INDEX 



Abdomen of spider, 147. 



Abomasum, 321. 



Aboral surface, 90. 



Adaptations to surroundings, 354. 



Agassiz, Louis, 379. 



Aggressive resemblances, 357. 



Alligators, 263, 264 ; characteristics 

 of, 265. 



Alpacas, 322. 



Alternation of generations in Aurelia 

 and campanularian hydroid, 60. 



Amblystoma, 239. 



Ambulacral grooves, 90. 



Ambulacral spines, 90. 



Amoeba, 10, 13, 360 ; structure of, 14 ; 

 locomotion of, 14 ; manner of eat- 

 ing, 15 ; elimination of waste mat- 

 ter, 15 ; breathing of, 16 ; sensation, 

 16. 



Amphibia, 229 ; characteristics of, 

 241 ; adaptations of, 242 ; relation- 

 ships of, 243 ; economic importance 

 of, 244 ; classification of, 245. 



Anaconda, 251. 



Animals, similarity of, to plants, 8, 9 ; 

 beginning of, 19 ; growth of, 21 ; as 

 machines, 23 ; classification of, 24, 

 28 ; distribution of, 371. 



Annulata, 75 ; classification of, 88. 



Anopheles, 184. 



Ant-eater, spiny, 312. 



Antennae, 157. 



Ants, 188, 189. 



Aortic arches of earthworm, 81. 



Apteryx, 292. 



Arachnida, 144 ; economic impor- 

 tance of, 152 ; characteristics of, 152. 



Archean, 342. 



Aristotle, 374. 



Armadillos, 315. 



Arthrop.oda, 124. 



Asexual reproduction, 362. 



Atoll, 58. 



Auks, 280 ; great, 280 ; nesting hab- 

 its of, 293. 

 Aurelia, 52 ; life history of, 53. 

 Axolotl, 244. 



Baboon, 333. 



Baer, Karl Ernst von, 378. 



Baleen, 317. 



Barbs, 271. 



Barbules, 271. 



Barnacles, 135. 



Basilisks, 375. 



Bats, 331 ; fruit-eating, 332 ; vam- 

 pire, 332. 



Bears, black, 324 ; grizzly, 325. 



Beavers, 328. 



Bees, 188 ; small carpenter, 193 ; 

 large carpenter, 193 ; leaf-cutter, 

 193 ; bumblebee, 193. 



Beetles, 186 ; Colorado potato, 187 ; 

 May, 187. 



Bilateral symmetry, 76. 



Bipinnaria, 100. 



Birds, 268; characteristics of, 292; 

 molting of, 292 ; incubation of, 292 ; 

 nesting habits of, 293 ; migration 

 of, 295 ; adaptations to environ- 

 ments, 296 ; economic importance 

 of, 297 ; classification of, 299 ; 

 fossil, 350. 



Bisexual reproduction, 363. 



Blastophaga, 196. 



Blister beetles, 188. 



Blowfly, 186. 



Blow hole, 318. 



Blubber, 318. 



Bluejay, 291. 



Boa constrictor, 251. 



Bobwhite, 286. 



Bonnet, 377. 



Bowfin, 217. 



Brachiolaria, 100. 



Brachiopods, 344. 



381 



