424 



INDEX 



Dog's Mercury (Mercurialis peren- 



nis), leaf of, 37 (fig.), 59 (fig.), 



168, 169; petiole of, 113 (fig.). 

 Dogwood (Cornus sanguinea), galls 



of, 143 (fig.). 



Dominant characters, 384 et seq. 

 Dormant characters (of hybrids), 



382. 

 Dorsiventral leaves, structure of, 



98, 107-11 (figs.), 116, 295, 



341, 342 (fig.). 



Double chromosomes, 306. 

 Double fertilisation, 368. 

 Douglas Fir (Pseudotsuga douglasii], 



128, 129 ; cone of, 352 (fig.), 



353- 

 Dragon Tree (Dracesna), secondary 



thickening of, 133 (fig.), 134. 

 Draparnaldia, 197 (fig.). 

 Drosera, tentacles of, 150. 

 Drought, resistance to, 186, 191, 



205, 215, 269, 271. 

 Dry habitats, structural features of 



plants of, 38, 88, 92, 94, 96, 



in, 158-66. 

 " Dry rot " of timber (Merulius 



lacrymans), 252. 

 Duckweed (Lemna), 112, 260. 

 Dunes, 163. 

 Dwarf-males (of CEdogonium], 221 



(fig.), 223. 

 Dwarf -shoots (of Conifers), 335, 



336 (fig.), 337, 338. 

 Dyes, vegetable, 64, 126, 261. 

 Dynamite and Diatoms, 207. 



Eau de Cologne, 62. 



Eau de Javelle, 401 ; and lignified 

 walls, 32. 



Ebony (Diospyros), 126. 



Echeveria retusa, 365. 



Economic plants, 34, 35, 39, 43, 45, 

 48, 49, 53, 62, 103, 124, 126, 

 140, 155, 157, 203, 204, 207, 

 255, 256, 257, 261, 276, 323, 



334, 337, 352. 



Economic utilisation of, Algae, 203, 

 204 ; alkaloids, 61 ; Bacteria, 

 265 ; Bog-moss (Sphagnum), 

 276 ; Conifers, 127, 129, 334, 

 337, 352 ; cork, 136, 140 ; 

 Diatoms, 207 ; ethereal oils, 

 62 ; fats, 49 ; fibres, 34, 

 35; Fungi, 255, 256, 257; 

 glucosides, 48 ; gums, 39 ; 

 hairs, 103 ; latex, 155, 157 ; 

 Lichens, 261 ; starches, 43 ; 

 sugars, 45, 124; timber, 126, 



127-30 ; vegetable pigments, 

 64, 126. 



Economy of water, 158-66. 



Ectocarpus, 199 ; habitat of, 195 ; 

 sexual reproduction of, 212, 219 

 (fig.), 220 ; structure of, 198, 

 219 (fig.) ; zoospores of, 218, 

 219 (fig.). 



Ectocarpus littoralis, 219 (fig.). 



Ectotrophic mycorrhiza, 72. 



Edible plants, 43, 44, 45, 48, 49, 

 52, 53, 60, 203, 204, 255, 261, 

 352. 



Egg (ovum), 220 ; of Algae, 220, 

 221 (fig.), 222, 224, 226 ; of 

 Angiosperms, 357 (fig.), 366 

 (fig.), 367 (fig.), 368 ; of Coni- 

 fers, 348, 349 (fig.) ; of Cycads, 

 326, 327 (fig.) ; of Ferns, 302, 

 303 (fig.) ; of Fungi, 233 (fig.), 

 234, 236 ; of Liverworts, 280, 

 281 (fig.); of Mosses, 280; of 

 Selaginella, 319, 320 (fig.). 



Egg-apparatus (of Angiosperms), 

 366 (fig.). 



Elaborated food-material, conduc- 

 tion of, in Angiosperms, 28, 65, 

 88, no, in, 112; aquatics, 

 171 ; Conifers, 343 ; Mosses, 

 276 ; by laticiferous elements, 

 156 ; by the xylem, 124. 



Elceagnus, 103. 



Elasticity, of collenchyma, 31, 33 ; 

 of cork, 137 ; of fibres, 33 ; of 

 wood, 127, 128. 



Elaters (of Liverworts), 271 (fig.), 

 282, 283 (fig.). 



Elder (Sambucus), cork of, 136 

 (fig.) ; leaf of, no, in (fig.) ; 

 lenticels of, 140 (fig.) ; pith of, 

 30 (fig.), 151. 



Elm (Ulmus), 130, 139, 141, 365 ; 

 Cork , 141 ; secondary wood 

 of, 1 20, 126. 



Elodea canadensis, cell-structure, 

 5, 6 (fig.) ; spread of, in British 

 Isles, 392 (fig.). 



Elongation, zone of, in root, 65. 



Embryo of, Angiosperms, 367, 368- 

 72 (figs.) ; Conifers, 350-52 

 (fig.), 370 ; Cycads, 326, 327 

 (fig-), 332, 333 ; Dicotyledons, 

 368-71 (figs.) ; Ferns, 294, 

 302-4 (fig.) ; Fucus, 221 

 (fig.), 226 ; Liverworts, 282 ; 

 Monocotyledons, 370, 371 (fig.); 

 Mosses, 284, 285 (fig.) ; para- 

 sitic Angiosperms, 179, 372 ; 



