4H 



INDEX 



Hymenoptera, eaten by birds, 251, 255 

 — , male genitalia more differentiated 



than female, 153 

 — , mimetic groups not easily explicable 



by selection, 259-60 

 — , mimicry by Diptera, 257-58 

 — , warning colours, 245 

 Hypertely, 325, 330 

 Hyponomeuta, physiological races, 75, 

 121 



Iberus, geographical races, 108 



Immunity, 1 19 



Impulse, internal, 339, 373 



Inbreeding, effects of isolation, 1 70 



Independence, 353 



Individual as lowest taxonomic unit, 



60 

 Individual variants, 8, 82 



, basis of geographical races, 127 



, compared with geographical 



races, 125 



, Darwin's views on, 183 



, difficulty of establishment, 224 



, spread of, 127, 185, 213-15 



, swamping by crossing, 1 85 



Induced modifications, 28-36 

 , circumstantial evidence for in- 

 heritance of, 42 



, experimental precautions in 



proving inheritance of, 32 



, inheritance of, 30, 216, 372 



, summary of data on, 55 



Ingoldby, geographical races in Helio- 



sciurus, 1 14 

 Inheritance, matroclinous, 53 

 — , particulate and blending, evolu- 

 tionary significance, 184 

 Inhibitions, removal of, 340 

 Insects, antennal scrobes, 308 



— , cases as protection against environ- 

 ment, 360 



— , change of habits in, 53 



— , influence of food on size, 79 



— , scent-production, 293 



— , specific differences in genitalia, 297 



Insular forms, 82, 134-39 



Intermediates, 86, 88 



— , due to crossing, 88 



— , mid-, 88 



— , simple, 25 



— , types of, 89 



Introduced species, as evidence that 

 adaptation is not close, 306 



Irreversibility of evolution, 365 



Isolation and inbreeding, 170 



Isolation, analysis of, 141 



— , as an aid to establishment of 

 mutants, 224 



— , geographical or topographical, 129 



Isolation, permanent, 130, 153 

 Isoptera, runways as controllers of en- 

 vironment, 360 



Jackson, wing-development in Sitona, 



.147 

 — , winglessness in beetles, 147 

 Jameson, selective origin of race of 



mice, 201 

 Jeannel, speciation in cave animals, 



148 

 Jenkinson, dependence of one character 



on another in development, 166 

 — , dependence of characters on each 



other decreases with age, 168, 



180 

 Jennings, experiments on pure lines, 



191 

 Jensen, influence of substratum on 



Anomia, 81 

 Johannsen, experiments on pure lines, 



191 

 Jollos, effects of high temperature on 



mutation-rate, 29, 223 

 Jones, experiments on food-habits of 



birds, 247-49 

 Jordan, A., ' elementary species,' 58, 



64 

 Jordan, K., genitalia as a factor 



isolating species, 152 

 — , geographical races as base of new 



species, 154 

 — , geographical races in Ctenophthal- 



mus, 1 1 3 

 — , mimetic ' trends ' in Papilio, 259 

 — , nature of specific characters in 



mimetic Lepidoptera, 262 

 — , seasonal variation in genitalia, 152 

 — , when a variety becomes a species, 



129 

 Jordanon, 59, 64, 73 

 Jourdain, Cuckoo's eggs, 267 



Kallima, protective coloration, 234 



Kammerer, experiments on Alytes, 36 



— , experiments on Ciona, 37 



— , experiments on Salamandra, 38 



— , insular forms of lizards, mammals, 



etc., 139 

 Kane, selection in Camptogramma, 202 

 Karasbergia, characters of, 283 

 Keith, ' momentum,' 340 

 Kellogg, evidence for Natural Selection, 



186 

 — , orthogenesis, 323, 325 

 Kellogg and Bell, experiments o 

 Philosamia, 36 



, variation not reduced in 



sects during season, 20 



