INDEX 



449 



Discontinuous variation, 267 



Dispersal, of nuinimals, 160; aids to, 

 258; barriers to, 257 



Distribution, f^eographical, see Geo- 

 graphical distribution. 



Disuse, see Use and disuse 



Divergence, 27 



Division of labor, 23 



Dogs, ancestry of, 271 



Dominance, 280 



Dordogne, 207 



Draco volans, 230 



Drosophila, -419, 428; chromosomes 

 of, £91; mutation and normal eye. 

 269; and Mendelian inheritance, 

 287; multiple allelomorphs, 314; 

 linkage and crossing over, 30?, 308; 

 multiple crossing over, 309; sex- 

 linkage, 312, 313, 315; non-dis- 

 junction, 300; reverse mutations, 

 402; chromosome maps, 311; and 

 pure lines, 356 



Drosophila melanogaster, see Droso- 

 phila. 



Dryopithccus fontani, 198 



Dubois, Eugen, 198 



Duck mole, shoulder girdle of, 80 



Dugdale, 308 



Earthworm, 36 



Echidna, claw of, S5 



Echinodermata, 28, 132 



Ectoderm, //>, 41 



Edwards, Jonathan, 370 



Ehrlich, 95 



Elasmosaurus, 153 



Electrical organs, 237 



Elephants, Indian, 165; African, 165 

 foot, 166; skull, 167; tooth, 16S 

 size of, 166; limbs, 166; trunk, 166 

 tusks, 167; teeth, 168; Columbian, 

 398, 399; evolution of head and 

 teeth, 174; phylogeny of, 169 



Elephas, 172; antiquus, 173; columbi, 

 173, 399; imperaior, 173; meridio- 

 nalis, 173; primigenius, 126, 173 



Embryology, 39 



Embryos, 52, 53 



Empedocles, 5, 6 



Endocrine glands, 94 



Endoderm, 40, 41 



English sparrow, 251 



Enteron, 40 



Entheus peleus, 22 



Environment, 2, 211; modification of, 

 248; availability of, 252; response 

 to, 251; continuity of, in evolution, 

 436; duration of, 437; of fossils, 

 127; effects on soma and germ 

 plasm, 419; and existence, 430, 431; 

 and sex determination, 338; and 

 eugenics, 383; and human life, 

 372 



Eoanthroputi dawsoni, 202; phylogeny, 

 204; skull, 203 



Eocene, 122; elephants, 168; horses, 

 176, 178, 179; camels, 185 



Eohippus, 176, 178, 183; feet and 

 teeth, 179 



Ephemera varia., 138 



Epihippus, 179, 183 



Equation division, 294 



Eqims, 182, 183 



Eryops, 151 



Estabrook, 368 



Ethiopian, 255, 256 



Eubleptus daniehi, I4O 



Eugenics, 374; goal of, 375; limita- 

 tions, 377; and environment, 383; 

 practical aspects, 383 



Eugenics Record Office, 359 



Euglena, 93 



Eutheria, 103, 159 



Evidence, for evolution, 105, 119; for 

 inheritance of acquired characters, 

 417, 419 



Evolution, 3, 4; history of, 5; emer- 

 gent, 442; purposive, 17; experi- 

 mental, 440; nature of progress in, 

 435; latitude of heritage in, 435; 

 and environment, 436, 440; of Mol- 

 lusca, 132; of Arthropoda, 134, 137; 

 of insects, 142; of vertebrates, 144; 

 of elephants, 164, 174; of horses, 

 175, 183; of camels, 185; of man 

 187 



Evolutionists, 9 



Excretory system, 65; in chick em- 

 bryos, 65 



Existence, factors in, 430 



Exoskeleton, 82 



Eye, development of, 49, 50; evolu- 

 tion of, 395; of primitive insect, 

 396; of squid, 112; of vertebrate, 

 113; loss in burrowing animals, 224 



Eyelid, third, 88 



