INDEX. 





plays of lions, 120, 129; of vis- 

 cacha, 157 ; of lambs, 192 ; of 

 mocking bird, 200; of weasels, 

 207, 209 ; of various birds, 212 ; of 

 cows, 209 ; of Rupicola erocea, 225 ; 

 on sexual selection, 231, 238, 246 ; 

 duet by woodpeckers, 256 ; on 

 plumage of female birds, 281. 



Huggins, a musical dog, 189. 



Humboldt, flying flsh, 101 ; play of 

 jaguar, 123 ; of toucan, 139 ; vocal 

 organs of howling ape, 273. 



Hume on instinct, 40. 



Hunting plays, 120. 



Hyena, 142. 



Hypnotism, 304. 



Hysteria, 304, 312. 



Ibis, 139, 211. 



Illusions, 124, 130, 299. 



Imitation, 8, 14, 72, 74, 273, 281 ; by 

 gregarious animals, 76, 181 ; in 

 nest-building, 153; in art, 167, 

 328; constructive, 167, 180; so- 

 cial I, 207 ; inner, 162. 



Imitative play, 178, 223, 302. 



Inheritance of acquired characters, 

 45, 49, 54, 57, 71, 182, 227. 



Insect, 100, 130, 140, 220. 



Instinct, 13, 24, 47, 62, 67, 70, 152, 

 161, 177, 243, 249, 289. 



Intelligence of animals. 26 ; of birds, 

 251 ; relation to instinct, 50, 69 ; 

 advancement through play, 72; 

 through imitation, 74. 



Jacana, 212. 



Jackdaw, 148, 159. 



Jaguar, 123, 144. 



James, play as instinct, 8, 43 ; inher- 

 itance of acquired characters, 56 ; 

 instinct and intelligence, 69 ; imi- 

 tation, 78, 178, 207; acquisitive- 

 ness, 164; curiosity, 214, 219; at- 

 tention, 124. 



Janet, on double personality, 307, 

 314. 



Jean Paul, surplus energy, 2 ; ex- 

 perimentation, 85. 

 Jeens, imitation in a dog, 191. 



Kant, on artificial selection, 46 ; 

 likeness to Weismann, 54 ; natu- 

 ral and artistic pleasure, 303; 

 double personality, 304 ; influ- 

 ence of Schiller, 318; on free- 

 dom, 322. 



Kastner, on parrots, 203, 227. 



Keanastor, 220. 



Keiraplasm, 53. 



Keller, on monkeys, 184; on the 

 song of nightingales, 277. 



Kirchner, on instinct, 32; intelli- 

 gence of birds, 252. 



Kite, 260. 



Kleptomania, 165. 



Krauss, 104. 



Kristan von Hamle, on parrots, 203. 



Kropotkine, on cats, 126. 



Kussmaul. on Keimarus, 38. 



Lamarckian theory, 45, 46, 50, 57. 

 Landmann, on double personality, 



304. 

 Lange, conscious self-deception, 



292, 300; nature and art, 310; 



pendulum, 311 ; illusion, 326. 

 Lapwing, 109, 260, 264. 

 Lazarus, 16, 20, 324. 

 Lehmann, 288, 325. 

 Leibnitz, imitation in a dog, 189. 

 Lenz, on goats, 113; martens, 122; 



foxes, 123 ; rodents, 217 ; cranes, 



262 ; finches, 275. 

 Leopard, 141. 

 Leroy, 26, 50, 214, 298. 

 Lessing, 88. 

 Leutemann, 186. 

 Levaillant, 297. 

 Lewes, 48. 



Linden, on cockatoos, 95, 139. 

 Lindsay, on the water rat, 158. 

 Lion, 97, 141, 210. 



