INDEX 



411 



Ford, E. B., change in population of 



Heodes, 215 

 — , evolution of dominance, 227 

 — , racial intergradation in Heodes, 89 

 — , sporadic variation in Heodes, 92 

 Ford and Ford, change in population 



of Melitaea, 43 

 Forficula, local dimorphism in male, 123 

 'Form,' 71 

 — , ' typical,' 82 

 Forma, 59, 64 

 Formenkreise, 59, 70 

 Formenreihe, 58 



Formica, ecological subspecies, 72 

 — , winter and summer nests, 360 

 Formicidae, see Ants 

 Fowler and Bean, variation in Capri- 

 form fishes, 126 

 Fowls, selective elimination, 205-6 

 Fox, experiments on Ciona, 37 

 — , Arctic, colour-phases, 94 

 Fox Sparrow, see Passerella 

 Franz, intermediacy in Vivipara, 89 

 Frogs, parallel variation, 326 

 Fryer, polymorphism in Acalla, 102 

 — , recombination in Papilio polytes, 25 

 Fulton, habit-differences in Oecanthus, 



146 

 — , physiological races in Oecanthus, 



120, 150 

 — , physiological races in Orthoptera, 74 

 Fumigation, variation in resistance of 



Scale Insects, 120 

 Function, variations in, 5 

 Functional adaptation, as a type of 

 compensation, 354 



, temporary substitute for true 



adaptations, 274 



Gadow, adaptive differences in Cnemi- 



dophorus, 289 

 — , colour of Elaps, 243-44 

 — , orthogenesis, 325, 326 

 — , parallel variation, 326 

 Galerida, protective coloration, 238-39 

 Galleria, immunity to Cholera Vibrio, 



38 

 Gambusia, specific differences in copula- 



tory fins, 297 

 Gammarus, mutation in eye-colours, 28 

 — , mutation-rate, 220 

 — , viability of mutants, 222-23 

 Gardner, on variation, 1 

 Gatenby, origin of germ-cells, 32 

 Gates, polyploidy, 24 

 Gause, variation in population of 



migratory locust, 321 

 Geiser, copulatory fin of Gambusia, 297 

 Gene-mutations, causation of, 27, 217, 



372 



Gene-mutations, definition, 3, 4 



— , frequency of, 6 ; see also Mutation- 

 rate 



— , role in origin of domesticated races, 

 189 



— , survival value, 223 



— , viability, 222-23 



Genes, nature of, 29 



Genetic basis of characters, 1 78 



— representation of characters, 23 

 Genetical categories, 71 



Genieys, variation in Microbracon, 20 

 Genitalia, co-adaptation of sexes, 299 

 — , differences isolating species, 151-56, 



297 

 — ■, differentiated in males only, 121, 



'53.. 

 — , differentiation in various groups, 



297 

 — , evolution of specific differences in, 



156, 296-300 

 ■ — , seasonal variation, 152 

 — , species with undifferentiated, 153-4 

 — , variation in Abraxas, 1 56 

 Gens. 71 

 Geographical races, area occupied, 79, 



IJ 7 



, compared with individual vari- 

 ants, 125 



, comparison of development in 



Vertebrates and Inverte- 

 brates, 104 



, definitions, 66, 69, 94 



— — , differences in genitalia, 152 



, differences in sex-ratio, 123-24 



, discontinuous, 1 16 



, examples, 104, 1 12 



— - — , factors determining taxonomic 



recognition of, 111, 11 7-18 



, frequency of development, 7 1 



, importance in evolution, 140, 



154 

 , influence of habits on formation 



of, 104 

 , influence of size of sample on 



definition, 71, 112 



, insular, 1 1 7 



, local dimorphism in size, 1 23 



, local parthenogenesis, 124 



, migratory species, 146 



, origin of conception, 58 



■ , Peromyscus, 39 



, seasonal occurrence, 123 



— - — , species not exhibiting, 106-8 



, also see Local races and Subspecies 



Geometridae, larva fed on ivy dis- 

 tasteful, 247 



Gerould, heredity in Colias, 282 



Giant forms, as examples of hypertely, 



333 

 , on islands, 139 



