INDEX 



625 



Dorsal line, 179 



Dorsal nerve cord, 179 



Dorsal pores, 234 



Dorsal root, 333, 334 



Dorsal tubular nervous system, 313 



Dorsal vessels, 236, 237, 258 



Double circulation, 367 



Down, 405 



feathers, 405, 406 

 Dragon flies, 294, 542 

 Dreaming, 502 

 Drones, 296, 297 

 Drosophila. 549, 550, 569 

 Dryophantes tanata, gall, 291 

 Duckbill, 429, 431 

 Ducks, 414, 420, 423, 528 



beak, 412 



foot, 413 

 Duct, 467 



Ductless glands, 373-374, 492-493 

 Dugong, 441 

 Dujardin, 19, 32, 583 

 Dura mater, 375 

 Durant, W. J., 579 

 Dwarfness, 565 

 Dyad, 476 

 Dysentery, 88 

 Dytiscus, leg, 279 



E 



Ear, 336-338, 347, 375, 386, 389, 390, 407, 408, 

 428, 473 



fish, 360 



human, 336 

 Ear muscles, man, 647 

 Ears, planarian, 159 

 Earthworm, 52, 234-242, 491 

 Earwigs, 294 

 Ebers, George, 578 

 Ecdysis, 264 



(See also Molting) 

 Echidna, 430 



Echinococcus granulosus, 171 

 Echinodermata, 203-211, bib, 576 

 Echinoderms, 115, 19^-202, 465, 466, 469, 470, 



472, 490, 491, 494, 511 

 Echinohynchus ranae, 185 

 Echinoidea, 204, 206 

 Echinopluteus, 210 

 Echiurus pallassii, 252 

 Ecology, 5, 505-514 

 Economic importance, amphibians, 381 



annelids, 254 



birds, 423 



coelenterates, 155 



crayfish, 264 



Crustacea, 270 



ctenophores, 158 



earthworms, 242 



echinoderms, 210-211 



elasmobranchs, 347 



fishes, 364 



flatworms, 171, 177 



insects, 296-301 



Economic importance, lampreys and hagfishes 

 343 



lower chordates, 321 



mammals, 447 



moUusks, 230 



protozoa, 81-84, 88-91 



reptiles, 401 



sharks, 348 



spiders, 306-309 



sponges, 135 



starfishes, 202 



threadworms, 185 

 Ectoderm, 121-125, 129, 138, 143, 187, 196, 444, 



446 

 Ectoparasites, 525 

 Ectoplasm, 63-65, 66, 70, 85 

 Ectopterygoid, 398 

 Edentata, 429, 437 

 Edible snail, 223 

 Eel, 341 



electric, 534 



migration, 530 

 Eelworm, 178 

 Effector cells, 165 

 Effectors, 165, 243, 496, 498 

 Efferent impulse, 165, 333 

 Efferent path, 244, 333 

 Egestion, 33, 34, 37, 38, 65, 71, 104, 140, 163. 



181 

 Egg cells, 31, 45, 46, 118-120, 122, 476, 521. 

 556, 558, 560, 566-568, 583 



cestodes, 169, 176 



coelenterates, 151-153 



development of, in birds, 384, 385 



earthworm, 240, 241 



hydra, 137, 142 



mammals, 445 



metazoa, 107-108 



mussel, 218 



nematodes, 181 



origin of, 109-113 



planaria, 163-164 



sponges, 134 



starfish, 198 



types, 119 



vertebrate, 340 

 Egg-laying mammals, 429 

 Eggs, 108, 113, 476 



annelids, 251 



birds, 383, 384, 385, 418, 419 



bryozoa, 192 



bull snake, 394 



butterfly, 286 



cecilian, 373 



crayfish, 263 



Crustacea, 268, 269 



fish, 361, 362 



frog, 374, 378, 379 



grasshopper, 286 



hen, 383 



honeybee, 297 



humming bird, 418 



insects, 283 



mollusks, 229 



monotremes, 429 



