Concord, Mass,
1910.
April 18
(No 8)
[April 18, 1910]

Bitterns

and had we not known just what it was it
might well have puzzled us to account for it.
When the bird was standing or crouching
motionless under the same conditions of
environment it looked exactly like a
small patch of snow or a good-sized
sheet of white paper, lying in the marsh.
It was so very conspicuous that anyone looking
out casually over the marsh could not
have failed to notice it at the first glance.
As I have said it opened out rather slowly
as a rule and never very abruptly. Its
disappearance was effected in a corresponding
manner. With the help and under the criticism 
of Purdie and Gilbert, & with the birds showing it
conspicuously at the time, I made a model of it.