INDEX 



315 



Forbes, Dr. H. O., on deceptive 



coloration in a spider, 240 

 Frigate-bird, air-sacs in display 



of. III 



Frilled-lizard, courtship of, 165 

 Frogs, concerts of, 171 



— courtship of, 169 



— singing like a Greenfinch, 173 

 Fur-seals, courtship of, 81 

 polygamy of, 8 1 



precocious sexual instincts 



in, 86 



Germ-plasm, nature of, 11 

 Giraffe, kick of, jz 



— strong smell of, 68 

 Grasshopper, air-bladder of, 219 



— stridulating organs of, 218, 

 221 



Grebe, Great-crested, courtship 



of, 151 

 Groos, Professor, on emotions, 



18 



Hippopotamus, bloody sweat of, 

 69 



— teeth of, 72 

 Hooded-seal, air-sac of, 88 

 Hormones, nature of, 16 



— part played by, 146, 147 

 Horns, evolution of, 51 

 Hottentots, remarkable pecu- 

 liarities of, 31 



Howard, H. E., on importance 

 of " territory," 140 



on play in warblers, 121 



on sexual selection, 1 38 



Huxley, Mr. JuUan, on the beha- 

 viour of Mallard, 149 



on the Great-crested 



Grebe, 151 



Hypertely, meaning of, 125, 127 



Image, Professor Selwyn, on 

 Vapourer Moth, 201 



Impotency, possible conse- 

 quences of, 155 



Ingram, Sir William, on display 

 of King Bird-of-Paradise, 102 



Insects and sexual selection, 192 



Katydid, song of, 222 

 Kinetogenesis, meaning of, 80 



Leptodora, olfactory sense of, 



262 

 Life, lowest forms of, 3 et seq. 

 Lion, mane of, 77 



— polygamy in, 81 



Lizards, courtship of, 165 et seq. 



— fighting among, 167 

 Locusts, ear of, 220 



— remarkable ornaments of, 225 

 Lucas, Dr. F. A., on sea-lions, 86 



Males, degenerate, 307 



— first to acquire new features, 9 



— lead in new departures, 190 



— where superfluous, 307 

 Mallard, remarkable behaviour 



of, 149 

 Man, evolution of, 22 et seq. 

 " Mate-hunger," part played by, 



147 



power, importance of, 5 



Mating, preferential, 155 

 May-flies, dance of death of, 



229, 232 



nuptial flight of, 232 



remarkable eyes of male, 



231 

 May-flies, remarkable use of 

 stomach in, 230 



