Xo. ()3fl] INHERITANCE OE BLUE IN POULTRY 291 



It was pointed out that while, on x\\v basis <.!' tlicir ex- 

 pression in tlie phenotxpe it ap])eare(l luei-e htuical to 

 consider these factors as dotniiiants. each eh)sely linked 

 to the recessive alleloinoi'ph of the other, they may, so 

 far as the experimental e\-ideiiee shows, l)o considered as 

 true allelomorphs occui)yiii.n ideiitieal loci on homologous 

 chromosomes, and each ex}}ressing' itself iiidepeiideiitlv 

 of the other. 



The Hiidiiig of crossovers between li and K would be 

 C()iiehisi\-e eNideiiee proving the former of the two eoii- 

 ditioiis proposed. It was shown that while no ri'..»overs 

 had U'vu re])orted the critical data on the case were very 

 limited and the likelihood of crossovers being <letect.Ml 

 and isolated by bi-eeders is very sniad. It might well 



over (loe> rarely oeenr. foi" Instance, so that less than one 

 ])er cent, of the individual.^ are the i)roduct of crossover 

 gametes, the chances of <letecting them experinu^ntally 

 are small, considering the limited number of matin-s 

 (as d.'termined by the e.,ui]nHent availabh' at nn.^t ex- 

 l)oiMm..ntal in>titut ions ) which are likely to b,. <levoted to 

 a s(-arch for crossovers. 



Though much has been made of the blue An.lalusians 

 as a ••heterozygote i)henoty pically intenuediate between 

 the parental ty].e>'- it was shown that while all self-lilurs 

 so fai- found had prove<l to be hetero/yg..u> f.>r // and E, 

 they were n.>t in the strict s.nise intenne.liatr betwe.-n the 



splashed Andalusians 'a'nd white \Vyand.>tte> was re- 

 ported as selfd)lue and far darker than either ])arent. 



It was further shown in the earlier paper that ne,t 

 only r.'stricts bla.-k ])igment. so as to render ]Muinent..d 

 areas bluidi-gray in ai)i.eai'ance. but also affects the 

 sliape of the pi.mn.nit granules, so that instead of appear- 

 ing as rods as in ])lack individuals, th^y an' .|uite round. 

 In this i)articular /** is <|uite dominant over its allelo- 

 morph, whether one chooses to assume that the latter 



