J.\DEX. 



221 



Development, embryonic and post- 

 embryonic, 192 



Differentiation, histological, 116; 

 histological and organological, 

 igi; nature of histological, 85 



Digestive tract, the, 124; the divi- 

 sions and appendages of, 126; 

 relative length in herbivores and 

 carnivores, 128 



Diphycercal tail, 48 



Diplozoon paradoxum, 199 



Diporpa, 199 



Direct development, 193 



Direct nuclear division, 84 



" Directive corpuscles," 177 



Distoma, 174 



Distribution, 210; factors in, 211; 

 the six primary regions of, 213 



Distribution of animals, 49; proofs 

 of phylogend from, 50 



Division, direct nuclear, 84, 168 



Domestication, 52 



"Dorsal," 163 



Ductus ejaculatorius, 144 



Dujardin, 21 



Earth-worm (angle-worm), sexual 

 organs of, 141; hermaphrodit- 

 ism of, 141 



Echinoderma, 22 



Ectoblast, 187, 197; organs formed 

 from, 192 



Ectoderm, 188 



Ectodermal gut-areas, 126, 127 



Ectoparasites, 204 



Egg, the, 95; of the bird, 73; -cell, 

 96; of echinoderm (S. lividus), 

 96; -nucleus, the, 177; of the 

 cephalopod, 186; of the insect, 

 186; of Nassa mutabilis, 185; of 

 Petromyzon, 185; alecithal, 185; 

 centrolecithal, 183, 186; diagram- 

 matic section of the hen's, 184; 

 holoblastic, 185; meroblastic, 

 185; telolecithal, 183 



Eggs, " summer," 174; "winter," 



174 



Eichhorn, 15 

 Elastin, 102 

 Embryo defined, 193 

 Embryology, 4, 165, 193 

 Embryonic development, 192 

 Endolymph, 151 

 Enteropneusta, 129, 131 

 Entoblast, 187, 197; organs formed 



from, 192 

 Entoderm, iSS 

 Entoparasites, 204 

 Environment, influence of, 64 



Eohippos, 40 



Epiblast, 188, 397 



Epigenesis, 19 



Epithelia, 117; glandular sensory 



E., 88; many-layered E., 90; 



sensory E., 89 

 Epithelial tissues, morphology of, 



87 



Epithelium, 98; ciliated E., 89; 

 contrasted with connective tis- 

 sue, 99; columnar, 89; covering 

 E., 89; cuboidal or pavement E., 

 89; flagellated E., 89; flat E., 89; 

 functionof, 87; germinal E., 140; 

 glandular E., 92; one-layered E., 

 89; sensory E.,g8, 99; sexual or 

 germinal, 94, 95 



Equatorial plate, 82 



Evolutio, 19 



Evolution in breeding, factors of, 

 53; vs. creation, 27; state of the 

 question in 1830, 27; vs. epigene- 

 sis, 19; in nature, factors of, 53; 

 original meaning of, 19 



Excreta, 88, 123 



Excretion, nature of , 138 



Eye, 153; section of human, 155; 

 of the vertebrates, 155; phylog- 

 eny of, 66; refractive bodies in, 



154 

 Eyes, various types of, 156 



Fabricius ab Aquapendente, 14 



Factors of evolution in breeding, 

 53; in nature, 53 



Faeces, 123 



Fecundation, artificial, 177 



Fertility of hybrids and mongrels, 

 the, 34 



Fertility in sexual reproduction, 

 conditions governing, 35 



Fertilization, 177, 178, 196; artifi- 

 cial, 178; essential feature of, 

 179. 197; P ar t played by the two 

 nuclei in, 180 



Flagella, 90, 145 



Flimmerlappchen, 140 



Food-yolk, 97 



Fore-gut, 126 



Fossils, 39; old ideas regarding, 



24 



Functions, community of, 200 

 Funnel, the ciliated, 140 



Galen, 14 



Galenus, Claudius (Galen), 13 



Ganglion-cells, 113 ; apolar, 114 ; 



bipolar, 113 ; multipolar, 114 ; 



unipolar, 114 



