6i6 



INDEX 



Niger seed oil, 265 



Night temperature, plant distribution 



and, 77, 78 

 NIpafruticans, 457 

 Nitella (Stonewort), 503 

 Nitrate content of water. Algae and, 475, 



476, 524 

 Nitrates, 368, 475, 481, 515, 519 

 Nitrogen relations, 82, 303, 319 

 Node, 69 



Noinenclature, 24, 25 

 Non-drying oils, 235, 265-6 



fruiting, cultivation and, 218 



Nordhagen, R., 198 

 Norsemen, 181, 306 

 North Africa, 272 



— America, 77, 80, 102, 159, 170, 174, 



192, 235, 243, 259, 260, 262, 



264, 266, 349, 424, 448, 463 



516, 567 

 ' bad-lands ' of, 366 

 ' cold deserts ' of, 414 

 coniferous forests of, 343, 345, 



346^ 348-50 

 Cretaceous flora of, 150 

 deciduous summer forest of, 



337-41 

 Diatoms of, 486, 516, 520 



discovery of, 181 

 forest area of, 246 

 former climates of, 151 

 glaciation in, 157-8, 159, 162 

 grasslands of, 360, 361, 362 

 hot desert of, 449 

 Jurassic flora of, 149 

 lake-forest of, 349, 350 

 mixed forest of, 340-1 

 mountain forest of, 376-7 

 nunatak hypothesis and, 162-4 

 Pacific coast forest of, 348-9 

 plant diseases in, 251-2, 305, 306 

 — migration in, 153, 157, 161, 



171 

 savanna in, 444 

 seaweeds of, 525, 532, 533, 534, 



536 



separation from Europe of, 166 

 Trapa in, 160, 199 

 weeds in, 199, 249 

 and eastern Asia, similarities in 

 floras of, 167 



— Asia, glaciation in, 158 



— Atlantic discontinuous range (dis- 



tribution), 190, 192 



Ocean, 202, 342, 532 



facing slopes, 294, 295, 375, 376, 



398 



— Magnetic Pole, 167, 397, 398 



— Pacific discontinuous range (dis- 



tribution), 190, 192 



— — Ocean, 170 



North Polar Basin, 127, 491, 539 



— Pole, 99, 127, 154, 166, 170, 184, 



381,491 



— Sea, 531 



South American discontinuous 



range (distribution), 190, 192 

 Northern coniferous forest, 332, 343-50 



— Wood-rush, see Luziila confusa agg. 

 Northernmost forests, 343-5, 348 

 Northwest Territories, 391 



Norway, 347, 411 



— Pine, see Piniis resinosa 



— Spruce, see Picea abies 

 Norwegian Alps, 414 



— Lapland, 327, 344 



Nose and throat disorders, treatment of, 



264 

 Nostoc, colonies of, 28, 365 

 Nothofagus (Southern Beech), 171, 195, 



196, 353. 354 



A'^. antarctica (Southern Beech), 342 

 Nucleus {pi. nuclei), 28, 43, 178 

 Nudation, 323 



Nunatak hypothesis, 162-4, i97 

 Nuphar lutea (Yellow Water-lily), 108 

 Nutmeg (see also Myristica), 261 

 Nutrients, mineral, 301-2, 432, 519 

 — , soluble, 12, 301-2, 319 

 Nutrition, angiospermous, 69, 72 

 — , algal, 32, 35, 39, 475, 47^, 481, 520 

 Nuts, 258 

 Nux vomica, 263 

 Nyassa, Lake, 477 

 Nylon, 270 



Nymphaea (Water-lily), 325, 372, 463, 

 500 



A^. stellota, 87 

 Nymphaeaceae (Water-lily family), 504 



Oak, see Querciis 



Beech association, 333, 334 



— forests, mixed, 341 

 Oakwood, 334, 340 



Oasis, 3, 365, 376, 416, 449, 452, 454 

 Oat, Oats, see Avena, A. saliva, etc. 

 Obelia, 2 

 Ocean, average depth of, 538 



— currents, 107, 293, 510, 513-14, 519 

 — , euphotic zone of, 511 



— , light penetration into, 511 



— , temperature at various depths, 510 



— water, characteristics of, 507-12, 514 

 Oceania, 247, 267 



Oceanic climate (insular climate, mari- 

 time climate), II, 12, 174 



— element, 21 1 



— islands, 105, 206 



— province (pelagic), 511, 513, 514, 515 

 Ochroma lagopus s.l. (Balsa), 247 

 Ocotea rodioei (Greenheart), 247 

 Ocotillo, see Fottquiera splendens 



