5i6 



INDEX 



Mayer, Mr., experiments on 



moths, 205 

 Moina, claspers of, 262 

 Moose, peculiar habits of, 58 

 Morgan, Professor Lloyd, on 



emotions, 18 

 on factors in selection, 



19, 126 

 Moth, aquatic females in, 204 



— Eyed-hawk, display of, 201 



— Ghost, scent-bottle of, 200 



— Kentish Glory, sexual differ- 

 ences in, 203 



— Oak-eggar, remarkable sense 

 of smell in, 202 



— Vapourer, remarkable sense 

 of smell in, 201 



Moths, bright colours of, 188 



— diurnal, 189 



— males, sense of smell of, 199 



— scent organs of, 200 

 Mouth, brilliant colour in birds, 



142 



Miiller, Fritz, on fragrant butter- 

 flies, 200 



Music in birds, 123 «< seq^ 



Narwhal, tusk of, 90 

 Newts, courtship of, 1 70 



— remarkable pairing habits of, 

 170 



Ocelli in birds, nature of, 98 

 Octopus, courtship of, 267 



— remarkable mating habits of, 

 268 



Ornament, controlling factors of, 



168 

 Orthogenesis, nature of, 17 

 Osborne, Professor, on factors in 



evolution, 17 

 Ostrich, roar of, 112 



Oysters, helpless condition of, 

 274 



— and social reformers, 275 



Painted Terrapin, remarkable 



courtship of, 168 

 Parthenogenesis in Crustacea, 



304 



— occurrence of, 276 



— significance of, 308 



— types of, 300 

 Peacock, display of, 95 

 Peckham, Mr., on courtship in 



spiders, 241 

 Pheasants, display of, 100 

 Pigment intensification, cause 



of, 150 

 Plovers, fatal conflicts among, 



117 



— dances of, 119 

 Plumage, evolution of, 143 

 Polyandry, human, 29 



— in birds, 1 34 



— interpretation of, 136 

 Polygamy, human, 27 



— in birds, 115, 135 



— in ungulates, 75 



— interpretation of, 76, 115, 

 135. 136 



Poulton, Professor E. B., on 



animal coloration, 186 

 on courtship of spiders, 



245 

 on sexual selection in 



spiders, 245 

 Prairie-hen, air-sacs in display 



of, 109 

 Pugnacity in birds, 1 16 



Rays, remarkable teeth of, 176 

 Reproduction, forms of, 10 

 Rhinoceros, horns of, 75 



