418 



INDEX 



Natural Selection, final verdict, 371-72 



, general summary on, 309 



, hypothesis or law ? 186 



, indirect evidence, 230 and foil. 



, indirect evidence, classification, 



232 

 , influence of frequency of muta- 

 tions on, 6 

 , in relation to colonial divergence, 



126 



, McAtee's observations, 249-51 



, mathematical treatment of the 



theory, 218-30 

 , mathematical treatment of the 



theory, assumptions, 220 

 , Morton Jones's observations, 



247-49 

 , recent developments of theory, 



184-88 



■, relation to adaptation, 348 



, relation to nature of variation, 



2 1 6-30 

 — — , relation to organisation, 366 

 , relation to specialisation, 350, 



35 !> 3 66 

 , requirements for proof of theory, 



193 



, value of experiments in standard 



conditions, 366 

 Nestor, change of habits, 54 

 Neumayr, on Formenreihe, 58 

 Nicholson, A. J., magnitude of steps 



in evolution of mimicry, 255 

 — , role of parallel evolution in mimicry, 



257 

 Nicholson, E. M., age of heronries, 



105 



Noble, Kammerer's experiments on 



Alytes, 36 

 Nonagria, adaptive specific characters, 



291 

 Non-disjunction, produced by X-rays, 



23 



Norman, albinism in flatfish, 92 



— , male genitalia in Anableps, 151 



— , on Scapanorrhynchus, 131 



— , polymorphism in Epinephelus, 101 



— , xanthochroism in fishes, 93 



Notonecta, intermediacy, 88 



— , local intermediacy of species, 158 



Nuttall, characters of ticks, 286 



— , races of lice, 75 



Octopus, habits of, 54 



Oecanthus, habit-differences, 120, 146, 



150 

 Oligolectic bees, 349, 352 

 Omer Cooper, geographical races in 



water beetles, 2 1 2 

 Opalinidae, determinate variation, 325 



Opisthophthalmus, see Scorpions, adap- 

 tive differences 



Oporabia, selective elimination, 199 



Optimum conditions, 357-60 



— population density, 359 



Orchestia, races with different breeding 

 seasons, 145 



Organisation, 308 



— , in development, 362 



— , internal, 360 



— , not explicable by Natural Selection, 



373 

 — , relation to specialisation, 364-66, 



370 

 Organismal adaptation, 352-53 

 Organs, complex, 306 and foil. 

 Ornithodorus, characters of, 286-87 

 Orthetrum, see Dragonflies 

 Orthogenesis, 323.-43>.373 

 Orthoptera, physiological races, 74 

 Orthoselection, 324 

 Oryctolagus, see Rabbit 

 Osborn, on horns of Titanotheres, 331 

 — , orthogenesis, 324 

 Osgood, species intergradation in 



Peromyscus, 90 

 Ostrich, callosities of, 43 

 Otala, adaptive differences in, 285 

 —j local races, 108 

 Ovarian transplants, 31 

 Oviposition, racial differences in, 120 

 Oxycarenus, death-rates in nature, 194 



Pachygnatha, grasping organs, 294 



Palmeria, young taught what to eat by 

 parents, 254 



Paludestrina, non-heritable variant, 20 



— , spread, 322 



Pantin, four types of respiratory pig- 

 ment, 7 



Papilio, differentiation of genitalia, 152 

 and footnote 



— , mimetic ' trends,' 259 



— , mimicry, 252 



— , nature of specific characters, 262 



— , recombination, 25 



Parabuthus, characters of, 283 



Paraferreola, habits, 278 



Parallel evolution, 257-58 



Paramixogaster, mimicry of wasps, 257 



Paramoecium, Dauermodifikationen, 35 



Parasites, temperature relation with 

 hosts, 359 



Parshley, geographical races of Lygaeus, 

 1 12 



Parthenogenesis, developed locally in 

 Hymenoptera, 124 



Partula, change in population, 215 



— , distribution cf races, 82 



— , races of, 70, 108 



