INDEX 



425 



Wagner, rivers as barriers to species, 134 

 Walker, colour-polymorphism, 282 

 Ward, bats roosting according to their 



species, 148 

 Warning colours, 232 



, associated with gregarious larvae, 



247 



, evolution of, 245-46 



, in Lepidoptera, 246-47 



, in Pentatomidae, 244 



— — , McAtee's observations, 249-51 



, Morton Jones's observations, 



247-49 



, not developed in some noxious 



forms, 244 



, sometimes really blending, 243 



Warren, B. C. S., genitalia of the Hes- 



periidae, 155 

 — , local forms of Hesperiidae, 173 

 Warren, E., correlation in Portunus, 163 

 Waterhouse, specific intergradation in 



Tisiphone, 89 

 Waters, influence of diet on colour of 



Coleophora, 79 

 — , local form of Euxanthis, 1 72 

 Weber, optimum conditions for Tri- 



aleurodes, 358 

 Webster, temperature-relation between 



Toxoptera and Lysiphlebus, 359 

 Weldon, Natural Selection in Car- 



cinus, 197 

 — , observations on Clausilia, 211 

 Wesenberg-Lund, origin of changes in 



Daphnia, 215 

 Whedon, characters of Lestes, 291 

 Wheeler, co-adaptation, 308-9 

 — , ' larval memory,' 51 

 — , subspecies, 67 

 — , temperature of ants' nests, 360 

 Whitman, determinate evolution, 325 

 Wild type, 26, 228 

 Willey, growth-rate of Copepods in 



north and south, 123 

 — , protective resemblance, 233 



Willis, ' age and area,' 82 

 Winglessness, 147 

 — , effect on dispersal, 147 

 Winterstein, variation in function, 5 

 Wladimirsky, experiments on Plutella, 39 

 Woltereck, change in population of 



Daphnia, 215 

 — , experiments on Daphnia, 39 

 — , non-heritable characters, 70 

 — , seasonal variation in Daphnia, 12 

 — , variation, 2 

 — , variation in Daphnia, 21 

 Wood Jones, ' habitat ' forms of corals, 



81 

 Woodger, antithesis between structure 



and function, 300 

 — , hypothesis and ' laws,' 186 

 — , methodology of evolutionary study, 



16-17 

 — , nature of development, 1 79 

 Woodruffe-Peacock, selection of colour 



forms of Cepea, 200 

 Woodward, antlers of Irish Elk, 331 

 Wright, evolution of dominance, 227 

 — , mathematical treatment of Natural 



Selection, 218 

 - — , random elimination, 222 

 — , viability of mutants, 223 



Xanthochroism, in fish, 93 

 X-rays, effect on mutation-rate, 29 



Zaphrentis, lineages, 66 



Zeleny and Mattoon, experiments on 



pure lines, 191 

 Zimmermann, ' trend ' in Polistes, 50 

 Zjoarces, adaptive characters, 287 

 — , hereditary stability of races, 70 

 — , races of, 69, 144 

 — , variation of, contrasted with that 



of eel, 105 

 Zygaena, mating between races, 150 



Printed in England at The Ballantyne Press 



Spottiswoode, Ballantyne & Co. Ltd. 



Colchester, London & Eton 



