54 ALICE M. BORING AND RAYMOND PEARL 



male homozygous, for sex and the barred pattern factor, this 

 was proved experimentally to be the case by Goodale ('09) who 

 made crosses involving the following breeds; White Plymouth 

 Rocks (in which barring is cryptomeric), Rhode Island Reds, 

 and Buff Plymouth Rocks. These results were confirmed and 

 extended in a series of papers from this laboratory by Pearl and 

 Surface ('10 a, b, c) in which Barred Rocks and Cornish Indian 

 Games were the breeds crossed. Hadley ('10) reported the same 

 results with the same two breeds from earlier records obtained by 

 Cushman. Morgan and Goodale ('12) have reported in detail 

 the results of crossing Barred Rocks with Black Langshans (the 

 breed used by Guyer in his cytological study) and American Dom- 

 iniques with Langshans. Their findings are in entire accord 

 with those of other workers. Davenport ('06) has reported a 

 cross between White Cochin and Tosa, in which the results are 

 clearh" to be interpreted in the same way. Recently Hadlej- 

 ('13) has reported White Leghorn X Black Hamburg crosses, 

 which again show that the female is heterozygous and the male 

 homozygous for sex and barring (here carried as a cryptomere 

 by the White Leghorn). Finally, it may be said before leaving 

 the question of the barred pattern, that in unpublished work 

 from this laboratory it has been shown that crosses of Barred 

 Plymouth Rocks with (a) Campines, (b) Golden Pencilled Ham- 

 burgs, (c) Black Hamburgs, (d) White Wyandottes, and (e) 

 White Plymouth Rocks, give results in every essential accordant 

 with those already published regarding the inheritance of this 

 color pattern. 



Turning to other characters of poultrj^, breeding experiments 

 have demonstrated sex-linked inheritance of the same sort as is 

 shown by the barred patterns, in a fairly wide range of cases. 

 Bateson and Punnett ('11) in crosses of Brown Leghorns (and 

 several other breeds) with Silkies demonstrate sex-linkage of an 

 inhibiting factor influencing the mesodermal pigmentation of the 

 Silky. Goodale ('10) shows that the Brown Leghorn color pat- 

 tern is sex-linked (crosses of Brown Leghorns with White Ply- 

 mouth Rocks and White Langshans). Hagedoorn ('09) shows 

 the same essential facts regarding 'Bankiva' and 'Brown-red' 



