broadly barred with buff and black, from the chin to the throat and neck, over the breast and down the flanks, while the central lower breast and abdomen are still in the autumn plumage of the previous September (Pl. xi. and xiii.). White terminal spots may, of course, be present on the breast and abdomen. These are a local or an individual character which will be mentioned later in dealing with varieties of feather pattern and coloration. The flank feathers of the hen in the full spring plumage show much diversity of pattern. This diversity even in the same individual bird Change of
pigmentation
improbable has led to the belief that the pattern may be changed in an unmoulted feather from the autumn plumage arrangement of red-brown and probable, reddish-black finely barred with lines of black to a much bolder barring of buflf and black. It has been surmised, from the examination of singe feathers, that the change commences in the centre of the feather on either side of the shaft, and gradually produces another pattern of a totally different colour. But can this be possible in a feather which has long been fully grown, and which has presumably been long cut off from any blood or lymph supply, and which is as dead as if it had been shed? (Pl. xii.). It is almost certain that rearrangement of the pigment or of the pattern in this way is out of the question, and the reasons for this view have already been discussed.[1]
The legs and feet of the hen Grouse in April and in May are very poorly feathered, and the claws are very long (Pl. xiii., Figs. 3, 5).
In June the legs and feet are almost bare, and the claws begin to drop off (Pl. xiii., Figs. 3, 4, 5). The precise date of this shedding of the claws is June. again really a part of the moult, and is, in consequence, equally dependent upon the health of the bird. Sick birds which have survived the spring mortality are always late in the shedding of their claws, and Shedding
of claws. equally late in the changing of their feathers. The claws are shed, both in health and in disease, but once a year, and the casting is synchronous as a rule with the disappearance of the autumn dress. The figures (PI. xiii.) by which this process is illustrated require but little explanation. The whole of the year's growth of horny black nail becomes loose on the soft and growing vascular matrix, and when quite ready to be cast can be easily pulled off like a little cap. The young nail beneath is at first soft, pink and vascular and very short, but soon hardens and deepens in colour, and in a month or two has grown to be a useful nail of horn. The transverse or circular groove which is
