INDEX 



421 



Rensch, excessive variations in insular 



forms, 139 

 — , geographical variation, 104 

 — , insular forms dwarfed, 139 

 — , on Rassenkreise, 70 

 — , on variation, 2 

 Residual heredity, 191-92, 226-27 

 Rhine and Macdougall, experiments 



on rats, 40 

 Rhipidura, change in population, 215 

 Rhyacionia, death-rates in nature, 193 

 Richards, colour-convergence in Bom- 

 bus, 259 

 — , correlation of characters in Vespa, 



.173 



— , differentiation of male genitalia, 



.153 

 — , dispersal of Helops, 1 47 

 — , interbreeding of polymorphic 



species, 149 

 — , scent-production, 293 

 — , seasonal occurrence of Sphaero- 



ceridae, 145 

 — , sexual selection, 292 

 Richards and Robson, insular Mollusca, 



137 

 du Rietz, on the biotype, 72 



, on the lower systematic cate- 

 gories, 59, 64 



Riley, J. H., insular forms of birds, 137 



Riley, N. D., ' age and area,' 86 



Rivers as barriers, 134 



Robertson, oligolectic bees, 349 



Robson, adhesive organs in Cephalo- 

 poda, 308 



— , characters of abyssal fauna, 269-70 



— , continuous and discontinuous varia- 

 tion, 88 



— , convergence, 61 



- — , correlation, 161, 170 



— , criticism of Bumpus's observations 

 on Passer, 210 



— , criticism of Weldon on Carcinus, 



197 

 — , Hebridean mammals, 137 

 — , induced modifications, 31, 35 

 — , non-heritable variant of Paludes- 



trina, 20 

 — , origin of gene-mutations, 217 

 — , permanent isolation, 141 

 — , physiological differentiation, 74 

 — , size-variation in Mollusca, 156 

 — , spread of Paludestrina, 322 

 — , spread of Planorbis, 322 

 — , spread of Slipper Limpet, 322 

 — , sterility, 157 

 — , survival of mutants without aid of 



selection, 319 

 — , variation in ectodermal deriva- 

 tives, 5 

 Rocellaria, character of shell, 336 



Rodents, coat-colour on lava fields, 236 



Rokizky, alteration of mutation-rate, 29 



Roosevelt, countershading, 242 



Roosevelt and Heller, protective re- 

 semblances in mammals, 235 



Roszkowski, non-heritable characters 

 in Mollusca, 81 



Rothschild and Hartert, protective 

 resemblance in Galerida, 239 



Rothschild and Jordan, on the term 

 ' variety,' 63 



Rudistes, size of valves, 33 1 



Russell, absence of qualitative division 

 in chromosomes, 179 



— , death-rates in marine Mollusca, 194 



— , ' Psycho-biology,' 344 



Ruthven, determinate evolution, 325 



Ruxton and Schwarz, intermediacy 

 due to crossing, 88 



Sagartia, species with different methods 



of reproduction, 123 

 Salamandra, experiments on, 38 

 Salinity, effects on Mollusca, 81 

 Salmon, adaptive differences, 287 

 — , effects of external factors, 169 

 Salpidae, determinate evolution, 325 

 Salt, death-rates in Cephus pygmaeus, 



. J 93 

 — , size of flies determined by food- 

 supply, 79 

 Satyrus, distribution of forms with 



similar genitalia, 154 

 Scapanorrhynchus, age of species, 131 

 Scarabaeidae, high and low males, 12 

 Scardafella, trends in, 48 

 Sceliphron, polymorphism, 103 

 Scent-production and -organs, 148, 



150, 293 

 Schmalfuss and Werner, nature of 



genes, 29 

 Schmidt, characters of ^oarces, 287 

 — , differences in breeding habitat, 146 

 — , effect of external factors on various 



fish, 169 

 — , geographical variation of Blenny 



and Eel compared, 105 

 — , hereditary stability of races, 70 

 — , races of £oarces, 69, 114 

 — , trend in Atlantic Cod, 50 

 — , variation in the Cod, 114 

 Schnakenbeck, study of fish shoals, 92 

 Schroder, experiments on Gracilaria, 



Abraxas and Phratora, 36 

 Schubert,seasonal occurrence of dragon- 

 flies, 145 

 von Schweppenburg, isolation of races 

 of Lasiocampa, 143, 154 



, local interspecific intergradation, 



103, 158 



