INDEX 



Egg cell, 122 



Eggs, of snakes, 573 



Ehrenberg, C. G., 229 



Eimeria, 245 



Elaphe rulpinus, 573 



Elastic connective tissue, 52 



Elastic fibers, 61 



Electro pilosa, 361 



Electric organ, of torpedo ray, 557 



Electrolytic solution, 23 



Elephant, 580; origin and evolution, 628, 629; 



reproductive potential, 609 

 Elephas, 629 

 Eleutherozoa, 216, 486 

 Elytrae, of beetles, 464 

 Embrvo, 132, metabolic requirements of, 159- 



165' 

 Embryology, 8 

 Embryonic cells, 159 

 Embryonic membranes, 159; of egg-laving 



vertebrates, 162; of mammals, 162 

 Embryonic theca, of Hydra, 299 

 Embrvos, of mammals and reptiles, 589 

 Emu, '574, 578 

 End feet, 99 



Endocrine glands, 95, 117 

 Endocrine mechanisms, of invertebrates, 525 

 Endocrine organs, of vertebrates, 522 

 Endocrine system, 87, 95 

 Endocrines,'95, 117-124 

 Endoderm, 151, 152, 154 

 Endomixis, in Paramecium, 254, 256 

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

 mecium, 250 

 Endoplasmic reticulum, 19, 44 

 Endopodite, 427, 428 

 Endoskeleton, 91, 527; of early fishes, 557; of 



echinoderms, 529; of echinoids, 499, 501; of 



squid, 528; of starfish, 496; of vertebrates, 



538 

 Endothelium, 52 



Endothermy, in birds and mammals, 598 

 Energy, 26,' 28, 29, 30, 35, 37, 111; transfer 



of, in food chains, 607 

 Ensu, 379, 380 

 Entamoeba histolytica, 237-239 

 Enterocoela, 219, 221, 368 

 Enterocoelous coelom, 543 

 Enteron, of Platyhelminthes, 512 

 Entomostraca, 424, 436, 437 

 Entoprocta, 216, 221, 344, 356, 357; proto- 



nephridia of, 519, 520 

 Entrance cone, 144 

 Environment, 594; as selective agent, 650; 



effect on development, 159, 195-196, 199 

 Enzymes, 28, 30, 35, 44; digestive, 70 

 Eocene Period, and rise of elephants, 628 

 Eohippm, see Hyracolherium 

 Eolis coronata, 385 

 Ephelota, 259 



Ephyra, 305 



Epiboly, 152 



Epidermal scales, of reptiles, 565 



Epidermis, 31, 60, 154, 167; of coelenterates, 

 284; of Hydra, 287; of nematodes, 350; of 

 planarians, 322; of rotifers, 346 



Epididymis, 129 



Epimere, 155 



Epmephelus, 560 



Epinephrine, 113, 115, 121 



Epiphanes senta, 345, 348; life cycle, 346 



Epipodite, of lobster, 427; of trilobite, 423 



Epistylis, 258 



Epithelial tissue, 59-61 



Epitheliomuscular cells, of Hydra, 288, 291 



Equational division, 137, 139 



Equatorial plate, 41, 136 



Equilibration, 102 



Equilibrium, 108; conditions of destruction by 

 man, 615; in living systems, 654; in pond 

 communitv, 61 1 



Equus, 625; E. burchelii bolmu, 588; E. scotti, 

 627 



Errantia, 401 



Eryops, 561 



Erythrocytes, 63, 84, 164, 199 



Esophagus, 48, 60 



Estivation, 598 



Estrogen, 123 



Eucestoda, 333-340 



Euciliata, 257 



Eucoelomata, 219, 221, 222 



Eudorina, Idl 



Eugenics, 200 



Eiio/ena, 239-243; E. gracilis, 242; E. viridis, 

 240, 241, 242 



Euglenoid movement, 239, 240 



Eumetazoa, 219, 221, 222 



Euplectella, 273 



Euplotes, 258 



Europe, early man in, 642; elephants of, 630; 

 wild horses of, 625 



Eurypterida, 216, 423, 480 



Euryplerus, 423 



Eustachian tube, 48 



Eusthenopteron, 559 



Eutheria, 579, 585 



Evolution, 616; evidence for, 619-637; non- 

 random, 653; of elephants, trends in, 630; 

 of horses, trends in, 627; of maii, 637-646 



Excitation, 99 



Excreta, 82 



Excretion, 56, 82-84; in Amoeba, 234-235; in 

 aquatic and terrestMal arthropods, 485; in 

 coelenterates, 518; in crayfish, 432; in cten- 

 ophores, 518; in earthworm, 408; in Hydra, 

 293; in locust, 449-450; in nematodes, 351; 

 in Nereis, 400; in Paramecium, 253; in pla- 

 narians, 317; in Porifera, 518; in Protozoa, 

 518 



688 



