INDEX 



Pages with accompanying illustyations and diagrams arc indicated by italics. 



Abdomen, 114 



Abducens nerve, 223 



Abrading mechanisms, 154 



Absorption of foods, 164 



Abstract Biology, 431 



Accommodation in human eye, 22y 



Acetic acid, 42 



Acid, 12 



Acoelomate animals, 136 



Acquired characters, 320 



Acquired immunity, 84 



Actinozoa, 102, 103, 258, 261 



Active defense, 354 



Adaptations, 53, 347-385 



Adrenal glands, 204, 205, 271 



Adrenalin, 205 



Agamic reproduction, 192, 246, 248, 



249, 250, 297 

 Algae, 76-77 

 Alimentary canal, 273. See also Digestive 



canal. 

 Alkali, 12 



All-or-None Law, 236 

 Allelomorphic genes, 323 

 Alternative characters, 320 

 Alveoli, 171, 772 

 Ambulacral water system, 107 

 Amino-acids, 14, 42-43, 162-164 

 Amitosis, 306 

 Ammonia, 14 

 Amnion, 279 



Amoeba, 54, 55, 56-63, 72, 97-98, 295 

 Amoeba p-oteus, 54 

 Amoebic dysentery, 97 

 Amoeboid movement, 61, 62 

 Amphibia, 118, 119, 125, 168, j6g, 



188, 219, 26g, 296, 334, 403 



Amphibian brain, 21c) 



Amphibian heart, ijg, 409 



Amphimixis, yo, 71 



Amphineura, /// 



Amphioxus, 7/5, 116, 265-266 



Ampullx, 2SO, 2^2, 233 



Amylase, 163-164 



Anabolism, 40 



Anaerobe, 81, 87 



Anarsthesia, 236-237 



Anal spot, 67 



Anaphase, 310 



Anatomy, 39, 53 



Andalusian fowls, 330 



Animal Biology, 2, 39, 52, 251 



Animal cell, sg, 42 



Animal communities, 53, 377 



Animal digestive systems, 153, 410 



Animal distribution, 414-416 



Animal heat, 190 



Animal hemisphere, 267, 268 



Animal kingdom, 76, 95-97 



Animal nutrition, 42 



Animal pole, 267, 282 



Animal Sociology, 53 



Annelid circulatory system, lyj 



Annelid digestive system, 754, 155 



Annelid nervous system, 274 



Annelid respiratory system, 166 



Annelida, 96, 109, 770, 125, 7J9, 140, 



134, 155, 166, 213, 274, 249, 296 

 Anopheles, 74, 362 

 Anteater, 121 

 Antennae, 123, 359, j6o 

 Anterior, 7^4-135 

 Antero-posterior development, law of, 



283, 284 



463 



