454 
PALLAS’ DIPPER, 
gitudinal, half covered by a membrane ; tongue cartilaginous 
and bifid at tip. Their wings are short and rounded, furnished 
with a very short spurious feather, and having the third and 
fourth primaries longest ; the tail short, even, and composed 
of wide feathers ; the nails large and robust ; the lateral toes 
are subequal, the outer united at base to the middle one, the 
hind toe being short and robust. The female is similar to the 
male in colour, and the young only more tinged with reddish. 
They moult but once in the year. 
These wild and solitary birds are only met with singly, or 
in pairs, in the neighbourhood of clear and swift-running 
mountain streams, whose bed is covered with pebbles, and 
strewed with stones and fragments of rock. They are re- 
markably shy and cautious, never alight on branches, but keep 
always on the border of the stream, perched, in an attitude 
peculiar to themselves, on some stone or rock projecting over 
the water, attentively watching for their prey. Thence they 
repeatedly plunge to the bottom, and remain long submerged, 
searching for fry, Crustacea, and the other small aquatic animals 
that constitute their food. They are also very destructive to 
musquitoes, and other dipterous insects, and their aquatic 
larvae, devouring them beneath the surface. They never avoid 
water, nor hesitate in the least to enter it, and even precipi- 
tate themselves without danger amidst the falls and eddies of 
cataracts. Their habits are, in fact, so decidedly aquatic, that 
water may be called their proper element, although systema- 
tically they belong to the true land birds. The web-footed 
tribes swim and dive ; the long-legged birds wade as long 
as the water does not touch their feathers ; the dippers alone 
possess the faculty of walking at ease on the bottom, as 
others do on dry land, crossing in this manner from one shore 
to the other, under water. They may be often seen gradually 
advancing from the shallows, penetrating deeper and deeper, 
and, careless of losing their depth, walking with great facility 
on the gravel against the current. As soon as the water is 
deep enough for them to plunge, their wings are opened. 
