Feathers ie 
closed they telescope so neatly beneath the feathers of 
the shoulder that they are not noticeable while the bird 
is in either the autumnal or vernal plumage. 
As the feathers on the flipper-like wings of a penguin 
resemble the scales of reptiles in appearance, so this 
Fie. 33a.—Ptarmigan in the fall, showing the gray autumnal plumage (which 
has replaced the brown of summer on the upper parts of the body and wings), 
gradually giving place to the white of the coming winter feathers. Wild 
birds in Alaska. (Harold Whealton, photographer. ) 
homology is carried out in the method of shedding them. 
Unlike the dropping out of feathers one by one, as in 
other birds, these come off in flakes, like the skin of a 
lizard. The feathers of the back loosen, shrivel up, and 
fade to a brownish hue before they peel away. 
