No. 639] INHEEITAXCE OF BLU 



'■RY 3(37 



evidence of recombination, it seems fair to assume that 

 the white of both breeds is due to the same recessive 

 factor p in homozygous condition. 



The condition of the white Eocks and white Wyandottes 

 reported in Table II, with reference to appears clear, 

 since in all crosses with blue-splashed Andalusians (and 

 as will appear later, in the case of the Wyandotte, with 

 blue-splashed Orpingtons) which are homozygous for P 

 and R, but do not carry E, all offspring, 381 in number, 

 were without an exception, blue (see mating groups 1 to 

 4, Table II). 



On this basis blue Andalusians, PP{Re){rE), mated 

 with such recessive whites should produce blues and 

 blacks in equal numbers. Mating groups 5 to 8, inclusive, 

 in Table II show the results of such matings, which com- 

 bined give 144 blues to 129 black (136.5 to 136.5 would be 

 equality), a fair realization of the expectation. 



As would be expected from the foregoing, crosses of 

 similar recessive whites with black Andalusians {PP{rE) 

 (rE)) (see Table II, groups 9 to 11, inclusive) gave only 

 blacks. Of these there were in all 178 individuals and no 

 exceptions. 



The offspring of the crosses reported in Table II fre- 

 quently gave evidence that the recessive white parents 

 carried pattern factors as cryptomeres, but for the sake 

 of clearness these complications, which have nothing 

 directly to do with the study in hand, have been ignored 

 in summarizing the data. As was to be expected, the 

 white Plymouth Eocks carried the sex-linked pattern 

 factor for barring. All pigmented offspring by a white 

 Rock sire showed evidences of barring as soon as tlie 

 definitive feathers appeared. Two such, the olTsprlni;- of 

 a white Plymouth Rock J* and blue Aiulalusiau - are 

 shown in Fig. G, Plate II. Even at hatching, the occipital 

 spot, which may be a juvenile effect of the factor for bar- 

 ring, gave notice of the presence of the ])arring factor. 

 In the work here reported it was found possible to classify 



