Female grouse, red type, feathers from flanks. Natural size. Fig. a and c (from No. 1864). g and h (from No. 226), and k (from No. 632), are varieties of the spring flank-feathers. Fig b (from No. 575) is a flank-feather from a very black hen. Fig d (from No. 1864) is an example of what is termed fine-barred dark-red winter-plumage, with narrow blank bars or lines on rather dark rufous chestnut, the latter being slightly bleached towards the tip. Fig e and f (from No. 1864) and l and m (from No. 664) illustrates intermediate stages of colouration, the feathers probably having broken through the skin when winter-conditions prevailed, and having completed their growth under summer-conditions. Fig i and n (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-conditions, producing summer breeding-plumage.