INDEX 



Digestive glands, 47; in invertebrates, 513 



Digestive juice, 71, 72 



Digestive system, adaptations in, 512; of ani- 

 mals, 511; of Arbaria, 499; of Branchwsluma, 

 551; of crayfish, 430; of invertebrates, 511 

 513; of locust, 448; of Pterobranchia, 543; 

 of Saccoglossus, 542; of starfish, 491; of 

 Thyone, 504; of vertebrates, 47-50, 154; 

 regional specialization, 512 



Digestive tract, 47, 60, 90; of brachiopods, 

 364; of Bugula, 358, 360; of earthworm, 

 405; of ectoprocts, 358, 359; of entoprocts, 

 356, 357; of leeches, 419, 420; of nema- 

 todes, 349, 350; of Nereis, 399; of pelecy- 

 pods, 373; of rotifers, 345, 346; of squid, 

 389 



Digger wasps,, 470, 471 



Dihvbridization, 180, 189, 190 



Dihybrids, 180 



Dileplus, 257 



Dimorphism, in Ohelia, 302 



Dinoflagellates, 243 



Dinosaurs, 566, 569, 575, 577; footprints of 

 621, 622 



Dipeptidase, 72 



Dipeptide, 27 



Diphosphopyridine nucleotide, 33, 36 



Diphyllohothrium latum, 339 



Dipleurula, 219, 509, 543 



Ihplodimum, 258 



Diplograpliis, 540, 544 



Diploid number, 41, 143 



Diplopoda, 216, 423, 478, 479 



Diploverlebron, 561 



Dipnoi, 557 



Diplera, 474, 475; economic and medical 

 importance of, 476; ovoviviparous repro- 

 duction in, 534; wings of, 457 



Disaccharidases, 72 



Disaccharides, 26 



Discharge, 68. 113-114 



Diseases, infectious, causation and spread of, 

 260-262 



Disjunctional division, 136, 139, 185 



Dissociated cells, 158, 167 



Distribution, geographic, 619, 631; geologic, 

 619; of animals, en\ironmental limits to, 

 611 



DNA, see Desoxyribonucleic acid 



Doctrine of Cataclvsms, 648 



Dogs, 580 



ihliolum, 550 



Dolphin, 580 



Domestication, of animals and plants, 636 



Dominant character, 175, 177 



Dormancv, 596; in insects, 456 



Dorsal mesoderm, 155 



Dorsal pores, of earthworm, 405 



Dorsal root, 98 



Dorsal root ganglion, 98 



DPN, see Dij)hosph()p\ ridinc nui Icoiidc 



Dragonflv, 459, 460 



Dromedar\, 631 



DrosophUa, 182; chroinosome maps of, 191; 



chromosomes of, 42, 194, 195; inheritance 



in, 183, 184, 188, 189, 192, 193, 203, 204; 



temperature and development of, 595, 597 

 Duckbill, 131, 630; oviparous reproduction in, 



566 

 Ductless glands, 95 

 Ducts, of glands, 61 

 Ductus deferens, 129; of cravfish, 435; of 



earthworm, 405, 411; of leech, 420; of 



locust, 452; of planarian, 320; see also Vas 



deferens 

 Ductus efferens, 129; of earthworm, 411; of 



planarian, 320; see also Vas efferens 

 Dugesia dorolocephala, 317; D. lignna, 315, 317 

 Dugong, 488 

 Dumas, 141 



Duodenum, 50, 72, 117 

 Dura mater, 89 

 Dvad, 136, 139 



Ear, 90, 91, 101, 108 



Eardrum, 108 



Earth, probable age of, 618 



Earthworm, 402-416; circulatorv svstem, 513; 

 gas exchange, 516; Monocyslis in, 244, 245; 

 nephridia, 519; nervous system, 523; water 

 relations, 602 



Echidna, 579, 581 



Echinarachnius parma, 501, 502 



Echmorocciis granulosus, 333, 338 



Echinodermata, 216, 219, 221, 224, 368, 486- 

 509; relationship to hemichords, 543 



Echinoderms, circulatorv mechanism, 516; gas 

 exchange, 516; endoskeleton, 529; excretory 

 mechanisms, 521 



Echinoidea, 216, 486, 499-503 



Echinopluteus larva, 501 



Echiuroidea, 216, 219, 221 



Ecology, 8, 594 



Ectpderm, 151, 152, 166; neural. 154; super- 

 ficial, 154 



Ectoplasm, 19; of Amoeba, 228, 230; of Para- 

 mecium, 249 



Ectoprocta, 216, 221, 344, 357 361, 362; 

 exoskeleton of, 528 



Ectothermous animals, 596 



Edentata, 580 



Eels, migration of, 602 



Effectors, 98, 100; in coelenterates, 522; in 

 sponges. 423, 522 



Efferent neuron, 98, 100 



Egestion, in Amoeba, 234; in Hydra, 293; in 

 invertebrates, 513 



Egg, 131 



Egg albumin, 27 



Egg axis, 131, 148 



687 



