INDEX 



465 



Dichogamy, i. 94 ; Delpino on, ii. 257 ; 

 ignorance of botanists of, prior to pub- 

 lication of Fertilisation of Orchids^ 

 ii. 254 



Dick, Sir T. Lauder, Survey of Glen 

 Roy by, ii. 175 



Dickens, quotation from, ii. 446 



Dickson, Dr., ii. 56 



Dickson, W. K., i. 6 



Dicotyledons, Heer on oldest known, 

 ii. 239 ; sudden appearance, ii. 239 



DidelphyS) i. 86 



Digestion, beneficial effect on plants, 

 ii. 407 



Dillwyn, paper in Gardeners' Chronicle, 

 ii. 248 



Diluvium, tails of, ii. 149 



Dimorphism, in Cynips, i. 249, 250 ; 

 Darwin on, i. 222, 224, 229, 267, 274, 

 298 ; difficult to explain, i. 356 ; and 

 mimicry, i. 265 ; in parasitic plants, 

 i. 262 ; Wallace on, i. 265 ; Walsh 

 on, i. 259 ; W T eismann on Sexual, i. 

 356 ; in Cicadas, ii. 90 ; flowers 

 illustrating, ii. 280, 282, 299, 347-52; 

 Darwin knows no case in very 

 irregular flowers, ii. 351 ; in Melasto- 

 macere, ii. 292, 293 ; in Limtm, ii. 

 320 ; in eight Natural Orders, ii. 

 282 ; in Primula, ii. 320, 321, 323, 

 327, 328 ; apparent cases due to mere 

 variability, ii. 384 ; explanation of, 



ii. 373 



Dingo, i. 167 



Diodia, ii. 272 



Diceciousness, origin of, ii. 416 



DioiKza, experiments on, i. 349 ; ii. 

 381, 384, 401, 403 ; response to 

 stimuli, ii. 51, 394, 395; Curtis' ob- 

 servations on, ii. 384 



Dipsaciis, F. Darwin on, i. 369 



Dipterocarpus, survival during glacial 

 period, i. 473 



Direct action, i. 181, 212. 213. 235, 389 ; 

 ii. 235 ; arguments against, i. 222, 

 306 ; Darwin led to believe more in, 

 i. 214; Darwin's desire not to under- 

 estimate, i. 198 ; Darwin's under- 

 estimates, i. 235, 300; facts proving, 

 i- SS^, 389 ; Falconer on, i. 207 ; 

 and hybridity, i. 319 ; importance of. 

 i. 391-2; of pollen, i. 286; variation 

 and. i. 300 



Direction, sense of, in animals, i. 385 



Disease, Dobell on Germs and Vestiges 

 of, i. 235 



Dispersal (see also Distribution), of 

 seeds, i. 40, 416-19, 436, 440, 444, 

 445 ; of shells, i. 52 



Distribution, Forbes on. i. 52, 53, 95, 



VOL. II. 



461 ; Hooker on Arctic plants, i. 

 155; of land and sea in former 

 times, i. 374, 375 ; of plants, i. 51-4, 

 436 ; factors governing, i. 380 ; of 

 shells, i. 96 ; Thiselton-Dyer on 

 plant-, ii. 418, 419 ; Wallace on, 

 i. 118; ii. 17-20; Blytt's work on, 

 ii. n, 17 



Disuse, Darwin on, i. 352 ; effect of, i. 

 87 ; Owen on, i. 203 



Divergence, Hooker on, i. 134 ; prin- 

 ciple of, i. 99, 101, IOQ, 153, 199 



Diversification, Darwin's doctrine of 

 the good of, i. 199 



Dobell, H., letter to, i. 234-5 



Dogs, i. 127, 128, 138, 167, 168 ; descent 

 of, i. 387 ; experiment in painting, ii. 

 72 ; Expression, ii. 101 ; habits, ii. 102; 

 rudimentary tail inherited in certain 

 sheep-, ii. 382 



Dohrn, Dr., visits Darwin, i. 323 ; 

 serves in Franco-Prussian war, ii. 92 ; 

 extract from letter to, ii. 444 



Dolomit Riffe, Darwin on Mojsisovics', 

 i. 374 ; ii. 197 



Domestic animals, crossing in, i. 232 ; 

 Darwin's work on, i. 493 ; ii. 37 ; 

 Settegast on, i. 324 ; variability of, 

 i. 137, 182, 191 ; treatment in Varia- 

 tion of Animals and Plants, i. 168 



Domestication, effects of, i. 131, 134, 

 137, 192, 232; and loss of sterility, 

 i. 274 



Domeyko, on Chili, ii. 144 



Dominant forms, i. 165, 207 



Don, D., on variation, i. 102 ; men- 

 tioned, i. 403 



Donders, F. C., on action of eyelids, ii. 

 100 ; letters to, 100, 101, 104, 105, 

 1 08, 109 



Dorkings, power of flight, ii. 54 



Down, description of house and coun- 

 try, i. 31-6; Darwin's satisfaction 

 with his house, ii. 244 ; instances of 

 vitality of seeds recorded from, ii. 

 245 ; method of determining plants 

 at, ii. 330 ; Darwin on geology of, 

 ii. 165 ; observations on regular lines 

 of flight of bees at. ii. 97 



Down (lanugo), on human body, ii. 39 



Dropmore, i. 66 



Drosera, F. Darwin's experiments, i. 

 369 ; " a disguised animal,' 5 ii. 267 ; 

 Darwin's observations on, ii. 266, 267, 

 284, 289, 320, 381, 384, 385. 395, 396, 

 401, 406-8 ; Darwin's pleasure on 

 proving digestion in, ii. 398 ; effect of 

 inorganic substance on, ii..4O2; experi- 

 ments on absorption of poison, ii. 

 290; Pfeffer on, ii. 400; J. Scott's 



30 



