236 



INDEX 



Tiger, aggressive resemblance in, 



131 

 Tiger, sabre-toothed, 56 

 Tiger-moth, caterpillar of, 136 

 Time, insufficiency of, 170 

 Torpedo, electric organ of, 170 

 Trilobites, 57 



Trout, change of colour in, 120 

 Trumpeter pigeon, 28 

 Tubifex, colour of, 119 

 Tubular stage in Amphioxus, 1 12 

 Tumbler pigeon, 28 

 Turbit pigeon, 28 



Vanessa lev ana and prorsa, 121 

 Variable protective resemblances, 



130 

 Variation, in ants, 43 



birds, 44 



bramble, 45 



butterflies, 44 



cabbage, 46 



Foraminifera, 43 



hyacinths, 43 



man, 45 



reindeer, 43 



sheep, 43 



snails, 44 



under domestication, 46 



with habits, 44 



with heredity, 37 

 " Variation of animals and plants 



under domestication,'' 214 

 Variations, alleged uselessness of 

 small, 163 



importance of small, 48 



" Various contrivances by which 

 orchids are fertilised by in- 

 sects,'' 215 

 Vermes, fossils of, 60 

 Vertebrata, characters of, 174 



classification of, 174 



fossils of, 60 



origin of, 173 

 Vestiges, 95 

 Vicuna, 71 

 Volvox, 114 

 Voorhelm, 43 



Wallace, Alfred Russel, 21 

 chart of natural selection, 37 

 conditions of mimicry, 140 

 origination of idea of survival 

 of the fittest, 212 

 Warning colours, 123, 133 

 Webb's channel swim, 73 

 Wedgwood, Josiah, 201, 220 

 Whale, probable extinction of, 69 



rudimentary teeth of, 95 

 Wisdom teeth of man, 194 

 Wombats, geographical distribu- 

 tion of, 74 

 Words, rudimentary letters in, 97 

 Wright, Seth, 35 



Xenophora, 132 



Zebra, colour of, 125 

 Zocea stage of crab, 90 



of prawn, 81 

 "Zoonomia," by Erasmus Dar- 

 win, 202 



Printed ty Ballantyne, Hanson & Co. 

 London and Edinburgh. 



