486 



INDEX 



diffusion of gases, 8. 

 digestion, in Amoeba, 16. 

 digestive cavity, of Hydra, 115. 

 ,, ,, Medusa, 120. 



Obelia, 119. 

 digits, reduction, 239 241. 

 dihybridism, 201-203, Figs. 80, 81. 

 dimorphic flowers, 356. 

 dimorphism of gametes, 139. 

 Dinosauria, 297. 

 Dinotherium, 314, Pig. 160, 

 dioecious, 99, 105. 

 Diplodocus, 299. 

 Diplosoma cryatallinum, larva, Fig. 



130. 



Dipnoi, 255, 291. 

 Diptera, p?edogenesis, 199. 

 direct nuclear division, 80, Fig. 36. 

 discontinuity between species, 222, 



Fig. 85. 

 in distribution, 319, 320, 



333. 

 in evolutionary series, 



Lamarck on, 376. 

 in organic world, 221. 



discontinuous variation, 149, 153 



156. 



Dismorphia praxinoe, 345, Fig. 176. 

 dispersal of organisms, 320327. 

 distribution, geographical, 319 333. 

 disuse (see use and disuse). 



of wings, effects of, 397, 398. 

 divergence in evolution, 213. 



A. E. Wallace on, 390. 

 ,, Charles Darwin on, 387. 

 division of labour, 39, 43, 44, 60, 85, 



119. 

 ,, ,,- between male and 



female, 127. 

 dodder, 402, 403, Fig. 184. 



, , vestigial leaves, 262, Fig. 184. 

 dodo, 258, 397. 

 dog, skull and dentition, 251 253, 



Figs. 107, 108. 

 vestigial teeth, 260. 

 dogfish, embryo, 270, Fig. 120. 

 dolphin, Figs. 161, 162. 

 dolphins, convergence in, 248. 

 ,, shark-toothed, 318. 

 domestication, Charles Darwin on, 



410. 



,, Lamarck on, 378. 



dominant characters, 197, 207. 

 Draba verna, elementary species in, 



224, 412. 



drone flies, mimicking bees, 343. 

 mistaken for bees, 215. 



Dubois, E., 423. 



Dujardin, 38. 



dynamics of cell-division, 74. 



E. 



ECHIDNA, 234, 301, Fig. 92. 

 echinoids, larval stage, 276. 

 Echinus, blastpmeres, 45. 



,, hybridization in, 174. 

 ectoderm, 47. 



of coelomates, 124. 



Hydra, 115, 116, 118. 

 edentates, 301, 333. 

 education, 426. 

 eels, dispersal of, 325, 326. 

 egg cell (see ovum). 

 ,, of Ascaris, mitosis, 79, Fig. 35. 

 bird, 140, Fig. 70. 

 frog, 268. 

 eggs, dispersal of fish, 322. 



similarity in different or- 

 ganisms, 162. 

 ,, size, 267. 

 Eigenmanu, 183. 

 Elasmobranchii, 291. 

 electrical energy, transmission, 189. 

 electric eel, 256. 



,, organs, 256. 

 electro-magnetic theory of mitosis, 



74, 75. 



elementary species, 224, 412. 

 elephants, ancestry, 312 314, Fi. 



159. 



limbs, 239. 

 Elephas, 314. 

 elite, 411. 



Elodea, evolution of oxygen, 31. 

 embryo, fixation, 126. 



of chick, 265, Figs. 117, 122. 

 Fucus, 101, Fig. 47. 

 ,, mammals, 270. 



,, rabbit, 265, Fig. 117. 

 embryology, Erasmus Darwin on, 



371, 372. 

 evidence afforded by, 



261281. 

 embryonic cell, 48. 

 embryo-sac, 48, 106, 107, 108. 

 embryos of birds and reptiles, 270. 

 Emily Henderson, sweet pea, 208. 

 Empedocles, 369. 

 Encrinites, 274. 

 endoderm, 47. 



of coelomates, 124. 

 of Hydra, 115, 116, 118. 

 endoplasm, 14, 22. 

 endosarc, 14. 



