WEBl'UUT CHARACTER IX PIGEUXS. 



Text-fig. 3. 

 Nc3xN$ N6x N9 



15 



JOTHERSN 2W 



No JotHERsN 



W69 



Pedigree of Mr. Smalley's bird (W 69). 

 (Birds underlined ai"e supposed lieterozygotes.) 



A fui'ther and striking confirmation of this came to light this 

 year (1910), when a web-footed bird suddenly appeared in whose 

 direct ancestry on either side no webbed birds had been known 

 for at least six generations ; an investigation of the pedigree, 

 however, showed one of the birds to have been a possible hetero- 

 zygote, and on this assumption, and presuming all the subsequent 

 matings to have been DR x D, the case is quite simple. To some 



Table II. 



it may appear strange that a DR bird should have been chosen 

 in so many successive years, when the chances were even on the 

 bird being a DR ,or pure jSTormal. . It must, however, be re- 

 membered that since young were. I'eared from a lai-ge proportion 



