282 



HARRY BEAL TORREY AND BENJAMIN HORNING. 



FIG. 2. White Leghorn male about 7 weeks old, that was fed thyroid from the 

 age of two weeks. The outer pair of infant rectrices are not "quilled" and may 

 be compared with their "quilled" mates intervening. 



tassel-like distal appendage with a horny cylindrical base con- 

 tinuous with rhachis and barbs of the main body of the feather. 

 The horn cylinder he interpreted as a region in which, during 



