COCOI HERON 97 
or is in the act of watching something below it ; and 
the Heron’s life is almost a perpetual watch. Apropos 
of this manner of carrying the neck, so natural to the 
bird, is it not the cause of the extreme wariness 
observable in Herons¢ Herons are, I think, every- 
where of a shy disposition; with us they are the 
wildest of water-fowl, yet there is no reason for their 
being so, since they are never persecuted. 
Birds ever fly reluctantly from danger; and all 
species possessing the advantage of a long neck, such 
as the Swan, Flamingo, Stork, Spoonbill, etc., will 
continue with their necks stretched to their utmost 
capacity watching an intruder for an hour at a time 
rather than fly away. But in the Herons it must be 
only by a great effort that the neck can be wholly 
unbent ; for even if the neck cut out from a dead 
bird be forcibly straightened and then released, it 
flies back like a piece of india-rubber to its original 
shape. Therefore the effort to straighten the neck, 
invariably the first expression of alarm and curiosity, 
must be a painful one; and to keep it for any length 
of time in that position is probably as insupportable 
to the bird as to keep the arm straightened vertically 
would be toa man. Thus the Heron flies at the first 
sight of an intruder, whilst the persecuted Duck, 
Swan, or other fowl continues motionless, watching 
with outstretched neck, participating in the alarm 
certainly, but not enduring actual physical pain. 
Doubtless in many cases habits react upon and 
modify the structure of parts; and in this instance 
the modified structure has in its turn apparently 
G II 
