SIZE INHERITANCE 



199 



TABLE 29a 



Weight Inheritance in Fowls 

 After Punnett and Bailey (1914) 



borne by the Hamburg race, and one by the Sebright race. 

 Recombinations which inckide all four factors produce a race 

 larger than Hamburg, seen in the F3S from largest F2S. 

 Recombinations which include the four allelomorphs of 

 these factors produce a race smaller than Sebright, seen in 

 the F3S from smallest F2S, Table 29a. He supposes further 

 that two of the four hypothetical factors exert a greater in- 

 fluence than the other two on the total size, the influence of 

 the first being to the second as 66 to 30. The figures are purely 

 provisional and are intended to indicate a form of explanation 

 which may cover such cases satisfactorily. But it must be 

 confessed that the number of individuals studied by Punnett 

 and Bailey is small and their assumptions as to the number 

 and potency of the hypothetical factors is quite arbitrary. 



The extensive and carefully executed studies of Emerson 

 and East (1913) upon crosses of maize involving differences 

 in size and other quantitative characters afford excellent il- 

 lustrations of the usual consequences of size crosses. The 

 simplest and clearest cut cases relate to the size of the ear or 

 of the seeds borne upon it. The behavior of ear-diameter in 

 crosses is shown in Table 30. 



