INHERITANCE OF FECUNDITY 237 



The results indicate that d" 577 was of the last (D) type, pro- 

 ducing two kinds of gametes, fkk and fUL-i. He was mated 

 with 4 barred Fi 9 9 and 4 black Fi9 9 . All of these females, as 

 in the preceding case, produced F-bearing gametes of two kinds 

 in equal numbers; Flik and FLi k. Of these matings three pro- 

 duced small families in which all of the individuals were so far 

 from being normal physiologically that they cannot fairly be 

 included in the tabulation. The details regarding them are as 

 follows. From one barred Fi 9 was produced two adult daugh- 

 ters, both of which were undersized and stunted in development, 

 and failed to lay. One of these daughters died early in the year. 

 From one of the matings with black Fi9 9 only one adult daughter 

 was obtained, which again failed to develop normally and was 

 only put into the adult house because of its interest from the 

 standpoint of color inheritance. Another of the matings with a 

 black Fi 9 produced four adult daughters. Two of these were 

 extracted whites and very small, poor specimens. The whole 

 family was saved because of these birds. Neither of them laid. 

 Of the other sisters one died early in the laying year, never having 

 laid. It, like the other members of the family, was from the start 

 a weakling. Finally the fourth sister made a winter record of 8 

 eggs. It presented the same evidence of abnormality as the other 

 sisters, and its egg record could by no means be taken as a just 

 indication of its gametic constitution in respect to fecundity. No 

 one of the seven birds under discussion would ever by any chance 

 whatever have been put in the laying house as normal individuals 

 for the study of fecundity. The only reason they ever were put 

 in was simply, as already explained, because the primary object 

 of the Fo birds as a whole was the study of color and pattern inlier- 

 itance. Even though a bird is an undeveloped weakling physio- 

 logically one may make a record of its plumage color and pattern, 

 and see whether these change with advancing age. However, 

 since these birds really were in the adult house, and in order to 

 forestall the possibility of a suggestion that any records were 

 suppressed in this study of fecundity, it has seemed advisable to 

 take the space for the above detailed discussion of the matter. 



