THE PERCHING Birps. 67 
and bobbing motion of the head. Every movement 
suggested an aquatic life; and while so engaged the 
only sound they make is a single, short, sharp chirp 
when alarmed. But there are occasions when all 
this is changed. In the early summer it finds time 
to leave the water’s edge and go deeply into the 
swamps, where the undergrowth is almost impene- 
trable. It moves amid this tangle with the same 
ease that marked its progress on the pebbly beach 
or over the yielding mud-flat. But when in the 
woods it does something more than merely chirp. 
In an extensive tide-water swamp, where I have often 
found these birds, I have heard them sing, seldom in 
light of day, but often in the gloaming. Clear, flute- 
like notes in rapid succession were poured forth, then 
shriller and wiry ones, and these followed by a trill 
that slowly died away. The song is not always the 
same, and probably no two individuals perform it 
quite alike. To my hearing, it bears no resemblance 
to the evening song of the oven-bird. The nests of 
the two water-thrushes are always on the ground. 
and those of the short-billed species that I have seen 
were composed almost wholly of dried sphagnum 
and lined with fine grass. 
A family of warbler-like birds, yet with character- 
istics quite their own, that are strictly arboreal, and 
so, naturally, insect-eaters, are the plainly colored, 
but neat, active, musical Vireos, or Greenlets. The 
facts that they are greenish-olive above and yellow 
or yellow-white below, and have rather stout, hooked 
beaks that seem better adapted than a warbler’s bill 
for holding on to big insect game,—these points will © 
