BREEDING POULTRY FOR EGG PRODUCTION. I73 



which indicate that high fecundity is a character of this kind, 

 but it will require prolonged analysis to decide this, because of 

 the numerous practical difficulties which attend the study of 

 fecundity. 



A great help in this analysis, as well as a contributory line of 

 evidence of much weight in supporting the general conception 

 of the manner of inheritance of fecundity set forth above, is 

 derived from the study of crosses between breeds of poultry 

 in which high and low degrees of fecundity are definite breed 

 characters. Studies of this sort carried out at the Maine Station 

 indicate that the relatively high fecundity characteristic of the 

 Barred Rock breed is inherited as a sex-limited character. In 

 this respect it behaves like a simple unit character, but this 

 does not necessarily prove that it is not a complex. More data 

 are needed to settle this point. Of much significance is the 

 fact that, whether simple or complex, fecundity is shown by 

 these experiments in cross breeding to be a character resting 

 on a definite gametic basis. 



In conclusion, I think it may fairly be said that the investiga- 

 tions here reported show in the first place that different degrees 

 of fecundity are inherited in the domestic fowl, and in the second 

 place, that in all respects wherein it has been possible, consid- 

 ering the inherent difficulties of the material and the character 

 dealt with, to make the test, the method of this inheritance is 

 in entire accord with Johannsen's concept of genotypes. 



