INDEX 



651 



Cysts, 422 



Cytology, definition of, 138 

 Cytolosis, 136 

 Cytoplasm, 416 



definition of, 129 



role of in heredity, 463-464 

 Czechs, 561 



Dandelion, 505 



seed dispersion in, 4^9 

 Daphnia, 413, 500 



Darwin, Charles, 443, 488, 493, 495, 

 508, 513, 516, 518, 519, 522, 523, 

 524, 526, 527, 528, 530, 540, 555, 

 556 

 Darwin, Erasmus, 494 

 Darwin, Leonard, 494, 642 

 Datura, 457 

 da Vinci, Leonardo, 305 

 Death, biological significance of, 610- 



611 

 Deer, 335 



Deficiency, in chromosomes, 457 

 Deletion, in chromosomes, 457 

 Desmospongia, 79 

 Dendrites, 340 

 Dengue, 620 

 Dentalium, 97, 432 

 Denticula, 71 

 Dentine, 286 



Dermo-muscular sacs, 335 

 Dermoptera, 101, 115 

 de Saussure, 241 

 Desmids, 164-165 

 Determinate cleavage, 432 

 Determiners, 450 

 Development, 415 

 Devonian period, 476, 513 

 DeVries, 443, 524, 525 

 Dextrin, 295 

 Diabetes, 296 

 Diaphragm, 318 

 Diatoma, 71 

 Diatomaceae, 71 

 Diatoms, 21, 163-164: 



shells of, 163 



uses of, 163 

 Dicotyledons, 64, 75, 77 



definition of, 240 

 Dick test, 633-634 

 Diencephalon, 346, 348, 397, 400 

 Differentiation of the embryo, 420-421 

 Diffusion, 133-lSA 

 Digestion 



Ameba, 154-155 



extracellular, 281-284 



in higher animals, 282 



Hydra, 182 



insects, 209 



intracellular, 281 



in lower animals, 281-282 



Paramecium, 159 

 Digestive glands, 282 

 Digestive systems (intake devices), 



275 

 Digestive tract 



earthworm, 189 



insect, 209 

 Digitigrade feet, 333 

 Dihybrids, 447, 448 

 Dinornithiformes, 113 

 Dinosaura, 111 



Dinosaurs, 236, 479, 481, 513, 542 

 Dioecious plants, 175 

 Diphyllobothrium latum, 229 

 Diploblastic organisms, 68, 419 

 Diplococcus, 71 

 Diploid number, 429 

 Dipnoi, 107 

 Diptera, 102 

 Discomedusae, 320 

 Discontinuous variations, 572 

 Diseases 



causes of, 611 



death rates from, 613 



degenerative, 612-613 



relations of environment to, 611-612 

 Display of energy, animals, 366 

 Distribution, evolutionary evidence 



from, 508-510 

 Divergence theory, 503 

 Division of labor 



Coelenterata, 179 



Hymenoptera, 214 

 Divisions of plants, 65 

 Division series, 415 

 Diverticula, digestive, 282 

 Dodder, 216 

 Dogs, 329, 515, 552, 639 

 Dolphins, 117 

 Domestic animals, 576 

 Domestication, 550 



of plants and animals, 569-571 

 Dominance, 447-449 

 Dorsal cerebral ganglion, bee, 211 

 Dorsal pores, earthworm, 188 

 Double fertilization, 177-178 

 Dragonflies, 100 

 Drone, 201, 212 



Droplet method of infection, 622 

 Drosophila, 457, 458, 461, 468, 525 

 Dublin, Louis, 612 

 Ductless glands, 391-402 

 Duodenum, 291, 392 

 Duplication, in chromosomes, 457 

 Dura mater, 345 

 Dustbowl, 592 

 Dutch elm disease, 580, 581 



