52 EDWARD A. WILSON. 
On the 19th of January, 1904, at the Cape Royds rookery in lat. 77° 45’, the 
moult from the down was in full swing, though not a bird had finished it. For contrast 
with this, at Cape Adare, some 380 miles further to the north, we saw the same moult 
in progress on the 9th of January, 1902. This serves to emphasise what has before 
been noticed, that the more southern rookeries are decidedly later than the northern 
ones, a fact which one might have expected, because the seasons are relatively far later 
for a few degrees of southing in those latitudes than in more temperate regions farther 
north. 
The colour of the feet meanwhile has also been undergoing change. When first 
the chicks are hatched their feet are very dark, and in the youngest nestling we 
obtained they were a very dusky blackish red. This rapidly alters for a clear 
bright red, which reaches its maximum in about three weeks, and then gradually turns 
to pale flesh colour on the dorsal, and black on the plantar surfaces, and these are 
retained by the bird for life. The soles of the feet are uniformly black asa rule. It is 
exceptional that such a piebald mixture of flesh pink and black is seen upon the sole as 
that figured in fig. 6, Plate X. The colour of the nails is blackish to begin with, 
but they gradually change in a couple of months to brown. The nails of the adult 
are long, and brown on the upper surface. Underneath they are darker, and there is a 
surface marking, which is due, apparently, to the wearing of the nail, the deeper parts 
of which are of a different density to the surface layers. This surface marking is found 
in the nails of all the penguins, varying much with the habit of the species, some 
inhabiting hard, some soft ground, and some at times avoiding all wear by a prolonged 
stay in the water out at sea. 
Returning now to the change in colouring which takes place at the finish of the 
first moult when the nestling down is shed, the first noticeable point is that the throat is 
white. The general colour of the upper part of the head and neck and back is bluish black, 
with a sharp demarcation line dividing it from the pure white throat, fore-neck, breast 
and abdomen. ‘The flippers are bluish black above and white beneath, with blackish 
patches at the tips, which vary much in size and may be absent. The bill in the adult 
is brick red with black on the tip and upper surface of the upper mandible, while the 
lower is black upon the sides along the cutting edge. The eyelids in the nestling are 
black, and become white only at the second autumnal moult. In the immature 
plumage the suggestion of white eyelids is given at times by the habit the bird has of 
showing the white sclerotic above the coloured iris; in the adult this habit enhances 
the value of the pure white eyelids which are so characteristic. The white ring round 
the eye which is seen in every photograph of an Adélie Penguin is therefore not due 
only to the whiteness of the lids. If the bird is watched when neither frightened nor 
excited the prominence of this white ring is much reduced and the upper lid is almost 
hidden under the black feathers of the brow. The colour of the iris varies between a 
warm or almost reddish brown and a brown which has a decided greenish tinge. In 
one at least of the younger birds the iris was a definite sage green. 
