INDEX 



595 



Digestion, 32-34, 42, 05, 71, 102, 131, 138, 161, 

 168, 177, 196, 230, 246, 322, 323, 399, 46"0- 

 461 



Digestive enzymes, 13, 65, 86, 97, 131, 138, 230, 

 321, 323, 439, 461 



Digestive system, 102, 103, 158, 165, 190, 195, 

 204, 205, 210, 212, 232, 242, 245-246, 253, 

 276, 277, 297, 311, 314, 317, 321-323, 339, 

 350-351, 393, 394, 438-439, 544-545 

 (See also Alimentary canal) 



Digitigrade foot, 414 



Dihybrids, 532, 533 



Dimorphism, 443, 543 



Dinophilus, 243 



Dinosaurs, 390, 397, 398, 515 



Diphtheria, 491 



Diphycercal tail, 349 



Diploblastic condition, 128, 142, 544, 547 



Diploblastic embryo, 121 



Diplodinium ecaudatum, 85 



Diploid number, 108, 109 



Dipnoi, 344, 346 



Diptera, 287, 288 



Direct response, 54, 469-470 



Disc, basal, 134-136 

 starfish, 191, 192 



Discoidal cleavage, 117, 118, 355, 356, 376, 449 



Discontinuous distribution, 499 



Discontinuous stimulus, 54, 467 



Disease, 289, 421, 487, 488, 537 



Dispersal, animals, 187, 216, 500-501 



Disperse phase, 12 



Dispersion medium, 12 



Dissimilation, 32, 33, 35, 37, 42, 65, 71, 168 



Dissociation, 11 



Distribution, discontinuous, 499 

 geographic, 5, 499-509 

 past, 510-515 



Diurnal rhythms, 482 



Divergence, 446, 543 



Diving beetles, 481 



Diving birds, 401 



Division of labor, 93, 111, 292, 295, 430, 494 



Dogfish, fresh-water, 345 



Dogfish sharks, 338, 347 



Dogs, 58, 413, 474 



Dolichoiilossus kowalevskii, 309 



Dolphins, 417, 446 



Domesticated birds, 405 



Dominance, 295, 475, 530 



Dominant genes, 528, 530-532, 537 



Dormancy, 23, 430 



Dorsal aorta {see Aorta, dorsal) 



Dorsal blood vessel, 231, 232 



Dorsal fins, 346, 348 



Dorsal line, 176 



Dorsal nerve cord, 176 



Dorsal pores, 229 



Dorsal root, 327, 328 



Dorsal vessels, 231, 232, 253 



Double circulation, 361 



Down, 392 



feathers, 392, 393 



Dragon flies, 289, 514 



Dreaming, 474 



Drones, 291, 292, 539 

 Drosophila, 114, 521, 522, 540 

 Dryophantes tanata, gall, 286 

 Duckbill, 411, 412 

 Ducks, 401, 403-405, 500 



beak, 399 



foot, 400 

 Duct, 439 



Ductless glands, 366-367, 464-466 

 Dugong, 417 

 Dujardin, 18, 31, 554 

 Duplicate genes, 535 

 Dura mater, 369 

 Durant, W. J., 550 

 Dwarfness, 537 

 Dyad, 448 

 Dysentery, 87 

 Dytiscus, leg, 274 



Ear, 330-332, 336, 341, 354. 362, 369, 379, 380, 

 383, 394, 395, 409-410, 445, 519 

 muscles, man, 519 



Ears, planarian, 157 



Earthworm, 51, 229-240, 463 



Earwigs, 289 



Ebers, George, 549 



Ecdysis, 258 



(See also Molting) 



Echidna, 411 



Echinococcus granulosus, 169 



Echinodermata, 200, 545, 547 



Echinoderms, 113, 191-207, 437, 438, 441, 442, 

 444, 462, 463, 466, 483 



Echinoidea, 201, 202 



Echinopluteus, 206 



Echiurus pallassii, 247 



Ecology, 5, 477-486 



Economic relations, 69, 80-83, 87-90, 132-133, 

 153, 156, 169-174, 178-182, 198-199, 207, 

 226-228, 237, 248-249, 258-259, 265, 270, 

 281-295, 299, 301-302, 315, 337, 342-343, 

 358, 374, 389, 404-405, 421 



Ectoderm, 119-123, 127, 128, 135-137, 140, 142, 

 155, 184, 193, 307, 418, 419, 449 



Ectoparasites, 497 



Ectoplasm, 63-65, 66, 70, 85 



Ectopterygoid, 386 



Edentata, 411, 415 



Eel, 335 



electric, 505 

 migration, 502 



Eel worm, 175 



Effectors, 163, 238, 239, 327, 468, 470 



Efferent impulse, 163 



Efferent path, 239 



Egestion, 32, 33, 36, 37, 41, 42, 05, 71, 102, 138, 

 161, 168, 177, 196 



Egg cells, 44, 45, 105-107, 109-114, 116-118, 120, 

 121, 132, 135, 140, 149-151, 161, 162, 167, 

 172, 173, 178, 198, 214, 236, 236, 334, 419, 

 448, 493, 528, 630, 532, 537-539, 554 



