Fig. 2. (a) Breast Feathers of normally colored Wood Thrush Hyloeichla mustelina, 

 (b) Breast Feathers of melanistic Wood Thrush. 



Fig. 3. (Upper) Normal White-throated Sparrow, Zonotrichia albicollis ; (Lower) Melanistic 

 White-throat, three years in humid atmosphere. 



; 



