INDEX 



151 



Speech, 33. 

 Spermatozoa, 40. 

 Starling, 96. 

 Sternus vulgaris, 96. 

 Stimuli to migration, see migra- 

 tion. 

 Supra-renal, Z^. 

 Syrrhaptes paradoxus, 108. 



Ultra-violet radiation, 57-64, 94, 

 115, 123. 



Vanellus vanellus, 108. 

 Vas deferens, 40. 

 Vestibule, 32. 

 Vitamin A, 60. 

 D, 57-60. 



Tactile organs, see touch. 

 Taste, 28, 29. 

 Temperature of birds, 8. 

 Temperatures, effects of low, on 



birds, 55, 56, 114. 

 , terrestrial, past and present, 



72, 73. 

 Testis, 38, 39, 40. 

 Thyroid, 38. 

 Tongue, 29. 

 Tortugas Keys, 82. 

 Touch, 29. 

 Tree sparrow, 59. 

 Tunica albuginea, 40. 

 Turbinal bones, 27. 

 Turnstone, 108. 

 Turtle, 47. 

 Tympanum, 32, 



Waders (shore birds), 77. 



Walrus, 47, 69. 



Watson, J. B., 82. 



Weather, see climate. 



Wetmore, A., 51. 



Whale, 27, 47. 



White-winged crossbill, 50. 



Wings, 9, 10. 



Wisconsin ice-age, 69, 70, 71. 



, effect on migration, 72. 



X-ray, effects on testis, 44. 



Yellow spot, see fovea. 

 Yellow-billed loon, 75. 



Zenaidura macroura, 97. 



