INDEX 



251 



Transmission in unicellular or- 

 ganisms, 160 

 Tredgold, 232 

 Treviranus, 19 

 Tschermak, 135 

 Tse-tae flies, 65 



tr 



Unit characters, 150 



Variability of living creatures, 

 14 ; a fact of life, 15 ; a con- 

 dition of organic progress, 95 



Variational stimuli, 114 



Variations, abundance of, 101 ; 

 causes of inborn, 16 ; correla- 

 tion of, 103 ; discontinuous, 

 105; origin of, 110; propor- 

 tion between frequency and 

 amount of, 102 



Vries, H. de, 22, 106, 106, 135 



W 



Wagner, 211 



Wallace, A. R., 16, 103, 107, 182, 

 208 ; and Darwin, 17, 183, 185 



Waltzing mice, 153 



Web of life, 10, 45-66 ; practical 

 importance of realising it, 61 



Wedgwood, Josiah, 4 



Weismann, 72, 85, 112; germinal 

 selection, 113, 133, 196, 207, 

 208, 210 



Weldon, experiments on shore- 

 crabs, 200 



Wenley, R. M., 41 



Whetham, 234 



White, Gilbert, on earthworms, 

 66 



Whymper, 235 



Wilde, Norman, 89 



Wilson,E. B., 164 



Zeiller, 204 

 Zygote, 152 



