20
Back Bay Basin,
Boston, Mass.
1909
Feb. 27
(No 20)
Whistler courtship
  Back thrust of head and neck ending in
Folded duck-skin posture.
Back thrust & fold skin posture
  This was sometimes made from the masthead
posture but far oftener directly from the normal
position by a single, uninterrupted upward and
backward moving of the head and neck. The movement
was so swift and sudden that I often failed to 
follow it even when watching for it with my attention
concentrated on a bird which I felt confident was
about to make it: At its termination the neck
lay extended along the back and so very flat and
close that it was scarce noticeable. The head
showed conspicuously enough resting, apparently on
the occiput at a point anywhere between the middle 
of the back and the rump, with the widely parted