
Dew point, how to compute the, 124; 
table for computing, 123. 
Dibber, 227. 
Dicotyledones defined, 34. 
Diffusion, law of, 45. 
Diccious flowers, 97. 
Disbudding defined, 235. 
Disease defined, 13. 
Distal defined, 76. 
Dodder of clover and flax, 165. 
Domestic plants and animals defined, 
11. F 
Dormant state of protoplasm, 14. 
Drainage promotes soil aeration, 66; 
required by potted plants, 67. 
Dressing defined, 234. 
Drought causes toughness of plant tis- 
sue, 132; cultivation a preventive of, 
133; mulching a preventive of, 133; 
tends to hasten maturity, 132. 
Drying kills plant tissues, 134. 
Duration of germinating power, 101; of 
seed vitality, conditions affecting, 102. 
Electric arc light, use of, in glass houses, 
137. 
Elements essential in plant food, 42 
part played by different, 42. 
Emasculation of flowers, 255. 
Embryo defined, 38. 
Endosperm defined, 38. 
Enviroument defined, 10; factors of, 110. 
Epidermis defined, 46; replaced by bark 
in older stems, 47. 
Evaporation current, 57. 
Evergreen trees destroyed by untimely 
warm weather in spring, 111. 
Evolution, theory of, 20. 
Factors of environment, 110. 
Families, how formed, 18. 
Principles of Plant Culture. 
Farm manure, 146. 
Fecundation, 95; ecross-, how accom- 
plished, 254. 
Feebleness defined, 12. 
Ferns, how grown from spores, 37. 
Fertilization, 95. 
Fertilizer requirements of crops, 146. 
Filament, 91. 
Fir tree oil, 156. 
Fibro-vascular bundles, 49. 
Fixing desirable variations, 250. 
Flax, dodder of, 165. 
Flower, 90; certain parts of, often want- 
ing, 93; parts of the, 90; parts of, vary 
in form in different species, 92. 
Flower-buds, 84; conditions affecting 
formation of, 86; destroyed by cold, 
118; how distinguished from leaf-buds, 
84; ringing often causes formation 
of, 89. 
Flowering and fruiting, root pruning to 
promote, 245. 
Flowering glumes, 94. 
Flowering, pinching to promote, 244. 
Flowers, composite, 93; especially sen- 
sitive to cold, 118; of the grass fam- 
ily, 94; tend to exhaust the plant, 90. 
Flowers and fruit, obstructing growth 
current to promote, 245; pruning for, 
244. 
Flow of sap in spring, 58. 
Food, current of assimilated, 59; ele- 
ments of, most iikely to be deficient 
in the soil, 142; materials of, how dis- 
tributed through plant, 45; reserve, 
15; storage of reserve, 60; use of re- 
serve, 61. 
Food supply, insufficient, dwarfs the 
plant, 141; relation of roots to, 75; 
unfavorable, effect of, on the plant, 
140. 
Formative pruning, 237. 
Formula for Bordeaux mixture, 169. 
Formulas for kerosene emulsion, 154, 
155; for resin washes, 155, 156. 
Freezing of plants, favored by much 
water in plant tissue, 113. 
Freezing, severe, may split open tree 
trunks, 117. 
