Index 



*» * ^ 



Gastrula, 195, 196 

 Genealogical tree, 12, 13 

 Geological record, imperfection of, 



205 

 Germ-plasma, 328 

 Giant reptiles, 259 

 Glow-worm, courtship of, 100 

 Gregarines, 211 

 Gregarious animals, 71-74 

 Grouse attacked by weasel, 40 



Habitat, change of, 47 



Habitual actions, 155 



Haeckel, 298 



Hagfish, 253 



Halcyon, 116 



Hatteria, 260 



Heat, influence of, 313 



Heredity, 320-339 



Hermaphroditism, 188 



Hermit-crabs, masking of, 63 



Hirudinea, 234 



Homes, making of, 121-123 



Hornbill, brooding of, 114 



Horse, pedigree of, 278 



Hunting, 118, 119 



Huxley, 298 



Hydractinia, 69, 70 



Hypoblast, 196 



Ichneumon flies, 64 

 Idealism, 142 

 Impressions, 151 

 Industries of animals, 116-124 

 Infusorians, 211 



multiplication of, 38 

 Innate actions, 155 

 Insects. 241-243 



parental care of, 108 



and flowers, 28 

 Instinct, 153-166 



origin of, 163-166 

 Instincts defined, 11 



incomplete, 158 



mixed, 163 



primary, 163 



secondary, 163 

 Insulation of animals, 46 



Intelligence, lapse of, 166 

 Intelligent actions, 155 

 Iron, importance of, 19 

 Isolation, 300, 301 

 Ivory, 31 



Jellyfish, 226 



Kallima, S3 

 Kidneys, work of, 145 



Lamarck, 289-292 



Lamprey, 252 



Lancelet, 9, 252 



Land animals, 8 



Leaf insects, 54 



Leeches, 234 



Lemming, Ross's, 50 



Lemurs, 46 



Life, chemical elements of, 135- 



137 



energy of, 127 



haunts of, 3-8 



machinery of, 130, 131 



origin of, 140-142, 280 



struggle of, 32-45 



variety of, 3 



wealth of, 1-17 

 Light, influence of, 315, 316 

 Liver, work of, 145 

 Living matter, 131-135 

 Lizards, 260 

 Love of mates, 90, 91, 96 



and care for offspring, 105-116 



and death, 106 

 Luciola, courtship of, 100 

 Lucretius, 284, 285 



Macropod, parental care of, 110 

 Mammals, 9, 267-271 

 Man as a social person, 94 



considered zoologically, 340- 



346 

 Marine life, 3-6 

 Marsupials, 46 

 Masking, 61-63 

 Materialism, 141, 143 



