PL XII. 



(P.Z.S. 1910. PI. AT.) 



Andre & Sleigh, Ltd 



FEMALE GROUSE, RED TYPE ; FEATHERS FROM FLANKS. 



Female grouse, red type, feathers from Hanks. Natural size. 



Fig. a and c (from \o. 1864), g and h (from No. 226), and k (from No. 632). are 

 varieties of the spring Hank-feathers. 



Fig, b (from N.I. 575' is a Hank-feathjr from a very black hen. 



Fig. d from No. 1864) is an example of what is termed line-barred, dark-red 

 winter-plumage, with narrow black bars or lines on rather dark rufous 

 chestnut, the latter being slightly bleached towards the tip. 



l-'igs. rand/ (from No. 18641 and / and in (from No. 664) illustrate interme- 

 diate stages of colouration, the feathers probably having broken through 

 the skin when winter-conditions prevailed, and having completed their 

 growth under summer-conditions. 



Fig-;, /' and it (from No. 664) illustrate the reasoning upon which is based the 

 view just mentioned ; of these two feathers there is no doubt that n was 

 being grown much later than i, and therefore more in summer-condi- 

 tions, producing summer breeding-plumage. 



