340 The Bird 
flyers. The latter, in fact, use their wings, the feathers 
of which have very stiff and long quills, as much in diving 
under water as in flying in the air, and, strangely enough, 
they are said to swim breast upward, propelling themselves 
by means of both wings and feet. Grebes, too, are very 
weak of wing, and these birds cannot rise from level ground, 
no matter how much of a fluttering run is taken, and even 
in the water much splashing and headway are needed. 
Perhaps the most wonderful birds in the world are 
penguins, and the strangest part of these strange birds 
is the wing. There is no doubt that they are descended 
from birds which possessed the power of flight; but the 
penguins have discarded this gift and have returned to 
a life in the sea, whence in long ages past their forebears 
had crawled out upon land. As in the ostriches, the 
relics of flight-feathers have increased greatly in number, 
but have become small and scaly, and the wings have 
virtually become flippers or fins. Instead of a given num- 
ber of feathers, divided into well-marked series, the pad- 
dles of a penguin are covered thickly with small feather- 
scales, and the rigidity of the wings, together with the 
rotary movement at the shoulder-joint, make the propeller 
of a ship an apt simile. The colour of the feather-scales 
on the upper side of the wing is dark, like the back of 
the bird, but those on the under side have run rampant, 
the white and black being mixed irregularly, not corre- 
sponding even in the two wings of an individual bird. 
The outline of the wing is exactly like that of a shark’s 
fin, the flatness and breadth including even the bones, 
while (also like a fin) all of the bending quality of a wing 
