COCOI HERON 99 
its great sickle beak into the weeds at the bottom at 
every step. When walking on land it observes these 
motions, and seems incapable of progressing without 
plunging its beak downwards into imaginary water 
at every stride. 
The Spoonbill wades up to its knees and advances 
with beak always immersed, and swaying itself from 
side to side, so that at each lateral movement of the 
body the beak describes a great semicircle in the 
water; a flock of these birds feeding reminds one 
of a line of mowers mowing grass. On dry ground 
the Spoonbill seems unable to walk directly forward 
like other birds, but stoops, keeping the body in a 
horizontal position, and, turning from side to side, 
sweeps the air with its beak, as if still feeding in the 
water. 
In the foregoing instances (and I could greatly 
multiply them) in which certain gestures and move- 
ments accompany progressive motion, it is difficult 
to see how the structure can be in any way modified 
by them ; but the preying attitude of the heron, the 
waiting motionless in perpetual readiness to strike, 
has doubtless given the neck its peculiar form. 
Two interesting traits of the Heron (and they have 
a necessary connection) are its tireless watchfulness 
and its insatiable voracity ; for these characteristics 
have not, I think, been exaggerated even by the 
most sensational of ornithologists. 
In birds of other genera repletion is invariably 
followed by a period of listless inactivity during 
which no food is taken or required. But the Heron 
