402 



C. H. DANFORTH 



numbers under 'polydactyly present' and 'Polydactyly not 

 present' is always greater than the sum of the numbers under 

 'brachydactyly present' and 'brachydactyly not present' in 

 the same series because of the fact that Polydactyly can be 

 determined at an earlier age than brachydactyly, and in all 

 cases some embryos have died between the two critical stages. 

 In like manner, color cannot be determined till a still later 

 period, and in consequence the numbers under this caption 

 are still further reduced. 



TABLE 3 



Distribution of characteristics in embryos and chicks 



^ These totals are exclueive of the figures from 1-A and 1-C. 



Since in experiment 4 some of the hens used were not heter- 

 ozygous for Polydactyly, the data entered under that head are 

 not comparable to the corresponding data from the other ex- 

 periments. They are included here, but in brackets. 



In table 4 the data presented in table 3 are converted into 

 such a form as to enable more ready comparison between differ- 

 ent parts of the experiments. There is some question as to how 

 this could best be done, but the following method was adopted. 



