INDEX 



149 



Hoatzin, 27. 



Homing, 80-87. 



Hormone, see internal secretion. 



Howard, H. Eliot, 24. 



Iceland, 92. 

 Ichthyornis, 65, 103. 

 Instinctive behavior, 22-24, 84-86, 

 131. 



, definition of, 87, 88. 



Insulin, 38. 

 Intelligence, 17, 22. 

 Internal secretion, 36-44, 128. 

 Interstitial cells, 41, 127, 128. 

 Iris, 34. 



Jackdaw, 23. 



Junco, 59, 63, 119 et seq. 



J unco hyemalis connectens, 119. 



Jurassic, 64, 68. 



Kiwi, 28. 



Lagena, 23. 



Lamarckian hypothesis, 83, 84, 



103, 104. 

 Lapland longspur, 95-102. 

 Lapwing, 106. 

 Lashley, K. S., 82. 

 Lemming, 69. 

 Lens (of eye), 34. 

 Limpet, 49. 

 Loxia leucoptera, 50. 

 Lungs, 11. 



Magnetic field, 80. 



sensibility, 80-87. 



Magpie, 101. 



Mallard, 90-94, 128. 



Mammals, 9, 13, 16, 27, 28, 34, 



41, 47, 58. 

 Mammoth, 69. 

 Man, 16, 19. 



Membranous labyrinth, 32. 

 Memory, 24-26, 81, 83, 86. 



, inherited, 83, 84. 



Migration, definition of, 46. 



, evolution of, 90-110. 



of amphibia, 47. 



fish, 46, 47, 48, 49. 



immature birds, 49, 78, 



79,83. 



mammals, 47. 



oceanic birds, 47. 



reptiles, 47. 



■ in northern hemisphere, 53- 



60. 



tropics, 51, 105, 106. 



experiments, see experiments. 



stimuli, 113-118. 



, trans-equatorial, 116. 



and magnetic field, 80 et seq. 



during ice-age, 71, 72. 



Mind, 19. 



Morgan, Lloyd, 87. 

 Mourning dove, 97. 

 Movement, 45. 

 Movements, feeding, 49-51. 

 Musk-ox 69. 



