692 



Index 



Allosaurus, 614 

 All-or-none law, 125, 173, 208 

 Alosa, 590 

 Alouatta, 630, 635 

 Altitude, 157 

 Altricial birds, 621 

 Alveolus, 62, 149, 153, 156 

 Alytes, 596, 599 

 Amblyopsis speleus, 590 

 Ambulacral groove, 543, 545, 551, 553 

 Ambystoma, 567, 596, 597 

 A-mbystomidae, 596 

 Ameiurus, 590 

 Ametabola, 520 

 Amia, 569, 582, 590 

 Amino acid, 32, 138, 228 

 Amioidea, 590 

 Amitosis, 272 

 Ammocoetes, 573 

 Ammonia, 186, 191, 320 

 Amnion, 290-291 

 Amniote, 290 

 Amniotic cavity, 285 

 fluid, 290 

 sac, 290 

 Amoeba, 352 



proteus, 359-361 

 Amoebic dysentery, 362 

 Amoebocyte, 376, 458, 519, 525, 543, 



546, 552 

 Amoeboid movement, 177, 359, 363 

 Amphibia, 595, 601 (see also Frog) 

 biology, 597-601 

 characteristics, 595-596 

 circulation, 161, 166 

 classification, 46, 47, 559, 561, 567, 



596 

 embryology, 281 

 endocrines, 247 

 integument, 77, 78, 82 

 nervous system, 195 

 origin of, 568, 569 

 respiration, 148, 149 

 sense organs, 219 

 urinary system, 185 

 Amphiblastula, 380 

 Amphineura, 468-469 

 Amphioxus, 564-566 

 classification, 561 

 egg, 283 



embryology, 280-282 

 Amphipod, 507 

 Amphitrite, 449, 454 

 Amphiuma, 596, 598 

 Amphiumidae, 596 

 Ampulla, 223, 224 



of echinoderm, 543, 546 

 Amyda, 605, 606 

 Amylase, 139 



Anabolism, 24, 127 

 Anaconda, 610 

 Anaerobiasis, 154 

 Anaerobic reaction, 121, 122 



process, 153 

 Anal canal, 135 

 plate, 523 

 pore, 398, 400 

 vesicle, 464 

 Analogy, 112, 323 

 Anaphase, 271 

 Anapsida, 603 

 Anastomosis, 171 

 Anatomical terms, 51 

 Anatomy, 21 



comparative, 323 

 Anchitherium, 333 

 Ancylostoma braziliense, 434 



duodenale, 432, 434 

 Androgenic hormones, 241 

 Anemia, 178 

 Angler fish, 589, 590 

 Anguilla, 587, 589, 590 

 Anguina, 430 

 Angulosplenial bone, 57 

 Ani, 625 

 Animal kingdom, 44, 344-348 



pole, 280 

 Anion, 27 

 Ankle, 110 

 Ankylosaurus, 614 



Annelida, 45, 446-465 (see also Earth- 

 worm) 

 characteristics, 446-449 

 classes, 449 

 classification, 348 

 circulation, 159 

 nervous system, 192 

 respiration, 147, 148 

 Annulus ventralis, 504 

 Anodonta, 472-476 

 anatomy, 472-475 

 circulation, 473-474 

 life history, 475-476 

 Anolis, 607 

 Anopheles, 365 

 Anoplura, 539 

 Anostraca, 506 

 Anseriformes, 625 

 Ant, 533-534, 539 

 Ant lion, 539 



Antagonistic group of muscles, 68, 118 

 Anteater, 130, 630, 635 

 Antedon, 544, 553 

 Antelope, 88, 640 



Antenna, of Cambarus. 495, 496, 498 

 of insects, 212, 519, 522 

 of Peripatus, 490 

 Antennule, 495, 496, 498 



