336 



Index. 



Wallace on colors of female 

 birds, 208 

 ' * on polymorphism, 238 



Walrus, 205 



Walsh, law of equable varia- 

 tion, 154 



Wart hog, 205 



Waterton on hen with male 

 characters, 106 



Weismann on parthenogenesis, 

 57, 68, 69 



Wichura on variation of hy- 

 brid willow, 124 

 Wilson on parthenogenesis, 66 

 Wollff on heredity, 22 



Xiphophorus, 198 



Yarrell on removal of oviduct, 

 105 

 ' ' on variation of dog, 150 



Zebra, hybrid, 129 



