158 )F GENETICS 



ChrysopUra 

 ytlUno (Y l ). I. Mantle and lower parts grey (y 1 ). 



2. Wing-bars yellow (Y 1 ). 



3. Cheek and throat black (B). 



f the mantle is common to both, but is 

 v in pinus, the net result being an olive- 

 indebted to Dr. F. M. Chapman for the loan of 

 h these distinctions are shown. It first 

 ortk American Warblers. 

 cannot tell whether yellow or not-yellow is due to the 

 presence of a factor, but we may suppose that one or other 

 ir to the parts. The black of character 3 

 doubt a dominant. Thus pinus becomes Y*y 2 b and chry- 

 -i in y 1 Y 2 B. The Lawrencei which has the underparts 

 yellow, wing-bars white, and blachispvn^mt q&^Atawft^&nd 1 Mfco- 

 bronchmlis which has mantle ixAdam^ktfiiti&i^&iifatettow? wiftg- 

 bars ye%(ri^iftrt ao ,„i fejte & \MA \r^wV^tXWl^Xtt&Mn, 



The character,- ; , ,. ,_, u these is much 



blowing for i; 



.sternal .a^i^ozv^wta uUA<\o^s«mfoH .o .oiH 



>rrect 



: t; dif- 



onchialis as in 



east, and 



ucobronchialis 



form could be 



he absence of Y 1 with 



I ■ it that the modern observers 



- ma> be song either of 



the on r, or a song intermediate between 



o. It n t wo types have several 



ptive term "green" 

 •r is due only to a mix- 

 a: [low is the sole difference 



between tl ' era. 



