The Birds’ Calendar 
to fly as you approach, but discreet enough to 
keep well in advance. They are running, and 
it is surprising with their short legs how fast 
they can cover the ground. ‘The robin some- 
times hops and sometimes runs, which is also 
true of some of the sparrows, but I have never 
seen any bird that could adopt all three modes 
of progression. Sandpipers generally show a 
curious mixture of walking and running, and 
those birds that are most at home in the water, 
are the most awkward on their feet. 
Even more interesting are the graceful vari- 
eties of flight on the wing, as illustrated in the 
long undulations of the goldfinch, the arrow- 
like course of the spotted sandpiper, the rapid 
flutter of wings in the perpendicular ascent of 
the lark, the motionless quivering and flashing 
departure of the humming-bird, the stately 
sweep of wing in sea-birds, and the majestic 
sailing of hawks and eagles. 
9 
To the field ornithologist birds will always be 
of interest chiefly for their powers of song, grace- 
ful ways, and fine plumage; but the world is 
coming by degrees to know their immense util- 
itarian significance: that in the economy of 
282 
