No. 639] IXIIERITAXCl-: OF BLUE' IN POULTRY 325 



shall breeds. Some evidence is presented wiiicii indicates 

 its presence in white Leghorns. 



4. The blue appearance of blue and blue-splashed 

 Andalusians and Orpingtons, is due to the arrangement 

 and restriction of black pigment, the result of a dominant 

 factor R. This factor has also been found in individuals 

 of the white AVvaiulotte and white Leghorn breeds, 

 though its ])r('S('nc'(' is piobably not usual in these breeds. 



5. No individuals ol' the Andalusian, Orpington, white 

 PhTnouth lioek, white AVyandotte or black Langshan 

 breeds have been found whicli did not cai i y E, E or both. 



6. The mutual relations of /»' and aic such that they 

 have never been found togelluT in the same gamete. 

 This indicates that they are allelomorphic, i.e., occupy 

 identical loci on homologous chromosomes, or, each is so 

 closely linked to the recessive allelomorph of the other, 

 {Be) and that crossing-over rarely, if ever, occurs. 



7. Xo ex ideiice of crossing-over between R and E has 

 l)een found and the tentative conclusion must be in accord 

 with that previously held, that R and E are allelomorphs. 



8. Both R and E are independent of P in their luTcdi- 

 tary behavior, though depeiulent upon its prescner for 

 their manifestation. 



9. The cooperative influence of the ovaiy is necessary 

 for a full expression of R in the regions of the neck, back 

 and saddle. 



10. On the basis of the evidence presented in the body 

 of this paper the genetic formulae of the breeds ami varie- 

 ties employed, with respect to the factor^ un.ler ohx rva- 

 tion, are usually as follows: blue-splashed Andalusians 

 and Orpingtons PP(Re)(Re); blue Andalusian- and 

 Orpingtons PP{Re)(rE) : ])lack Andalu>ians. < )rpinutons 

 and Langshans PP{rE){rE) : and white nynnnith IJocks 

 and AV yandottes p/X rE ) ( ; /•; ). 



n. The ])ossibility of th.' occunviu f factor> which 



duplicate th(^ somatic eflVct^ of // and /•; 1< pointed (mt, 

 and the relation of this i)osHl)ility to \\w pnuluction of 

 constant-breeding blues briefly discussed. 



