C. J. Bond 91 



on the part of the body cells of the zygote to respond in a different way 

 to the hormonic substances formed by the female and male primary sex 

 glands respectively. In normal individuals this capacity of tissue response 

 is distributed symmetrically on both sides of the body, whereas in these 

 abnormal hermaphrodite birds it would seem to be located asymmetrically, 

 and it is of interest to find that other examples of hemilateral asym- 

 metry such as the extra digit in heterodactylous fowls also occur in 

 birds. 



