80 ANIMALS OF THE PAST 
able in many ways. Hesperornis, the western 
bird, was a great diver, in some ways the great- _ 
est of the divers, for it stood higher than the — 
king penguin, though more slender and-grace- — 
ful in general build, looking somewhat like an — 
overgrown, absolutely wingless loon. 
The penguins, as everyone knows, swim with — 
their front limbs — we can’t call them wings — ~ 
which, though containing all the bones of a — 
wing, have become transformed into powerful 
paddles ; Hesperornis, on the other hand, swam ~ 
altogether with its legs—swam so well with — 
them, indeed, that through disuse the wings ; 
dwindled away and vanished, save one bone. 
This, however, is not stating the theory quite — 
correctly ; of course the matter cannot be actu- — 
ally proved. Hesperornis was a large bird, up- _ 
wards of five feet in length, and if its ances- 
tors were equally bulky their wings were quite 
too large to be used in swimming under water, 
as are those of such short-winged forms as the — | 
Auks which fly under the water quite as much © 
as they fly over it. Hence the wings were | 
closely folded upon the body so as to offer the — 
least possible resistance, and being disused, they _ 
