582 INDEX 



Agaricus (Psalliota) campestris (Mush- 

 room, Pasture Mushroom), 100, 259, 

 Agarum, 36, 37, 537 [282 



Agathis aiistralis (Kauri), 353 

 Agave (Sisal), 235, 270, 355, 366, 447 

 Age and area hypothesis, 177, 182-3, 209 



— of plants, 79, 205 



— of world, 128, 145 

 Aggregation of germules, 323 

 Agnew, A. D. Q., xix 

 Agriculture, 3, 551, 555-6, 560, 564, 

 — , earliest known, 254 [573-9 

 — , regions favourable to, 315 

 Agroclimatic analogues, 574, 576 

 Agropyron (Couch-grass), 248, 249, 361 



A. repens (Couch-grass), 222, 249 

 Agrostis, 364 



A. antarctica, 419 

 Aids to dispersal, 5, 97-125 

 Air cavity, no 



— currents, dispersal by, 99, 106, 418 

 ■ — dispersal in, 99-101, 163, 181 



— travel, dispersal by, 119, 120 

 — , upper, 100, loi 

 Airborne pathogens, 251 

 Akpatok Island, 537 

 Alabama, 160 

 Alaria, 36, 37, 536 



A. dolichorhachis, 534 

 Alaska, 382, 387, 388 

 • — , former land-bridge to, 171 

 — , ' ice-bloom ' in, 490 

 — , middle-arctic region in, 382, 3S7, 388 

 — , Potato grown in, 231 

 — , trees in, 543 

 Alberta, 343 



Alcohol, 255, 269, 270, 275 

 Alcoholic fermentation, 260-78 

 Alder, see AInus and A/nits glutinnsa 

 Ale, 260 

 Alectoria, 39=; 

 Alekhin, V. v., 23 

 Aleppo Oak, 274 



— Pine, see Pimis halepensis 

 Aleiirites (Tung, Tung oil), 235, 265 

 Alexopoulos, C. J., 74 

 Alfalfa, see Medicago sativa 

 Algae, 28-41, 14s, 146, 278-9, 422, 458, 



473 . 478, 48 1 , 485. 486, 489, 492-503 

 — , antarctic, 416, 417, 418, 538 

 — , arctic, 39, 478, 490, 520, 535, 536-8 

 — , arctic hydroseres and, 406 

 • — , attachment of, 475, 498, 514, 524 

 — , attachment organs of, 494, 503, 528 

 ■ — , belts in eulittoral, 495 

 — , benthic, 491, 492, 493, 494, 522, 538 

 — , biological types of, 527, 528 

 — , ' blooming ' of, 29, 480-2, 490, 520 

 — , brine, 502 



— , browsed by Molluscs, 524 

 — , calcareous, 495, 529, 538 



485, 



Algae, Cambrian, 131 

 cavern, 546 



depth of water inhabited by 

 486, 496, 503, 522, 530 

 dispersal of, 106, 117, 513, 514 

 drought-resistant, 534 

 economic use of, 38, 259, 278-9 

 epiphytic, 434, 492, 499-500, 524, 



530-3, 537 

 fossil, 1 3 1-2 



heat-tolerance of, 495, 499 

 life-forms of, 527-8 

 light relations of, 325, 474, 475, 495, 



496, 522 



littoral, 523, 526-7, 531, 550 

 living within shells etc., 494 

 manuring and, 524 

 marine, attachment of, 514, 528 

 — , conditions of life of, 508-29 

 — , distribution in depth, 39, 512, 537 

 — , dispersal of, 106, 107, 510, 513- 

 — , drying and, 526 [14 



— , dwarfed, 508 

 — , ecological grouping of, 528 

 — , light requirements of, 512-13 

 — , migration levels of, 522, 524 

 — , periodicity etc. of, 524, 528, 537 

 — , temperature relations of, 510 

 — , tropical, 458 

 — , zonation of, 526-7, 532 

 microhabitat conditions of, 322 

 nutrition of, 29, 32, 37, 39, 476 

 parasitic, 524 



periodicity of, 475-6, 528, 

 pH of water and, 510, 523 

 planktonic, 333, 486 

 pre-Cambrian, 129, 130, 146 

 as primary producers, 278-9 

 reproductive periods of, 510, 

 salt-marsh, 368, 369, 370 



tolerant, 502, 508-9 



seasonal maxima of, 481—2 



soil forms of, 304, 333 



snow-patches and, 405 



summer maxima of, 481 



symbiotic, 495, 524 



temperature relations of, 77, 499, 



510. 537 

 terrestrial, 29, 32, 34, 365, 464 

 water-blooms of, 29, 480, 481, 482, 

 490, 520 



— , wave action and, 495, 524, 525, 532 



Algal limestone, 130, 132, 279 



Algaroba, 258 



Algin, 38, 265 



Alien flora (aliens), 1 18, 1 19, 210, 219,466 



, strong competitors and, 221 



, survival of, 120, 220 



, undisturbed ground and, 220 



Alkanna, 274 



Alkali-grass, see Puccivellia 



531-2, 

 [537 



532 



