624 



ANIMAL BIOLOGY 



Deer, 439, 534, 535 



foot bones, 436 



Virginia, 537 

 Defective genes, 564 

 Degeneration, 189, 203, 318, 320, 512 

 Delamination, 477 

 Demospongiae, 130 

 Dendrites, 102, 103, 243 

 Dendron, 103 



{See also Dendrites) 

 Dendrostoma alutaceum, 252 

 Dentalium pretiosum, 226 

 Dentine, 324, 425, 427 

 Dentition, 426 

 Dermal bones, 350 

 Dermal gills (see Dermobranchiae) 

 Dermal layer, 132, 464 

 Dermal scales, 374, 424 

 Dermis, 324, 366, 425, 465 

 Dermobranchiae, 196, 200 

 Desert faunas, 510, 512 

 Desmognathus, 371 

 Determination of sex, 566—568 

 Determiners, 555 

 Development, ascaris, 181-182 



butterfly, 286 



fish, 361 



frog, 378, 379, 380 



Gordius, 184-185 



hookworm, 182-183 



locust, 285 



mammal, 444, 446, 447 



mosquito, 292, 293 



reptiles and birds, 382-385 



shrimp, 270, 271 



Trichinella, 183, 184 



tunicate, 317, 318 



(See also Life history) 

 Devil fish, 226, 227 

 Devonian period, 350, 369, 539, 542 

 De Vries, Hugo, 550 

 Dextrose, 21 

 Diabetes, 492 



inheritance, 564 

 Dialysis, 12 

 Dialyzers, 12 

 Diaphragm, 328, 400, 427 

 Diastrophus nebulosus, gall, 291 

 Didelphia, 429 

 Diecious animals, 107, 181, 189, 192, 198, 223, 



229, 248, 269, 275, 321, 339, 471 

 Diencephalon, 334, 343, 346, 376, 399 

 Differentiation, 85, 95, 458-460, 475 

 Difflugia urceolata, 81 

 Diffuse nervous system, 472 

 Diffusion, 11 



Digestion, 33, 35, 488-489 

 Digestive enzymes, 13, 65, 86, 99, 133, 140, 235, 



327, 329, 467, 489 

 Digestive system, 104, 105, 327-329, 466-467, 

 574-575 



annelids, 247 



ascidian, 317 



beetle, 282 



bird, 406, 407 



Digestive system, crayfish, 268 



earthworm, 237 



fishes, 356-357 



honeybee, 281 



leech, 250 



mussel, 214, 216 



planaria, 160 



sea cucumber, 209 



sea urchin, 208 



shark, 345 



spider, 303 



starfish, 198 



vertebrate, 323 



(See also Alimentary Canal) 

 Digitigrade foot, 436 

 Dihybrids, 560-561 

 Dimorphism, 471, 572 

 Dinophilus, 247 

 Dinosaurs, 403, 410, 411, 543 

 Diphtheria, 519 

 Diphycercal tail, 366 



Diploblastic condition, 130, 144, 574-576 

 Diploblastic embryo, 123 

 Diplodinium ecaudatum, 86 

 Diploid number, 110, 111 

 Dipnoi, 350, 352 

 Diptera, 292, 293 

 Direct response, 55, 497-498 

 Disc, basal, 134-136 



starfish, 194, 195 

 Discoidal cleavage, 119, 120, 361, 362, 386, 477 

 Discontinuous distribution, 527 

 Discontinuous stimulus, 55, 495 

 Disease, 294, 484, 515-520, 564 

 Dispersal, animals, 190, 220, 528-529 

 Disperse phase, 13, 22 

 Dispersion medium, 13 



Dissimilation, 33, 34, 36, 38, 43, 65, 71, 170 

 Dissociation, 12 

 Distribution, characteristics in hybrids, 588 



discontinuous, 527 



geographic, 5, 527-537, 549 



marine life, 611 



past, 527, 538-543 

 Diurnal rhythms, 510 

 Divergence, 473-474 

 Diving beetles, 609 

 Diving birds, 414 

 Division of labor, 95, 297, 301, 458-459, 522 



germ cells, 113 

 Dodo, 422 

 Dogfish sharks, 344, 346, 363 



brain, 346 



circulatory system, 346 

 Dogs, 58, 436, 502 

 Dolichoglossus kowalevskii, 316 

 Dolphins, 441, 474 

 Domesticated birds, 423 

 Dominance, 300, 503, 558 



incomplete, 563 

 Dominant genes, 556, 558-560, 564 

 Dormancy, 24, 458 

 Dorsal aorta (see Aorta, dorsal) 

 Dorsal blood vessel, 236, 237 

 Dorsal fins, 362, 354 



