Index 



Abstract sciences, 9 



Abyssal zone, 470 



Acid, 41 



Acromegaly, 363 



ACTH (adrenocorticotropic 



mone ) , 364 

 Addison's disease, 361 

 Adrenal glands, 360 

 African sleeping sickness, 95 

 All or none law, 318 

 Allantois, 383, 536 

 Alligators, 385 



Alternation of generations, 124 

 Altricial young, birds, 412 

 Amino acids, 58 

 Amnion, 383, 536 

 Amoeba, 85 

 Amoebic dysentery, 90 

 Amoeboid movement, 86 

 Amphibia, 378 

 Amphineura, 286 

 Amphioxus, 288, 305, 524 

 Anabolism, 21 

 Analogy, 187 

 Anatomy, 15 

 Ancestry, 501 

 Ancon sheep, 550 

 Annelids, 169 



Anopheles mosquito, 99, 166 

 Anoplura, 249 

 Ant bears, 449, 450 

 Ant lion, 253 

 Anthozoa, 129 

 Ants, 259 

 Apes, 454 

 Aphids, 251, 260 

 Aphis lion, 252 

 Appendages, crayfish, 185 

 Aptera, 240 

 Arachnoidea, 198 

 Archaeornis, 423, 424 



hor- 



Archenteron, 525 



Arctic tern, 413 



Aristotle, 488 



Armadillos, 449, 450 



Arrow worms, 268 



Arthropods, 181 



Artificial selection, 548 



Ascaris, 155 



Asexual reproduction, 70, 88, 111, 122 



Assassin bug, 250 



Asteroidea, 289 



Atom, 37 



Autonomic nervous system, 326 



Autotomy, 193, 294 



Aves, 404 



Axolotl, 380 



Balance, 328, 368 



Balanoglossus, 304 



Balantidium coli, 105 



Barn owl, 410, 417 



Barnacles, 194 



Basal metabolism, 21 



Base (alkali), 41 



Bats, 434 



Bears, 439 



Bedbugs, 250 



Bee flies, 256 



Beef tapeworm, 150 



Bees, 229, 236, 238, 259 



Bilateral symmetry, 134, 289 



Biological sciences, 9 



Biomes, 475 



Biramous appendage, 184 



Bird lice, 249 



Birds, 404 



Bison, 478 



Bivalve, 271 



Black snake, 398 



Black widow spider, 201 



Bladder worm, 150 



573 



