Index 



Abrasive action of medium, 53-58 

 Absorption of sun's rays by various 



media, 135-136 

 Abyssobenthic zone, 30 

 Aestivation, 121, 146-148 

 Age distribution, 344 

 Aggregation in response to temperature, 



157 

 Aggregations, see Groups 

 Agriolimax, tactic reactions, 214 

 Air, distribution by, 45-48 

 Alewife, orientation, 267 

 Algae, antagonistic substances of, 384 



depth in relation to light, 235-237 



in hot springs, 130 



on tree trunks, 118 



on turtle shells, 376 



zonation in tidal zone, 102-105 

 Alkalinity of natural waters, 263 

 Allen's rule, 157 

 Alpine plants, 160-162 



see also Life zones 

 Altitude 



effect on Oi; availability, 243 



effect on distribution of animals, 27- 

 29 



effect on temperature, 134 



effect on vegetation type, 175-179 



limitation of distribution by, 253 

 Altitudinal hfe zones, 175, 179 

 Aluminmii in pedalfer soils, 86-87 

 Amphibious environments, water prob- 

 lem in, 99-107 

 Anaerobic organisms, 243, 255, 258 

 Animal exclusion, theory of, 447 

 Antibiosis, 383-385 

 Ants, leaf-cutting, 372 



slave-making, 385 



symbiotic relationships in, 370-371 



territory in, 353-354 

 Aphids, 325, 370-371, 387 

 Aphotic zone, 241 

 Aquatic communities, stratification of, 



423-424 

 Association, 448 



Austausch coefficient, 248 

 Autecology, 14 

 Autotomy, 58 

 Autotrophic nutrition, 278 



Bacteria, 298 



antibiotics and, 383-384 



chemotrophic, 278 



commensal, 377 



effect of pressure, 31 



in soil, 77 



luminescent, 204 



symbiotic, 365-366, 368-369 



thermophilous, 130 



see also Decomposers, Decomposi- 

 tion, Nitrification, and Trans- 

 formers 

 Bactericidal effect of sunlight, 231 

 Balanoid zone, 104-105 

 Barnacles, setting of larvae, 60 



temperature as affecting distribution, 

 171 



zonation in, 104 

 Barriers, 428-429 

 Bass, 7 



Bass tapeworm, 390-392 

 Bathypelagic zone, 30 

 Bats, echo location by, 61 



hibernation in, 147 

 Beavers, 25, 495 



Bees, control of hive temperature, 322- 

 323 



orientation in, 215 

 Benthic division, 30 

 Benthos, 36 



Bergmann principle, 157 

 Bicarbonate, 263 

 Biocenose, 402 



see also Community 

 Biogeochemistry, 303 

 Biokmiinescence, 204-207 

 Biomass, 469-470 

 Biome, 448-451 

 Biothermal zones, 180 

 Biotic potential, 334 



523 



