(Italic numbers refer to illustrations or charts.) 



Abnormality and chromosomal aberra- 

 tions. 396 

 Acanthodian. 156, 160 

 Accessibility in geographic distribution, 



265-267 

 Acoela, 73 



Acquired characters, see Heredity 

 Actinopterygii, 158 

 Adaptation, for differing diets, 87 

 and dispersal. 273 

 of elephant, see Elephant 

 of embryo, 69 

 to environment, 9, 11-12, 358, 420- 



421.468.475 

 exogenous. 423, 424 

 of horse, see Horse 

 and natural selection. 499 

 and subpopulations, 486, 487-488 



See also Environment, changes in; 

 Postadaptation: Preadaptation 

 Adaptive peak, 11, 452,454, 455 

 Adaptive radiation, 26, 27, 28-29, 192, 

 264, 267, 290, 489 

 of drepanid birds, 297, 299. 488 

 of finch beaks, 294-296, 487-488 

 Adenylic acid, 90, 91, 497-498 

 Africa, animals of. 206-207. 210, 211, 

 225,258-261,267,271 



See also Australopithecines 

 Agar, W. E., 342. 343. 362 

 Age, see Geologic record; Geologic time 



scale; Senescence 

 Agouti, 119. 120.260 

 Agriculture, development of, 246 

 Air cells, see Diploe 

 Air sacs, 187 

 Albino, 104, 322, 349, 366, 433 



See also Pigment 

 Albumen, 169 

 Algae, 91 



fossils of. 137. 138, 145 

 AUantois. 5J.55. 6i. 93. 769 

 Allee, W. C, 276, 454, 481, 520, 522 

 Allen's rule, 276 

 Alligator. 194 

 Allison, A. C, 465,481 



527 



Allometry. 361, 405-418, 406. 409, 503 



negative, 413-414. 415 



positive, -^07, 413,414, 475 

 Alpaca, 270 

 Alpatov, 274 

 Amadon. D., 300, 301, 302, 303, 304, 



305, 488, 506 

 Amber, fossils in. 129 

 Amblypod. 796 

 America, see Central America; North 



America: South America 

 American Indians, 251 

 Amino acids, 86-87 



manufacture of, 85. 104 



rotation of polarized light by, 498 

 Ammonia, in plant nutrition, 84 



as waste product. 87. 91-94, 97 

 Ammonite. 166, 173-176, 174 



first. 137. 155,759 

 Amnion, 52. 53. 58. 168, 769, 797 

 Amniotic fluid, 58, 168 

 Amoeba, 71 

 Amphibia, 31 1 



See also Amphibians 

 Amphibians, 15-17, 57, 137, 164, 165- 

 166, 167, 176 



brain of. 32 



excretion by, 92, 100 



first, 137, 155 



limbs of, see Limbs 



on oceanic islands, 283 



osmotic regulation in, 99, 100 



skulls of, 31 



See also Frog; Labyrinthodontia; 

 Newt; Toad 

 Amphioxus, 48, 68, 707, 102, 311 

 Amphipod, 404-405 

 Analogy, 20-21, 25-26, 28-29. 313 



See also Convergent evolution 

 Anatomy, see Morphology 

 Anaximander, 3 

 Ancon ram, 337, 347 

 Anderson, E., 478, 479, 480, 481 

 Andrews, 212, 214 

 Anemia, sickle-cell, 465-466 

 Aneuploidy, 399 



