212 



INDEX 



Turnip, 29, PL 9; Swedish, PL 7. 

 Turtle, embryos, PL 38; nictitating mem- 

 brane, PI. 36. 



Twig-like caterpillars, /22, PL 60. 

 Typhlichthys, 95, 



Uloborus plumipes, PL 64. 



Unicellular organisms and inheritance of 

 parental modifications, 68. 



Unselfishness in marriage, 180. 



Ursus maritimus, 126. 



Use and disuse, Intro, xi; effects of, 68; 

 inheritance of effects of, 72, 73. 



"Utility" (Romanes), 197. 



Utility, and segregation, 67; uselessness 

 of certain specific characters, 32; use- 

 lessness of organs in their beginnings, 37. 



Vaccination, 171. . 



Vanessa , c-album, PI. 56; io, 121; urtica, 



PI. 56, PL 59. 

 Variation, 7-10, 18, 39; advantageous 



when environment changing, 27 ; causes 



of, 79, 80, 81; degree of divergence, 



o, 39 ; determinate, 189; fluctuating, 18; 



in Neritina, 9, Frontispiece; in Palu- 



destrina, PI. 3; in trailing arbutus, 7; 



in Trillium, PI. 2; mutation, 18; un- 

 equal in different species, 9. 

 Varieties, of domestic animals and plants, 



29; of horses, 28, PI. 4; swamped by 



intercrossing, 41. 

 Vermiform appendix, man and orang, 166, 



PL 96. 

 "Vertebrate Embryology" (Marshall), PL 



42. 

 Vertebrates, development of, 97, 98, PI. 38, 



PI. 98; varying degrees of complexity, 97. 

 Vespa, breeding habits, 77; occidentalis, 



PL 74- 

 Vestigial structures, 93-96; in man, 164, 



PL 93-97- 

 Vigor, correlated with secondary sexual 



characters, 58. 

 Vilmorin, PL 87. 



Vinson, PL 64. 



Viola cucullata, 88; rostrata, 89. 



Violacece, 90. 



Voice, in birds, 49. 



Volucella jacialis, PL 74. 



Vries, de, Hugo, 18, 19, 39, 189, 190. 



Walking stick, 122, PL 6l. 



Wallace, A. R., 35, 47, 50, 58, 132, 144, 197, 



199, PL 73. 



Wallihan, A. G., PL 81. 

 Warning coloration, 129-134; convergence, 



134- 



Warren, E. R., 146, PL 53, PL 54, PL 57- 

 Wasps, color sense, 161 ; enemies of spiders, 



121 ; fertilizing orchid, 157, PI. 89; 



mimicked by other insects, 136, PL 70, 



PL 73; protected by stings, 130, 135; 



warning color, 130, PL 73, PL 74. 

 Waved-yellow moth, 123, PL 63. 

 Weasel, PL 67. 

 Weismann, August, acquired characters, 



67; germinal selection, 96; also, 122, 



142, 197, 199, PL 76, PL 77, PL 101. 

 Westermarck, 198. 

 Whale, hind limbs, 93, 94. 

 Wheel, invention of, 176. 

 White Mountains, flora, 112. 

 "Wild Flowers of America" (Goodale), 



PL 88. 

 Wing, of bird and of butterfly, 92; fore 



limbs of vertebrates, 92. 

 Wolf, aggressive coloration, 126. 

 Woodcock, protective coloration, 49, 119, 



PL 50. 

 Wright, Lewis, 30, PL 16, PL 18. 



Xiphophorus hellerii, PL 32. 



Yellow-jacket, warning color, 130, 135, 

 PL 74- 



Zenzera cesculi, PL 70. 

 Zittel, K., PI. 44, PL 45. 

 Zygaena, PL 56, PL 70. 



