Concerning Brewster's Warbler. — Additional notes on Brewster's 

 Warbler in the July Auk (pp. 481 to 482) by Walter Faxon have much 

 interest. In reading them I notice that he has not touched on one aspect 

 which may not be clear to those unfamiliar with the laws of alternative 

 inheritance. 



Supposing, as we do, that where as Brewster's Warbler is the dominant, 

 Lawrence's is the recessive hybrid, it could not be obtained from a cross 

 in which one of the parents was a pure-lineage bird of either species, as 

 the white under parts of Vermivora chrysoplera or the lack of throat 

 patch of pinus would dominate in every such case. The comparative 

 abundance of chrysoplera in the region under discussion makes it probable 

 that the Golden-wings observed mated were pure. 



Judicious shooting of chrysoplera over the leucohronchialis localitj' 

 would probably induce sufficient leucobronchialis interbreeding, so that we 

 would have the final chapter in this interesting colony; an heroic meas- 

 ure perhaps, but doubtless more specimens are frequently taken with less 

 return to science. To interfere with pinus would be unwise, as the spo- 

 radic occurrence of that species in the Golden-wing's range places it in the 

 position of the goose that layed the golden eggs. — J. T. Nichols, New 

 York, N. Y. 



