572 



INDEX 



299; circulatory system of, 293; 

 digestive system of, 292; excretory 

 system of, 295; external features 

 of, 283, 284; general activities of, 

 285, 286; internal organization of, 

 284, 288, 289, 290, 293; irritability 

 and behavior of, 301; metabolism 

 of, 301; nervous system of, 297, 

 298 ; reproduction and life cycle of, 

 305; reproductive system of, 295, 

 296. 



Echidna, 433. 



Echinodermata, 246; classification of, 

 238, 240, 241. 



Echinoidea, 241. 



Ecology, 3, 5, 6, 9, 35; see also Food 

 relations in organisms. 



Ectoderm, of chick, 427, 429; of 

 ccelenterates, 281; of earthworm, 

 308,309; of frog, 408, 409, 417; of 

 Hydra, 249, 251. 



Ectoplasm or ectosarc, 156, 166, 

 178. 



Effector, 108, 269, 299, 317; inde- 

 pendent, 254, 267, 270, 316, 317. 



Egestion, 85, 161, 184, 260. 



Egg-laying in earthworm, 305, 307; 

 in locust, 367, 369; in turtle, 422. 



Egg-laying mammals, 29, 433. 



Eggs, of vertebrates, 402, 424, 428; 

 see also Ovum. 



Eimer, 562. 



Ejaculatory duct, of locust, 358. 



Elasmobranchii, 10, 37. 



Elephant, evolution of, 516, 518. 



Embryo, of frog, 410, 414; of locust, 

 370; of man, 434. 



Embryology, 2, 4, 6, 503. 



Embryonic membranes, 430. 



Embryonic vestiges, 531. 



Emotions, 113. 



Encystment in protozoa, 163, 164, 

 172, 173, 184. 



Endocrines, 97; coordinating effects 

 of, 97, 106. 



Endocrine system, 98, 102. 



Endoderm of chick, 427, 429; of 

 ccelenterates, 281; of earthworm. 



308,309; of frog, 408, 409, 417; of 

 Hydra, 249, 251, 259. 



Endomixis, 184, 188, 214. 



Endoplasm or endosarc, 156, 167, 178. 



Endopodite, 326. 



Endoskeleton, 41, 42; see also 

 Skeleton. 



EndotheUum, 140. 



Enothera, 558. 



Enterocoela, 239, 240, 245, 282. 



Enterocoelous-diploblastic organiza- 

 tion, 246. 



Enterocoelous-triploblastic organiza- 

 tion, 246. 



Enterokinase, 85. 



Enteron, in classification, 238, 240, 

 282; of ccelenterates, 281; of frog, 

 409; of Hydra, 249, 261; in or- 

 ganization of animals, 245. 



Enterozoa, 239, 240. 



Entomostraca, 332, 334, 335. 



Environment, 5; in development, 

 439, 440, 445, 446; of vertebrates, 

 27. 



Enzymes, 74, 76; see also Digestive 

 enzymes. 



Eoanthropus dawsoni, 533. 



Eohippus, 513, 516. 



Ephemerida, 373, 377, 378. 



Epidermis, 290, 300, 302, 417. 



Epigenesis, 418, 436. 



Epipodite, 327. 



Epishjlis, 190. 



Epithelial tissue, 140, 141; columnar 

 epithelium, 140; squamous epi- 

 thelium, 140. 



Epithelio-muscular cells, of Hydra, 

 251. 



Equatorial plate, 139. 



Erepsin, 85. 



Errantia, 313. 



Eryops, 13. 



Erythrocytes, 103, 145, 146. 



Esophagus, 47, 290, 292, 354. 



Eudorina, 199, 215, 216. 



Eugenics, 488. 



Euglena, behavior of, 169; metabol- 

 ism of, 170; movements and loco- 



